What is this insect found in a shower?

I hope the picture is clear enough, I've found a worm like insect like the one below a little while ago in my shower, and today I found another one. I've never seen something like this. I would say it is slightly bigger than a centimeter.

Location: Netherlands Why do they come in my shower ?

It is a species of silverfish such as Ctenolepisma longicaudata or Lepisma saccharina for examples (thanks @RHA for correction in comments).

Silvefish are well known very resistant pest typically found in washrooms and sometimes in kitchens. They are not directly dangerous but can cause property damage. Here is a webpage giving advice on how to get rid of them

This Insect Has The Only Mechanical Gears Ever Found in Nature

To the best of our knowledge, the mechanical gear—evenly-sized teeth cut into two different rotating surfaces to lock them together as they turn—was invented sometime around 300 B.C.E. by Greek mechanics who lived in Alexandria. In the centuries since, the simple concept has become a keystone of modern technology, enabling all sorts of machinery and vehicles, including cars and bicycles.

As it turns out, though, a three-millimeter long hopping insect known as Issus coleoptratus beat us to this invention. Malcolm Burrows and Gregory Sutton, a pair of biologists from the University of Cambridge in the U.K., discovered that juveniles of the species have an intricate gearing system that locks their back legs together, allowing both appendages to rotate at the exact same instant, causing the tiny creatures jump forward.

The gears are located on the top segment of each of the insect’s hind legs

The finding, which was published today in Science, is believed to be the first functional gearing system ever discovered in nature. Insects from the Issus genus, which are commonly called “planthoppers,” are found throughout Europe and North Africa. Burrows and Sutton used electron microscopes and high-speed video capture to discover the existence of the gearing and figure out its exact function.

The reason for the gearing, they say, is coordination: To jump, both of the insect’s hind legs must push forward at the exact same time. Because they both swing laterally, if one were extended a fraction of a second earlier than the other, it’d push the insect off course to the right or left, instead of jumping straight forward.

The gearing is an elegant solution. The researchers’ high-speed videos showed that the creatures, who jump at speeds as high as 8.7 miles per hour, cocked their back legs in a jumping position, then pushed forward, with each moving within 30 microseconds (that’s 30 millionths of a second) of the other.

The finely toothed gears in their legs allow this to happen. “In Issus, the skeleton is used to solve a complex problem that the brain and nervous system can’t,” Burrows said in a press statement.

The gears are located at the top of the insects’ hind legs (on segments known as trochantera) and include 10 to 12 tapered teeth, each about 80 micrometers wide (or 80 millionths of a meter). In all the Issus hoppers studied, the same number of teeth were present on each hind leg, and the gears locked together neatly. The teeth even have filleted curves at the base, a design incorporated into human-made mechanical gears because it reduces wear over time.

To confirm that the gears performed this function, the researchers performed a neat (albeit morbid) trick with some dead Issus. They manually cocked their legs back in a jumping position, then electrically stimulated the main jumping muscle in one leg so that the leg extended. Because it was rotationally locked by the gears, the other non-stimulated leg moved as well, and the dead insect jumped forward.

The main mystery is the fact that adults of the same insect species don’t have any gearing—as the juveniles grow up and their skin molts away, they fail to regrow these gear teeth, and the adult legs are synchronized by an alternate mechanism (a series of protrusions extend from both hind legs, and push the other leg into action).

Burrows and Sutton hypothesize that this could be explained by the fragility of the gearing: if one tooth breaks, it limits the effectiveness of the design. This isn’t such a big problem for the juveniles, who repeatedly molt and grow new gears before adulthood, but for the mature Issus, replacing the teeth would be impossible—hence the alternate arrangement.

There have been gear-like structures previously found on other animals (like the spiny turtle or the wheel bug), but they’re purely ornamental. This seems to be the first natural design that mechanically functions like our geared systems.

“We usually think of gears as something that we see in human designed machinery, but we’ve found that that is only because we didn’t look hard enough,” Sutton said. “These gears are not designed they are evolved—representing high speed and precision machinery evolved for synchronisation in the animal world.”

About Joseph Stromberg

Joseph Stromberg was previously a digital reporter for Smithsonian.

Insect Repellent Buying Guide

If you live in an area where mosquitoes or ticks (or both) are common, it’s important to protect yourself against the diseases these biting bugs can carry. The list of diseases you can catch from mosquitoes and ticks has grown in recent decades. Zika, transmitted by mosquitoes, and Powassan, transmitted by ticks, are two distressing examples. And even the number of people every year coming down with more familiar diseases like Lyme is increasing.

Our insect repellent ratings identify which products work best against mosquitoes and ticks. (We no longer test our products against ticks, but past test results and our research indicate that repellents that work well against mosquitoes also tend to be effective against ticks.)

Choosing the right repellent matters: Our top products provide several hours of protection, and some of our lowest-scoring ones fizzle out in as little as 30 minutes. So arm yourself with one of the high-performing repellents.

How We Test Insect Repellents

We begin our insect repellent tests by applying a standard dose of repellent to a measured area of skin on our test subjects’ arms. (The standard dose is determined from the Environmental Protection Agency’s product testing guidelines.)

After 30 minutes, these brave volunteers place their arms into the first two of four cages of 200 disease-free mosquitoes for 5 minutes. Our testers watch closely to see what happens inside the cage, and they count up every time a mosquito lands on a subject’s arm, uses its proboscis (its long mouth) to probe the skin in an attempt to find a capillary, or bites the subject’s arm and begins to feed—which the testers can tell by watching for the insect’s abdomen to turn from gray to red or brown.

After 5 minutes, the subjects withdraw their arms, then repeat the process by placing their arms into a second pair of cages of disease-free mosquitoes of a different species, for another 5 minutes. The subjects then walk around for about 10 minutes, to stimulate sweating—this is to mimic a real-world setting, in which users might be active while wearing repellent.

Half an hour later, this procedure is repeated once, and then again once every hour after that until a repellent fails our test, or until 8 hours have passed since it was applied. We consider a failure to be a “confirmed mosquito bite”—two bites in one 5-minute session inside the cage, or one bite in each of two consecutive 5-minute sessions.

Go Inside the Lab

Watch our video below for more details on how we test insect repellents.

Ingredient Info

You might not think to read the label before buying an insect repellent. That’s a mistake, because the active ingredient and concentration matter to both effectiveness and safety.

The top-performing products in our tests contained one of these three active ingredients: deet, oil of lemon eucalyptus, or picaridin. And all are safe when used as directed. Here’s what you need to know about active ingredients.

Many people assume that the more deet (N,N-diethyl-meta-toluamide) a product contains, the better. But our tests find that there’s no need to use higher concentrations products with 15 to 30 percent deet can provide long-lasting protection against mosquitoes and ticks. And some research suggests that the remote risks associated with deet, like rashes and even seizures, may occur when too much of the product is used. (See below for how to safely apply all repellents.)

That’s why we say everyone should avoid repellents with more than 30 percent deet. At 30 percent and below, deet is safe for pregnant women and children who are at least 2 months old. But it’s important not to go too low, either in our tests, products with just 10 or 7 percent deet don’t work well.

Shop Ben’s Insect Repellent on Amazon


This is a synthetic repellent modeled after a compound that occurs naturally in the black pepper plant. We recommend two 20 percent picaridin products and one 10 percent picaridin product, all sprays.

But concentration matters: Another product, with just 5 percent picaridin, is one of our lowest-scoring insect repellents. And, at least when it comes to picaridin, form seems to matter. Of two other picaridin products in our tests, we find that neither a 20 percent lotion nor a 20 percent wipe works as well as the 20 percent picaridin sprays. Finally, while picaridin is deemed safe, even for use on infants who are at least 2 months old and on pregnant women, it can irritate your skin and eyes, so you should use it carefully.

Shop Sawyer Insect Repellent on Amazon

Oil of Lemon Eucalyptus

This is a refined version of a naturally occurring compound extracted from the gum eucalyptus tree. It can also be produced synthetically. Four products in our insect repellent ratings that contain 30 percent oil of lemon eucalyptus (OLE) do well in our tests.

OLE also appears to be safe when used properly, though it can cause temporary eye injury. Pregnant women can use it, but the Food and Drug Administration recommends against using it on children younger than 3.

Shop Repel Lemon Eucalyptus on Amazon

IR3535 and 2-Undecanone

Although these active ingredients are included in the Centers for Disease Control and Prevention’s list of recommended insect repellents, in our tests, products with these two ingredients offer limited protection and are less effective than products containing deet, picaridin, and OLE.

IR3535 is a synthetic compound that is structurally similar to a naturally occurring amino acid. And 2-undecanone is a synthesized version of a compound found in rue, wild tomatoes, and several other plants. Both products appear safe, but as with all repellents, they should be used with caution, especially on children.

Shop Coleman Insect Repellent on Amazon

The Buzz: Things to Think About

Be Wary of ‘Natural’ Repellents
Several makers of “natural” insect repellents (which typically contain essential plant oils such as cedar, citronella, clove, lemongrass, peppermint, and rosemary) claim that their products can help ward off mosquitoes, including those that carry the Zika virus. But our tests show that these active ingredients aren’t very effective, often failing in our tests within half an hour.

Don’t Buy Based Only on Ingredient or Concentration
Some of our top-rated products contain picaridin, but so do some of our lower-rated ones. Concentration and form probably explain some of that difference: High-scoring products are sprays that contain 20 percent picaridin, and the low-scoring ones contain less picaridin or come in a lotion or wipe form. Our tests have shown that products with deet, in concentrations of 15 to 30 percent, are more likely to provide reliable protection.

Don’t Use Combination Sunscreen-Insect Repellent Products
We’re not fans of these combo products—sunscreen should be reapplied every 2 hours, which could overexpose the user to the chemicals in repellents.

The Right Way to Apply Insect Repellents

Proper application and use is essential, both for maximum protection and to avoid possible side effects, including skin or eye irritation. That means:

• Apply repellent only to exposed skin or clothing (as directed on the product label). Never put it on under clothing.
• Use just enough to cover and only for as long as needed heavier doses don’t work better and can increase risks.
• Don’t apply repellents over cuts, wounds, or irritated skin. When applying to your face, spray first on your hands, then rub in, avoiding your eyes and mouth, and using sparingly around ears.
• Don’t let young children apply. Instead, put it on your own hands, then rub it on. Limit use on children’s hands because they often put their hands in their eyes and mouths.
• Don’t use near food, and wash hands after application and before eating or drinking.
• At the end of the day, wash treated skin with soap and water, and wash treated clothing in a separate wash before wearing again.
• If you’re planning to use repellents on your clothes, note that most of the ones we test can damage leather and vinyl, and some of them stain synthetic fabrics.

Shopping links are provided by eBay Commerce Network and Amazon, which makes it easy to find the right product from a variety of online retailers. Clicking any of the links will take you to the retailer’s website to shop for this product. Please note that Consumer Reports collects fees from both eBay Commerce Network and Amazon for referring users. We use 100 percent of these fees to fund our testing programs.

Built-In Straws

“Screw plastic straws,” Prudic says. Butterflies “have their own personal drinking straw,” a long proboscis through which they drink nectar.

But some bugs aren’t vegetarian. They drink other bugs.

Adult green lacewings are dainty, delicate little insects, “but as kids they are just terrors,” Prudic says, particularly to aphids.

“[Lacewings’] mandibles are these hollow straws, and they just walk up to an aphid and they just pierce them on one on each side and just suck them dry.”

The ultimate protein shake.

Have a question about the weird and wild world? Tweet me or find me on Facebook. Weird Animal Question of the Week answers your questions every Saturday.

Giant wood moth: ‘very heavy’ insect rarely seen by humans spotted at Australian school

A giant moth with a wingspan measuring up to 25cm has been found at a Queensland school next to a rainforest.

Builders found the giant wood moth, the heaviest moth in the world, while constructing new classrooms at Mount Cotton state school.

Giant wood moths are found along the Queensland and New South Wales coast, according to the Queensland Museum. Females can weigh up to 30 grams and have a wingspan of up to 25cm. Males are half that size.

They have an extremely short life cycle with adults living only a matter of days. They die after mating and laying eggs.

The school’s principal, Meagan Steward, said the moth was “an amazing find”.

Steward said due to the school’s location it was not unusual to find a range of animals on the grounds such as bush turkeys, wallabies, koalas, ducks, the occasional snake and once a turtle in the library. “A giant wood moth was not something we had seen before,” she said on Wednesday.

Giant wood moths are found along the Queensland and NSW coast. Females can weigh up to 30 grams and have a wingspan of up to 25cm. Photograph: Mount Cotton state school/Facebook

The initial ABC news report and photos of the moth generated so much media interest the school was forced to direct questions about the moth to the Queensland education department.

Chris Lambkin, the curator of entomology at the Queensland Museum, said giant wood moths, or Endoxyla cinera, could be found from coastal Queensland down to southern NSW. While not uncommon they were rarely seen by humans, she said.

Lambkin said this was likely due to several factors including the adult moths’ short life span and the fact most people lived in urban areas where the invertebrate was not found.

“The female moths also don’t fly very well,” she said.

“So most people, if they do see one, it has emerged as an adult and crawled up a tree trunk or a fence post and is waiting for the male to come along. Normally people don’t see them with their wings spread out so you don’t realise just how big they are but if you actually lift them up they’re very heavy.”

As small caterpillars, the invertebrates have purple and white banding and bore into the trunks of smooth-barked eucalypts in parks and gardens. They lose the banding as they grow into larger grubs.

Insects in the City

Pillbugs are one of the most common arthropods in most Texas landscapes.

Pillbugs are common inhabitants of landscapes and garden sites around buildings. Among the few crustaceans that have fully adapted to life on land, pillbugs are relatively simple in their construction, but interesting in the way they have adapted to terrestrial life. Occasionally pillbugs become pests around the home, and that is what this factsheet is about however if you are interested in learning more about these small creatures, see the section “For more information” at the end of this publication.


The common pillbug, Armadillium vulgare, is a familiar inhabitant of mulched gardens and flower beds. Sometimes called “roly-polies” because of their habit of rolling up into a tight ball when disturbed, pillbugs are small (generally less than 1 cm-long), brownish to grey-black in color, and armored in appearance. The head and abdomen are relatively small, but the thorax is composed of seven overlapping plates. There are seven pairs of legs.


In most years pillbugs content themselves in feeding harmlessly on decaying vegetable matter in and on the soil. However when abundant–as in years of high rainfall–they can become a significant pest of landscape plants. Most feeding takes place in the evening or at night. Feeding pillbugs readily feed on small garden plants, and new transplants can be eaten to the ground overnight. Some of the plants attacked include hosta, pansies, blue lobelia, cardinal flower, English primrose, Allyssum, Dahlberg daisy, zinnia, verbena, and blackfoot daisy. Garden vegetables are also susceptible, especially strawberries and other plants with fruits that contact the soil. During the day, pillbugs can be found in moist areas under mulch or leaves and vegetable debris of all kinds. Cooler portions of compost piles can also harbor large numbers of pillbugs. Pillbugs often bury themselves several inches beneath the soil surface to avoid hot, dry conditions. Pillbugs are prolific, giving birth to 30-80 young per brood. In Texas pillbugs may produce two to three generations per year. Adult pillbugs are relatively long-lived, with some surviving several years.


The best way to eliminate pillbugs is to destroy their breeding and hiding sites. Eliminate unnecessary piles of leaves, grass clippings and mulch. Flower pots, planters, dog houses, firewood, bricks or other objects that sit directly on the ground should be elevated to allow air-flow and drying underneath. Adjust irrigation systems so that the soil around your home has a chance to dry between irrigations. When abundant, pillbugs can enter homes and become a nuisance. This can be prevented by careful sealing of doors and cracks in foundations. Pillbugs are harmless and can be removed by hand, or by vacuuming. They rarely survive more than one or two days indoors, due to lack of moisture.

Pesticide sprays, granules and baits can help control pillbugs outdoors. Permethrin insecticide is more effective than acephate (Orthene) or carbaryl (Sevin) sprays. Other pyrethroid insecticides, such as cyfluthrin, esfenvalerate or lambda-cyhalothrin should also provide control. Always follow label directions, especially when applying slug and snail baits, as these products can be harmful to children and pets if misapplied.

For more information

More information about household and garden insects is available through your county Extension agent. For more information about pyrethroid and other types of insecticides, see [email protected] ent-4002, Understanding Common House & Garden Insecticides. For more information on pillbugs, see the article by Gary Raham (The American Biology Teacher 48(1): 9-16, January 1986) and Sue Hubbell’s book, Waiting for Aphrodite: Journeys into the Time Before Bones , 1999. Both give some interesting insights into pillbugs, as well as ideas for possible science fair projects.

What is this insect found in a shower? - Biology

(Rhabditida: Steinernematidae & Heterorhabditidae)

By David I. Shapiro-Ilan, USDA-ARS, SEFTNRL, Byron, GA &
Randy Gaugler, Department of Entomology, Rutgers University, New Brunswick New Jersey

Nematodes are simple roundworms. Colorless, unsegmented, and lacking appendages, nematodes may be free-living, predaceous, or parasitic. Many of the parasitic species cause important diseases of plants, animals, and humans. Other species are beneficial in attacking insect pests, mostly sterilizing or otherwise debilitating their hosts. A very few cause insect death but these species tend to be difficult (e.g., tetradomatids) or expensive (e.g. mermithids) to mass produce, have narrow host specificity against pests of minor economic importance, possess modest virulence (e.g., sphaeruliids) or are otherwise poorly suited to exploit for pest control purposes. The only insect-parasitic nematodes possessing an optimal balance of biological control attributes are entomopathogenic or insecticidal nematodes in the genera Steinernema and Heterorhabditis. These multi-cellular metazoans occupy a biocontrol middle ground between microbial pathogens and predators/parasitoids, and are invariably lumped with pathogens, presumably because of their symbiotic relationship with bacteria.

Entomopathogenic nematodes are extraordinarily lethal to many important insect pests, yet are safe for plants and animals. This high degree of safety means that unlike chemicals, or even Bacillus thuringiensis, nematode applications do not require masks or other safety equipment and re-entry time, residues, groundwater contamination, chemical trespass, and pollinators are not issues. Most biologicals require days or weeks to kill, yet nematodes, working with their symbiotic bacteria, can kill insects within 24-48 hours. Dozens of different insect pests are susceptible to infection, yet no adverse effects have been shown against beneficial insects or other nontargets in field studies (Georgis et al., 1991 Akhurst and Smith, 2002). Nematodes are amenable to mass production and do not require specialized application equipment as they are compatible with standard agrochemical equipment, including various sprayers (e.g., backpack, pressurized, mist, electrostatic, fan, and aerial) and irrigation systems.

Hundreds of researchers representing more than forty countries are working to develop nematodes as biological insecticides. Nematodes have been marketed on every continent except Antarctica for control of insect pests in high-value horticulture, agriculture, and home and garden niche markets.

Steinernematids and heterorhabditids have similar life histories. The non-feeding, developmentally arrested infective juvenile seeks out insect hosts and initiates infections. When a host has been located, the nematodes penetrate into the insect body cavity, usually via natural body openings (mouth, anus, spiracles) or areas of thin cuticle. Once in the body cavity, a symbiotic bacterium (Xenorhabdus for steinernematids, Photorhabdus for heterorhabditids) is released from the nematode gut, which multiplies rapidly and causes rapid insect death. The nematodes feed upon the bacteria and liquefying host, and mature into adults. Steinernematid infective juveniles may become males or females, where as heterorhabditids develop into self-fertilizing hermaphrodites although subsequent generations within a host produce males and females as well.

The life cycle is completed in a few days, and hundreds of thousands of new infective juveniles emerge in search of fresh hosts. Thus, entomopathogenic nematodes are a nematode-bacterium complex. The nematode may appear as little more than a biological syringe for its bacterial partner, yet the relationship between these organisms is one of classic mutualism. Nematode growth and reproduction depend upon conditions established in the host cadaver by the bacterium. The bacterium further contributes anti-immune proteins to assist the nematode in overcoming host defenses, and anti-microbials that suppress colonization of the cadaver by competing secondary invaders. Conversely, the bacterium lacks invasive powers and is dependent upon the nematode to locate and penetrate suitable hosts.

Production and Storage Technology

Entomopathogenic nematodes are mass produced for use as biopesticides using in vivo or in vitro methods (Shapiro-Ilan and Gaugler 2002). In vivo production (culture in live insect hosts) requires a low level of technology, has low startup costs, and resulting nematode quality is generally high, yet cost efficiency is low. The approach can be considered ideal for small markets. In vivo production may be improved through innovations in mechanization and streamlining. A novel alternative approach to in vivo methodology is production and application of nematodes in infected host cadavers the cadavers (with nematodes developing inside) are distributed directly to the target site and pest suppression is subsequently achieved by the infective juveniles that emerge. In vitro solid culture, i.e., growing the nematodes on crumbled polyurethane foam, offers an intermediate level of technology and costs. In vitro liquid culture is the most cost- efficient production method but requires the largest startup capital. Liquid culture may be improved through progress in media development, nematode recovery, and bioreactor design. A variety of formulations have been developed to facilitate nematode storage and application including activated charcoal, alginate and polyacrylamide gels, baits, clay, paste, peat, polyurethane sponge, vermiculite, and water-dispersible granules. Depending on the formulation and nematode species, successful storage under refrigeration ranges from one to seven months. Optimum storage temperature for formulated nematodes varies according to species generally, steinernematids tend to store best at 4-8 °C whereas heterorhabditids persist better at 10-15 °C.

Relative Effectiveness and Application Parameters

Growers will not adopt biological agents that do not provide efficacy comparable with standard chemical insecticides. Technological advances in nematode production, formulation, quality control, application timing and delivery, and particularly in selecting optimal target habitats and target pests, have narrowed the efficacy gap between chemical and nematode agents. Nematodes have consequently demonstrated efficacy in a number of agricultural and horticultural market segments.

Entomopathogenic nematodes are remarkably versatile in being useful against many soil and cryptic insect pests in diverse cropping systems, yet are clearly underutilized. Like other biological control agents, nematodes are constrained by being living organisms that require specific conditions to be effective. Thus, desiccation or ultraviolet light rapidly inactivates insecticidal nematodes chemical insecticides are less constrained. Similarly, nematodes are effective within a narrower temperature range (generally between 20 °C and 30 °C) than chemicals, and are more impacted by suboptimal soil type, thatch depth, and irrigation frequency (Georgis and Gaugler, 1991 Shapiro-Ilan et al., 2006). Nematode-based insecticides may be inactivated if stored in hot vehicles, cannot be left in spray tanks for long periods, and are incompatible with several agricultural chemicals. Chemicals also have problems (e.g., mammalian toxicity, resistance, groundwater pollution, etc.) but a large knowledge base has been developed to support their use. Accelerated implementation of nematodes into IPM systems will require users to be more knowledgeable about how to use them effectively.

Therefore, based on the nematodes&rsquo biology, applications should be made in a manner that avoids direct sunlight, e.g., early morning or evening applications are often preferable. Soil in the treated area should be kept moist for at least two weeks after applications. Application to aboveground target areas is difficult due to the nematode&rsquos sensitivity to desiccation and UV radiation however, some success against certain above-ground targets has been achieved and recently approaches have been enhanced by improved formulations (e.g., Shapiro-Ilan et al., 2010). In all cases, the nematodes must be applied at a rate that is sufficient to kill the target pest generally, 250,000 infective juveniles per m2 of treated area is required (though in some cases an increased or slightly decreased rate may be suitable) (Shapiro-Ilan et al., 2002). Additionally, it is important to match the appropriate nematode species to the particular pest that is being targeted (see the table below for species effectiveness).

Nematodes are formulated and applied as infective juveniles, the only free-living and therefore environmentally tolerant stage. Infective juveniles range from 0.4 to 1.5 mm in length and can be observed with a hand lens or microscope after separation from formulation materials. Disturbed nematodes move actively, however sedentary ambusher species (e.g. Steinernema carpocapsae, S. scapterisci) in water soon revert to a characteristic "J"-shaped resting position. Low temperature or oxygen levels will inhibit movement of even active cruiser species (e.g., S. glaseri, Heterorhabditis bacteriophora). In short, lack of movement is not always a sign of mortality nematodes may have to be stimulated (e.g., probes, acetic acid, gentle heat) to move before assessing viability. Good quality nematodes tend to possess high lipid levels that provide a dense appearance, whereas nearly transparent nematodes are often active but possess low powers of infection.

Insects killed by most steinernematid nematodes become brown or tan, whereas insects killed by heterorhabditids become red and the tissues assume a gummy consistency. A dim luminescence given off by insects freshly killed by heterorhabditids is a foolproof diagnostic for this genus (the symbiotic bacteria provide the luminescence). Black cadavers with associated putrefaction indicate that the host was not killed by entomopathogenic species. Nematodes found within such cadavers tend to be free-living soil saprophages.

Steinernematid and heterorhabditid nematodes are exclusively soil organisms. They are ubiquitous, having been isolated from every inhabited continent from a wide range of ecologically diverse soil habitats including cultivated fields, forests, grasslands, deserts, and even ocean beaches. When surveyed, entomopathogenic nematodes are recovered from 2% to 45% of sites sampled (Hominick, 2002).

Because the symbiotic bacterium kills insects so quickly, there is no intimate host-parasite relationship as is characteristic for other insect-parasitic nematodes. Consequently, entomopathogenic nematodes are lethal to an extraordinarily broad range of insect pests in the laboratory. Field host range is considerably more restricted, with some species being quite narrow in host specificity. Nonetheless, when considered as a group of nearly 80 species, entomopathogenic nematodes are useful against a large number of insect pests (Grewal et al., 2005). Additionally, entomopathogenic nematodes have been marketed for control of certain plant parasitic nematodes, though efficacy has been variable depending on species (Lewis and Grewal, 2005). A list of many of the insect pests that are commercially targeted with entomopathogenic nematodes is provided in the table below. As field research progresses and improved insect-nematode matches are made, this list is certain to expand.


Common name
Scientific name
Crop(s) targeted
Nematodes *
Artichoke plume moth Platyptilia carduidactyla Artichoke Sc
Armyworms Lepidoptera: Noctuidae Vegetables Sc, Sf, Sr
Banana moth Opogona sachari Ornamentals Hb, Sc
Banana root borer Cosmopolites sordidus Banana Sc, Sf, Sg
Billbug Sphenophorus spp. (Coleoptera: Curculionidae) Turf Hb,Sc
Black cutworm Agrotis ipsilon Turf, vegetables Sc
Black vine weevil Otiorhynchus sulcatus Berries, ornamentals Hb, Hd, Hm, Hmeg, Sc, Sg
Borers Synanthedon spp. and other sesiids Fruit trees & ornamentals Hb, Sc, Sf
Cat flea Ctenocephalides felis Home yard, turf Sc
Citrus root weevil Pachnaeus spp. (Coleoptera: Curculionidae Citrus, ornamentals Sr, Hb
Codling moth Cydia pomonella Pome fruit Sc, Sf
Corn earworm Helicoverpa zea Vegetables Sc, Sf, Sr
Corn rootworm Diabrotica spp. Vegetables Hb, Sc
Cranberry girdler Chrysoteuchia topiaria Cranberries Sc
Crane fly Diptera: Tipulidae Turf Sc
Diaprepes root weevil Diaprepes abbreviatus Citrus, ornamentals Hb, Sr
Fungus gnats Diptera: Sciaridae Mushrooms, greenhouse Sf, Hb
Grape root borer Vitacea polistiformis Grapes Hz, Hb
Iris borer Macronoctua onusta Iris Hb, Sc
Large pine weevil Hylobius albietis Forest plantings Hd, Sc
Leafminers Liriomyza spp. (Diptera: Agromyzidae) Vegetables, ornamentals Sc, Sf
Mole crickets Scapteriscus spp. Turf Sc, Sr, Scap
Navel orangeworm Amyelois transitella Nut and fruit trees Sc
Plum curculio Conotrachelus nenuphar Fruit trees Sr
Scarab grubs** Coleoptera: Scarabaeidae Turf, ornamentals Hb, Sc, Sg, Ss, Hz
Shore flies Scatella spp. Ornamentals Sc, Sf
Strawberry root weevil Otiorhynchus ovatus Berries Hm
Small hive beetle Aethina tumida Bee hives Yes (Hi, Sr)
Sweetpotato weevil Cylas formicarius Sweet potato Hb, Sc, Sf

* At least one scientific study reported 75% suppression of these pests using the nematodes indicated in field or greenhouse experiments. Subsequent/other studies may reveal other nematodes that are virulent to these pests. Nematodes species used are abbreviated as follows: Hb=Heterorhabditis bacteriophora, Hd = H. downesi, Hi = H. indica, Hm= H. marelata, Hmeg = H. megidis, Hz = H. zealandica, Sc=Steinernema carpocapsae, Sf=S. feltiae, Sg=S. glaseri, Sk = S. kushidai, Sr=S. riobrave, Sscap=S. scapterisci, Ss = S. scarabaei.
** Efficacy of various pest species within this group varies among nematode species.

Characteristics of Some Commercialized Species

Steinernema carpocapsae: This species is the most studied of all entomopathogenic nematodes. Important attributes include ease of mass production and ability to formulate in a partially desiccated state that provides several months of room-temperature shelf-life. S. carpocapsae is particularly effective against lepidopterous larvae, including various webworms, cutworms, armyworms, girdlers, some weevils, and wood-borers. This species is a classic sit-and-wait or "ambush" forager, standing on its tail in an upright position near the soil surface and attaching to passing hosts. Consequently, S. carpocapsae is especially effective when applied against highly mobile surface-adapted insects (though some below-ground insects are also controlled by this nematode). S. carpocapsae is also highly responsive to carbon dioxide once a host has been contacted, thus the spiracles are a key portal of host entry. It is most effective at temperatures ranging from 22 to 28°C.

Steinernema feltiae: S. feltiae is especially effective against immature dipterous insects, including mushroom flies, fungus gnats, and tipulids as well some lepidopterous larvae. This nematode is unique in maintaining infectivity at soil temperatures as low as 10°C. S. feltiae has an intermediate foraging strategy between the ambush and cruiser type.

Steinernema glaseri: One of the largest entomopathogenic nematode species at twice the length but eight times the volume of S. carpocapsae infective juveniles, S. glaseri is especially effective against coleopterous larvae, particularly scarabs. This species is a cruise forager, neither nictating nor attaching well to passing hosts, but highly mobile and responsive to long-range host volatiles. Thus, this nematode is best adapted to parasitize hosts possessing low mobility and residing within the soil profile. Field trials, particularly in Japan, have shown that S. glaseri can provide control of several scarab species. Large size, however, reduces yield, making this species significantly more expensive to produce than other species. A tendency to occasionally "lose" its bacterial symbiote is bothersome. Moreover, the highly active and robust infective juveniles are difficult to contain within formulations that rely on partial nematode dehydration. In short, additional technological advances are needed before this nematode is likely to see substantial use.

Steinernema kushidai: Only isolated so far from Japan and only known to parasitize scarab larvae, S. kushidai has been commercialized and marketed primarily in Asia.

Steinernema riobrave: This novel and highly pathogenic species was originally isolated from the Rio Grande Valley of Texas, but has since been also been isolated in other areas, e.g., in the southwestern USA. Its effective host range runs across multiple insect orders. This versatility is likely due in part to its ability to exploit aspects of both ambusher and cruiser means of finding hosts. Trials have demonstrated its effectiveness against corn earworm, mole crickets, and plum curculio. Steinernema riobrave has also been highly effective in suppressing citrus root weevils (e.g., Diaprepes abbreviates and Pachnaeus species). This nematode is active across a range of temperatures it is effective at killing insects at soil temperatures above 35°C, and can also infect at 15 °C. Persistence is excellent even under semi-arid conditions, a feature no doubt enhanced by the uniquely high lipid levels found in infective juveniles. Its small size provides high yields whether using in vivo (up to 375,000 infective juveniles per wax moth larvae) or in vitro methods.

Steinernema scapterisci: The only entomopathogenic nematode to be used in a classical biological control program, S. scapterisci was isolated from Uruguay and first released in Florida in 1985 to suppress an introduced pest, mole crickets. The nematode become established and presently contributes to control. Steinernema scapterisci is highly specific to mole crickets. Its ambusher approach to finding insects is ideally suited to the turfgrass tunneling habits of its host. Commercially available since 1993, this nematode is also sold as a biological insecticide, where its excellent ability to persist and provide long-term control contributes to overall efficacy.

Heterorhabditis bacteriophora: Among the most economically important entomopathogenic nematodes, H. bacteriophora possesses considerable versatility, attacking lepidopterous and coleopterous insect larvae, among other insects. This cruiser species appears quite useful against root weevils, particularly black vine weevil where it has provided consistently excellent results in containerized soil. A warm temperature nematode, H. bacteriophora shows reduced efficacy when soil drops below 20°C.

Heterorhabditis indica: First discovered in India, this nematode is now known to be ubiquitous. Heterorhabditis indica is considered to be a heat tolerant nematode (infecting insects at 30 °C or higher). The nematode produces high yields in vivo and in vitro, but shelf life is generally shorter than most other nematode species.

Heterorhabditis megidis:
First isolated in Ohio, this nematode is commercially available and marketed especially in western Europe for control of black vine weevil and various other soil insects. Heterorhabditis megidis is considered to be a cold tolerant nematode because it can effectively infect insects at temperatures below 15 °C.

Conservation strategies are poorly developed and largely limited to avoiding applications onto sites where the nematodes are ill-adapted for example, where immediate mortality is likely (e.g., exposed foliage) or where they are completely ineffective (e.g., aquatic habitats) (Lewis et al., 1998). Minimizing deleterious effects of the aboveground environment with a post-application rinse that washes infective juveniles into the soil is also a useful approach to increasing persistence and efficacy. Native populations are highly prevalent, but, other than scattered reports of epizootics, their impact on host populations is generally not well documented (Stuart et al., 2006). This is largely attributable to the cryptic nature of soil insects. Consequently, research and guidelines for conserving native entomopathogenic nematodes are in need of advancement.

Infective juveniles are compatible with most but not all agricultural chemicals under field conditions. Compatibility has been tested with well over 100 different chemical pesticides. Entomopathogenic nematodes are compatible (e.g., may be tank-mixed) with most chemical herbicides and fungicides as well as many insecticides (such as bacterial or fungal products) (Koppenhöfer and Grewal, 2005). In fact, in some cases, combinations of chemical agents with nematodes results in synergistic levels of insect mortality. Some chemicals to be used with care or avoided include aldicarb, carbofuran, diazinon, dodine, methomyl, and various nematicides. However, specific interactions can vary based on the nematode and host species and application rates. Furthermore, even when a specific chemical pesticide is not deemed compatible, use of both agents (chemical and nematode) can be implemented by waiting an appropriate interval between applications (e.g., 1 &ndash 2 weeks). Prior to use, compatibility and potential for tank-mixing should be based on manufacturer recommendations. Similarly, entomopathogenic nematodes are also compatible with many though not all biopesticides (Koppenhöfer and Grewal, 2005) interactions range from antagonism to additivity or synergy depending on the specific combination of control agents, target pest, and rates and timing of application. Nematodes are generally compatible with chemical fertilizers as well as composted manure though fresh manure can be detrimental.

Of the nearly eighty steinernematid and heterorhabditid nematodes identified to date, at least twelve species have been commercialized. A list of some nematode producers and suppliers is provided below the list emphasizes U.S. suppliers. Comparison-shopping is recommended as prices vary greatly among suppliers. Additionally, caution is again advised with regard to application rates. One billion nematodes per acre (250,000 per m2) is the rule-of-thumb against most soil insects (containerized and greenhouse soils tend to be treated at higher rates). A final caveat is that, just as one must select the appropriate insecticide to control a target insect, so must one choose the appropriate nematode species or strain. Ask suppliers about field tests supporting their recommended matching of insect target and nematode.


P.O. Box 4247 CRB
Tucson, AZ 85738-1247.
Telephone: 520-825-9785,
FAX: 520-825-2038

Springtown Road, P.O. Box 177
Willow Hill, PA 17271

134 West Drive
Lodi, Ohio 44254.
Telephone: 800/321-5656,
FAX: 330-302-4204
FAX: 330-722-2616

Klausdorfer Str. 28-36
24223 Schwentinental
FAX: +49-4307-8295-14

5100 Schenley Place
Lawrenceburg, IN 47025.
Telephone: 513-354-1482

128 Intervale Road
Burlington, VT 05401
Telephone: 888-833-1412,

2725A Hwy 32 West
Chico CA 95973.
Telephone: 530-895-8301,
FAX: 530-895-8317

93 Priest Road
Nottingham, NH 03290-6204
Telephone: 603-942-8925
FAX 603-942-8932

3244 Hwy. 116 North
Sebastopol, CA 95472
FAX: 707-823-1734

Veilingweg 17, P.O. Box 155 2650
AD Berkel en Rodenrijs
The Netherlands

Koppert (USA)28465
Beverly Road
Romulus, Michigan 48174
Telephone:1-800- 928-8827
FAX: 734 641 3799

P.O. Box 886
Bayfield, CO 81122.
Telephone: 800-526-4075
FAX: 970-259-3857.

606 Ball Street or
P.O. Box 1546,
Perry, GA 31069
Telephone: 478-988-9412,
FAX: 478-988-9413.

7028 W. Waters Ave.,
Suite #264
Tampa, FL 33634-2292
Telephone: 866-215-2230.

* Mention of a proprietary product name does not imply USDA&rsquos approval of the product to the exclusion of others that may be suitable.

Akhurst, R. and K. Smith. 2002. Regulation and safety. In: Gaugler, R. (Ed.), Entomopathogenic Nematology. CABI, New York, NY, pp. 311-332.

Georgis, R. and R. Gaugler. 1991. Predictability in biological control using entomopathogenic nematodes. Journal of Economic Entomology. [Forum] 84: 713-20.

Georgis, R., H. Kaya, and R. Gaugler. 1991. Effect of steinernematid and heterorhabditid nematodes on nontarget arthropods. Environmental Entomology 20: 815-22.

Grewal, P. S., R-U, Ehlers, and D. I. Shapiro-Ilan. 2005. Nematodes as Biocontrol Agents. CABI, New York, NY.

Hominick, W. M. 2002. Biogeography. In: Gaugler, R. (Ed.), Entomopathogenic Nematology. CABI, New York, NY, pp. 115-143.

Koppenhöfer, A. M. and P. S. Grewal. 2005. Compatibility and interactions with agrochemicals and other biocontrol agents. In: Nematodes as Biocontrol Agents. CABI, New York, NY, pp. 363-381.

Lewis, E., J. Campbell, and R. Gaugler. 1998. A conservation approach to using entomopathogenic nematodes in turf and landscapes. In: Barbosa, P. (Ed.), Perspectives on the Conservation of Natural Enemies of Pest Species, Academic Press, New York, pp. 235-254.

Lewis, E.E. and P. S. Grewal. 2005. Interactions with plant parasitic nematodes. In: Grewal, P.S., Ehlers, R.-U., and Shapiro-Ilan, D.I. (Eds.), Nematodes as Biocontrol Agents. CABI, New York, NY., pp. 349-362.
Shapiro-Ilan D. I. and R. Gaugler. 2002. Production technology for entomopathogenic nematodes and their bacterial symbionts. Journal of Industrial Microbiology and Biotechnology 28: 137-146.

Shapiro-Ilan, D. I., D. H. Gouge, and A. M. Koppenhöfer. 2002. Factors affecting commercial success: case studies in cotton, turf and citrus. In: Gaugler, R. (Ed.), Entomopathogenic Nematology. CABI, New York, NY, pp. 333-356.

Shapiro-Ilan, D.I., D. H. Gouge, S. J. Piggott, and J. Patterson Fife. 2006. Application technology and environmental considerations for use of entomopathogenic nematodes in biological control. Biological Control 38: 124-133.

Shapiro-Ilan, D. I., T. E. Cottrell, R. F. Mizell, D. L. Horton, B. Behle, and C. Dunlap. 2010. Efficacy of Steinernema carpocapsae for control of the lesser peachtree borer, Synanthedon pictipes: Improved aboveground suppression with a novel gel application. Biological Control 54, 23&ndash28.

Mason Bee

Most mason bees are smaller than honey bees, but some are about the same size as honey bees or slightly larger. They have stout bodies, and many species are metallic green or bluish in color. Mason bees are common in the western United States, especially in forested regions, but they are also found in many other parts of the northern hemisphere. About 140 species of mason bees are found in North America out of about 200 species worldwide. These bees have a sting but do not attack defensively unless handled.

The orchard mason bee, or blue orchard bee, is a metallic blue-black species about 13 mm (0.5 in) long. This bee, native to North America, specializes in collecting pollen from the flowers of fruit trees. In some parts of the United States, the bees are cultivated to pollinate orchard crops, especially apples. This bee nests in holes in wood and the females prefer to make nests close to each other in aggregations. These traits are used to concentrate enough bees in an area for commercial pollination. Blocks of wood with holes drilled in them attract nesting bees. These nest blocks are hung from trees or are placed in shelters for protection from the weather.

Orchard mason bees mate in the spring. The females then begin to collect pollen and lay eggs. Larval bees feed for several weeks inside their closed cells. They pupate in late summer and spend the autumn and winter as adults inside their pupal cocoons in the nest. They emerge from the cocoons in the spring, coinciding with flowering of many orchard crops. The new generation of bees then begins the cycle over again.

Orchard mason bees are very effective pollinators. Two or three females can pollinate the equivalent of a mature apple tree in one season. They fly in cool or rainy weather and can supplement or replace honey bees as commercial pollinators in some situations.

Other mason bees are also used for pollination. Another North American species, the blue blueberry bee, is used as a pollinator for blueberry plants. The Japanese hornfaced bee is native to Japan and has been used for apple pollination there for more than 50 years. One female can pollinate over 2000 apple flowers per day. The Spanish hornfaced bee is used similarly in Spain for pollinating the flowers of almond trees.

Scientific classification: Mason bees comprise the genus Osmia in the leafcutter bee family Megachilidae, order Hymenoptera. The orchard mason bee is Osmia lignaria, the Japanese hornfaced bee is Osmia cornuta, and the Spanish hornfaced bee is Osmia cornifrons the blue blueberry bee is Osmia ribifloris.

What Lives in Your House (Besides You)

A treehopper ponders the big wide world from the inside of a house. Photo by Kalliopi Monoyios (Sci Am blogger for Symbiartic!) Used with permission.

Chances are you have never heard of a gall midge or a book louse. But odds are also good, at least if you live on the mid-Atlantic seaboard, that they know about you. That&rsquos because you&rsquore roommates. Nearly 100% of 50 houses surveyed in and around Raleigh, North Carolina, contained these insects.

That was the surprising conclusion of a new study by entomologists at North Carolina State University -- including Sci Am guest blogger Rob Dunn -- that aimed to document the insects, spiders, and other arthropods of a random sample of homes.

The scientists sought to probe a largely uninvestigated yet very personal frontier: the tiny animals that dwell with us. Although scientists have intensively studied pests, almost nothing has been done to survey everyone else -- and everyone else turns out to be the silent majority. Unnoticed and overlooked by humans, we don&rsquot know if these other animals are helping, hurting, or having no impact whatsoever on us, nor do we even know who they are and how many of them there are.

To remedy that problem, the scientists randomly selected 50 free-standing homes from a list of volunteers who had filled out a survey about their residence and its residents. All 50 dwellings were within a 30-mile radius of the center of Raleigh, and the homes ranged in age from seven to 94 years old. Entomologists combed through all rooms except attics and crawl spaces for reasons of safety, only a two meter radius from the entrance of such spaces was examined. Oddly, the safety reasons cited were heat and confinement, not the presence of an army of hella scary creepy-crawlies.

Stand back, ma&rsquoam. I&rsquom an entomologist.

The team collected every visible insect inside each room with forceps, vacuums, or nets, looking under and behind furniture, around baseboards, ceilings, and on shelves and any openly accessible surface. They did not, however, open drawers, cabinets, or look inside walls or under heavy furniture. They did pluck the victims from spider webs. All confiscated insects were promptly soused in 95% ethanol.

After scouring the literature to identify all their specimens to family, they compiled their data in tables. Most people like to think they are living in a relatively sterile, and at least mostly animal-free (small pets and children excepted) environment. However, the data contained in these tables belie those beliefs.

First, the prevalence of insects in homes was surprising, the authors said. Nearly every room contained insect occupants. And the diversity was enormous. All together, the scientists found at least 579 different species. Each home contained an average of 93.14 physically distinguishable species from 61.84 arthropod families, ranging from 32-211 species and 24-128 families. Given the somewhat superficial approach to insect sampling (drawers, cabinets, wall-interiors, and attics being well-known insect haunts), the true number of species in each house was likely higher. Bigger homes generally had more species, an unsurprising correlation.

Given that this survey was limited to homes in a 30-mile radius of Raleigh, North Carolina, the true diversity of insects found in homes in the United States, not to mention the globe, must be staggering.

Because so much past research on insects in homes has centered on structure- or health-threatening pests, the authors expected them to be among the most commonly encountered arthropods. Instead, they found a relative lack. Pests were found cockroaches were sighted in 82% of homes, though most were non-pest species (the pestiferous German and American cockroaches were found in only 6% of homes each). Scavenging carpet beetles were found in 100% of homes in some instances, dog kibble became carpet beetle kibble, along with dead insects and nail clippings, but the larvae of these pests usually eat natural fibers and feathers found in clothing, upholstery, or carpet, dust, and lint.

Termites were found in 28% of homes, clothes moths in 60%, fleas in 10%, and mosquitoes in 82%. No doubt to homeowners&rsquo great relief, bed bugs were not found anywhere. Dust mites were found in 76% of homes, which may not seem surprising until you think about how ubiquitous they are considered to be and what other insects were found in 100% or near 100% of homes: springtails in 88%, book lice in 98%, gall midges in 100%, dark-winged fungus gnats in 96% (by contrast, fruit flies were only in 66%), and ants and cobweb spiders in 100% (okay, last two maybe not a surprise).

The most frequently collected arthropod families from homes in this study. (A) cobweb spiders (100% of homes) (B) carpet beetles (100%) (C) gall midges (100%) (D) ants (100%) (E) book lice (98%) (F) dark0-winged fungus gnats (96%) (G) cellar spiders (84%) (H) weevils (82%) (I) scuttle flies (82%) (J) scuttle flies (82%) (K) leafhoppers (82%) (L) non-biting midges (80%). Fig. 4 from Bertone et al. 2016. Photos by Matthew A. Bertone.

By now you may be wondering, all right, I&rsquove made it this far. Are you ever going to tell me what a gall midge or a book louse is?

Gall midges are tiny, delicate flies &ndash usually only two or three millimeters long, but often smaller than a millimeter. Their home is on or near plants. They have long antennae and, interestingly, hairy wings. Perhaps all the hairs act as drag strips that help the elfin insects float on the breeze.

By Unknown -, Public Domain

As larvae, gall midges suck plant juices and cause tumors called galls to form on their hosts. Some gall midges prey on or parasitize other crop pests like thrips, whiteflies, aphids, spider mites, or scale insects. Despite the fact they were found inside each and every home in this study, a recent compilation of city-dwelling insects and arachnids failed to list them in a roster 2,000 species long.

Legs 'till Tuesday: a gall midge. By Alvesgaspar - Own work, CC BY-SA 3.0

What were they doing in all these houses? We&rsquoll get back to that in a minute.

Book lice are close relatives of the body and hair lice that have plagued humans for millennia. They are tiny &ndash less than a sixteenth of an inch long &ndash and wingless. Also kind of cute. It's those little beady eyes.

A book louse. Fig. 4E from Bertone et al. 2016. Photo by Matthew A. Bertone. By MAF Plant Health & Environment Laboratory -, CC BY 3.0 au

However, instead of sucking blood or munching skin, book lice eat the mold that grows on household detritus, wallpaper paste, potted plant soil, or stored grains. As you can imagine, this is an insect that thrives in the same humid climates that yield soggy cereal and moldy books -- hence the name.

In contrast to these common but obscure insects, dust mites, allergens of great fame, were present in about three-quarters of dwellings. As expected, more mites tended to be found in carpets (carpets trap food and moisture, and shield and insulate mites), but the most mites of all were found in a wood-floored home, proving hardwood is no guarantee. Humidity and vacuuming habits may play a role, the authors suggested, or gaps in floorboards could act as dust mite nature preserves. For those of us without dust mite allergies, however, dust mites are likely the best, lowest maintenance pets we&rsquoll ever have. They&rsquore so quiet you&rsquoll never even know they&rsquore there, and you already clean up after them every time you vacuum or sweep. So what if you need a microscope to play with your pets?

Many more surprising denizens made cameos in the survey, including earwigs, jumping bristletails, death watch beetles, assassin bugs, silken fungus beetles, fireflies, blow flies, phantom midges, freeloader flies (near the couch?), fungus gnats, goblin spiders, stone centipedes, and woodlice. Parasitoid wasps that attack the insects found in homes were also found, including one that attacks blattid cockroach egg cases. That one was commonly found in homes along with its host, and must be a welcome guest were its human companions to know of it.

Many of the unexpected species seemed to have flown, wandered, or drifted in from outdoors and either become trapped or expired before they could escape. In effect, houses may act like passive samplers of the &ldquoair plankton&rdquo(love!) &ndash a menagerie of tiny semi-drifting airborne animals like gall midges. In this way many of the animals found in homes may be more a reflection of the outdoors than the indoors.

For instance, leafhoppers, like many plant pests, are more or less botanical mosquitoes they make a living piercing and sucking the juices from plants, and as such must have little interest in the interiors of all but the leafiest homes. Yet they were found in 82% of homes in this survey. On the other hand, there was a surprising lack of moths and butterflies given their abundance out of doors. They made up only 2% of the average diversity in a room.

[Some species were surprising because they are rare anywhere, ant-loving crickets being but one example found in homes infested with ants.

By Gunther Tschuch - Own work, CC BY-SA 2.5

Another rare surprise was primitive beetles from the order Archostemata, which resemble Earth's first beetles.

One house contained a "rarely-seen" larval beaded lacewing, a parasite of termite nests. They emit a chemical that paralyzes termites, allowing them to dine upon them.

Adult beaded lacewing -- a thing of weird beauty. By Lucinda Gibson, Museum Victoria -, CC BY 3.0 au

A few other lurid curiosities: flesh flies emerged from a rodent killed by a house cat in one home, while centipedes that prey on other insects, and spitting spiders &ndash which can shoot sticky silk-laced venom a centimeter away to grab prey &ndash were found in others.

Our civilized habits have also reduced some insects&rsquo abundance while boosting others&rsquo. The advent of indoor plumbing has reduced (but not eliminated!) dung beetles in our homes. But it has also provided new horizons for drain-dwelling moth flies, who are likely more common now. House flies, German cockroaches, and fruit flies have piggybacked on our spread to launch themselves to worldwide success. The German cockroach doesn&rsquot even have wild populations anymore.

Some of the most common insects in our homes gained that status because they&rsquove been rooming with us since we lived in caves &ndash literally. Of the pest species found in this study, many have been recovered from archaeological sites: grain weevils carpet, grain, cigarette and drugstore beetles and house flies. Bed bugs evolved from a species found in bats, and were most likely picked up during our cave-dwelling days. Disease-transmitting kissing bugs may have been acquired the same way at least 26,000 years ago. One of the first known works of cave art depicts a camel cricket -- a group of insects found in 58% of the homes in this survey.

These insects have been with us a long time, and &ndash understandably -- appear to have no intention of dropping the acquaintance. Yet it appears, at least based on this limited sample, that the majority of insects found in our homes cause us no harm, headaches or unsightly welts, and probably didn&rsquot even want to end up there in the first place.

Bertone, Matthew A., Misha Leong, Keith M. Bayless, Tara LF Malow, Robert R. Dunn, and Michelle D. Trautwein. "Arthropods of the great indoors: characterizing diversity inside urban and suburban homes." PeerJ 4 (2016): e1582.

The views expressed are those of the author(s) and are not necessarily those of Scientific American.


Jennifer Frazer, an AAAS Science Journalism Award–winning science writer, authored The Artful Amoeba blog for Scientific American. She has degrees in biology, plant pathology and science writing.

What is this insect found in a shower? - Biology

KINGDOM: Animalia | PHYLUM: Arthropoda | CLASS: Insecta | ORDER :Diptera
FAMILIES: Muscidae (house flies), Calliphoridae (blow flies), Sarcophagidae (flesh flies), Tachinidae (tachinid flies)

Although it can be difficult to determine the family to which any one of these flies belongs, there are common characteristics exhibited by each family which are highlighted in the Common Types section below. These characteristics can aid in identification, but a microscope is essential for accurate identification. For technical details on identifying these flies, consult an accurate guide to insect taxonomy, such as:
Peterson Field Guide to Insects: Borror and White
Introduction To The Study of Insects: Borror, Triplehorn, and Johnson

Like all true flies (order Diptera), house flies and their relatives do not have chewing mouthparts. Instead, most flies in these 4 families have sponging mouthparts which are used to absorb liquids, such as nectar. Others, like stable flies, have piercing mouthparts used to suck blood. Like all insects, flies have 6 legs, 3 body regions (head, thorax, and abdomen) and 2 antennae.

Except for a few species whose larvae are parasitic on other insects, larvae from the "house fly" families are legless, soft-bodied maggots. Maggots are most commonly found in carrion or in animal waste.

Blow fly larva: a typical maggot (R. Bessin, 2000)

Their are many important pests in the families Muscidae, Calliphoridae, and Sarcophagidae. Flies in all of these families are a nuisance when they get into homes and when they occasionally spread diseases to humans. Read about the control of home-invading flies in our ENTFact:

The family Muscidae also contains Face Flies, Horn Flies, and Stable Flies. These flies harm livestock by causing irritation and spreading disease. Read about these livestock pests in the following ENTFacts:
Face Flies and Pink Eye
Horn Flies and Cattle

Some flies in the families Calliphoridae and Sarcophagidae are capable of infecting open wounds on humans and animals, a condition known as myiasis. Myiasis in humans is rare in the United States, but commonly occurs in tropical regions.

FAMILY: Muscidae | GENUS and SPECIES: Musca domestica
The House Fly, Musca domestica, pictured below, is one of the most common members of the family Muscidae, and one of the most common flies found in homes. It is about 1/4" long, and gray with 4 black stripes on the thorax. The house fly doesn't bite, unlike face flies, stable flies, and horn flies, which are also in the family Muscidae. Muscid flies and their maggots breed most commonly in manure.

Watch the video: Lethocerus patruelis. Λιθόκερος. (December 2021).