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Identify Huge Mystery Beetle

Identify Huge Mystery Beetle


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It is around 2 inches long, one inch wide, fat, hazel coloured with black specks and has short antennae. It's got a lot of cobwebs on its legs, since I found it in a corner in my house. It was found in North America.


It's a female Eastern Hercules beetle (Dynastes tityus). Unlike the male, the female doesn't have 'horns' as it doesn't need to fight in order to find a mating partner. It's the largest and heaviest beetle in North America. It belongs in Scarabaeidae or scarab beetles.

Source from BugGuide.com


Scientists reconstruct beetles from the Cretaceous

Micro-CT reconstruction of Mysteriomorphus pelevini Credit: D. Peris & R. Kundrata et al. /Scientific Reports

About a year ago, researchers found fossil specimens of beetles in an amber deposit in Myanmar, thereby describing a new beetle family that lived about 99 million years ago. However, the scientists had not been able to fully describe the morphology of the insects in the amber sample, which is why the beetles were subsequently given the mysterious name Mysteriomorphidae. An international research team led by the University of Bonn (Germany) and Palacky University (Czech Republic) has now examined four newly found specimens of the Mysteriomorphidae using computer tomography and has been able to reconstruct them. The results allow to draw conclusions about the evolution of the species during the Cretaceous period. The study has been published in the journal Scientific Reports.

Small creatures enclosed in amber can provide scientists with important information about past times, some of which date back many millions of years. In January 2019, the Spanish paleontologist Dr. David Peris, one of the two main authors of the study, collected several amber samples from the northern state of Kachin in Myanmar during a scientific trip to China and found beetle specimens from the same group as the Mysteriomorphidae.

Some of the newly found specimens showed a very good state of preservation—a good prerequisite for David Peris and his colleagues to carry out a virtual reconstruction of one of the beetles using computer tomography (CT scan). The technique used in paleontology allows researchers to study many small features of the fossils—even internal structures such as genitalia, if preserved.

While David Peris and his colleagues started to study and describe the morphology, i.e. the outer shape of the beetles, another research group also described the new family of Mysteriomorphidae by means of further specimens, that also came from the amber deposit in Myanmar. "However, the first study left some open questions about the classification of these fossils which had to be answered. We used the opportunity to pursue these questions with new technologies," explains David Peris, researcher now at the Institute for Geosciences and Meteorology at the University of Bonn.

"We used the morphology to better define the placement of the beetles and discovered that they were very closely related to Elateridae, a current family," explains Dr. Robin Kundrata from Palacky University, the second main author of the study and also an expert on this group of beetles. The scientists discovered important diagnostic characters that these beetle lineages share on mouthparts, thorax and abdomen.

Micro-CT reconstruction of Mysteriomorphus pelevini Credit: D. Peris & R. Kundrata et al./Scientific Reports

Analysis of the evolution of beetles

Apart from the morphology, the researchers also analyzed the evolutionary history of the beetles. Earlier models had suggested that the beetles had a low extinction rate throughout their long evolutionary history, even during the Cretaceous period. However, the researchers provided a list of fossil groups of beetles described from the Cretaceous amber findings that, as Mysteriomorphidae, are only known as fossils from that time and had not survived the end of the Cretaceous period.

Background: During the Cretaceous period, flowering plants spread all over the world, replacing the old plants in the changing environment. This distribution of plants was connected with new possibilities for many associated animals and also with the development of new living beings, for example pollinators of flowers. However, most previous theories had not described that the animal species that were previously well adapted to the old plants were under pressure to adapt to the new resources and possibly became extinct. "Our results support the hypothesis that beetles, but perhaps some other groups of insects, suffered a decrease in their diversity during the time of plant revolution," states David Peris.


Western conifer seed bug or brown marmorated stink bug?

Know your winter wanderers, because you could be mistaking the western conifer seed bug for an assassin bug, or worse, a brown marmorated stink bug.

Western conifer seed bug. Photo credit: Kurt Andreas

On sunny, winter days, it is not unusual to find a slow-moving insect or two indoors, on the windowsill or wall. Concern over who the visitor is has increased since last year when the brown marmorated stink bug entered our lives.

Before, the unwanted guest could be annoying, unwanted or repulsive. Now, people are in fear that the insect invader could also be very bad smelling. However, insect identification is a specific science and people often misidentify their home invader and become very distressed.

The happy news in all of this is that the suspected brown marmorated stink bug is probably a western conifer seed bug. The two insects vaguely resemble each other, but the innocuous western conifer seed bug gets the blame. It also gets blamed for being several different insects because of its body shape and coloration.

The western conifer seed bug is native of the United States. For a number of years, it was found in western states like California, Nevada and Oregon. Then, it began its slow migration across the country. It made its way to Michigan in the late 1980s and now is found as far east as Maine and New Brunswick, Canada. They recently have been found in Europe.

Being a true bug, it feeds with its piercing-sucking mouthparts on the gooey goodness inside of conifer seeds. The trees still produce cones, but there may be no viable seeds. For homeowners with trees in the landscape, this makes very little difference. Tree favorites are Douglas-fir, Scotch pine, white spruce, white and red pines.

The western conifer seed bug has a body length of 3/4 of an inch with a brownish top. There are checkers of black and white along the margins of the lower portion of the back. But the fastest way to identify the western conifer seed bug is to look at the lower hind leg. It is widened on each side of the leg and looks like a tiny leaf has been attached. Stink bugs and other look-alikes will just have a straight, cylindrical leg.

Adult brown marmorated stink bug with antennal and back markings circled. Photo credit: Rutgers University

Western conifer seed bugs spend the winter as adults and often find their way indoors where their loud buzzing sound when flying attracts attention. When crunched flat, they have a distinctive, musky, evergreen-turpentine odor. They have been called many things, but rarely by the correct name. They are often confused with squash bugs and assassin bugs, as well as the brown marmorated stink bug.

Squash bugs are a pest in many gardens where they destroy the leaves on zucchini, pumpkins and other members of the cucurbit family. Squash bug adults do not spend the winter as adults &ndash and no one will ever find them squeezing through a crack to come indoors any time of the year.

Several years ago, the papers carried articles about an assassin bug called the kissing bug. In the southeast part of the United States, this bug was blamed for transmitting African sleeping sickness. This insect also resembles the western conifer seed bug. There are assassin bugs in Michigan, but they do not carry any diseases.

To add insult to injury, the poor western conifer seed bug was tagged with the wrong name when it first appeared in Michigan. Entomologists first misidentified them as the leaf-footed pine seed bug. So it&rsquos been a long road to the recognition they so richly deserve. If there are evergreens with cones in the area, your mystery house guest may be the western conifer seed bug. So check that hind leg and relax.


Identify Huge Mystery Beetle - Biology

Large silk moth that is seen in Oregon from mid-July to August. The wing span can be an amazing 4-6 inches.

Prionus sp. "Prionus Beetles"

Large beetles that can be as large or larger than your thumb. As grubs these beetles feed on the roots of trees and shrubs. For more information on these beetles click here .

Monochamus sp. "Sawyer Beetles"

These native beetles are commonly mistaken for the Asian Longhorn Beetle (ALB). If you see one of these beetles and you are not sure if it is one of our native species or the ALB please submit it to the clinic for identification.

Buprestis aurulenta "The Golden Buprestid"

This showy wood boring insect is commonly found in flowers feeding on pollen. The beetle as an immature feeds under the bark of Ponderosa Pine and Douglas Fir. For more information visit the University of British Columbia Forest Pests Page .

Noctua pronuba "Large Yellow Underwing"

Although it is called the "Yellow Underwing" the underwings of this moth are typically a bright orange. The caterpillar of this moth is commonly known as a cutworm and is a common pest of tomato, potato, carrot, strawberry, grape, onions, spinach, mustard and grass.

Plodia interpunctella "Indian Meal Moth"


This pest is common in the household feeding on grains, pet food and dry cereal. This pest often goes unnoticed until the larvae have finished feeding and they wander off to pupate. The cocoons of this moth look like small cigar shaped spider egg sacs and are commonly found in corners and cracks.

Anthrenus verbasci "Variegated Carpet Beetle"

This is a common household pest that can feed on virtually anything including glue, paper, carpet fibers, stored grains, pet food, and pollen. The image on the right is the larva, pupa and the empty larval skin.

For more information on this pest and other dermestid beetles visit

Paracotalpa granicollis "Little Bears"

This species is commonly encountered in spring feeding on apple blossoms and the leaves of peach trees. Unfortunately the feeding habits of the larva is unknown, however some suggest that it may feed on the roots of native grasses.

Altica ambiens "Alder flea Beetle"

This pest feeds on the leaves of alder both as an adult and as an immature. The larvae skeletonize the leaves (eating the leaf tissue but leaving all of the veins, resulting in a lace-like appearance) while the adults are shot-hole feeders (eating out small to medium sized circles of leaf material). The adults overwinter at the base of the tree and emerge in the spring to feed and lay eggs. The larvae are present from late spring into late summer.

Centrodera spurca "Douglas Fir Borer"

This is a common long horned beetle in the west that feeds under the bark of Douglas-fir as a larva. The black spots on the sides of the beetle distinguish it from some of the other species that occur in Oregon .

Rosalia funebris "Banded Alder Borer"

This is a longhorn beetle that is commonly found throughout the west. The larvae feed in the trunks of dead of maple, alder, ash, sycamore, oak and willow. The adults emerge in mid-summer and are often found by home owners. Note that the light colored areas of this beetle can vary from bright white to a pale blue.

Lygus hesperus "Western Lygus Bug"

This is a common pest that is encountered during the summer. It feeds on a very wide array of plants including several of agricultural importance. The cream colored heart on the back of the insect is a good (but not absolute) identifier of this species.

Calligrapha multipunctata bigsbyana "Leaf beetle"

This beetle is a common pest that feeds on willow leaves as an adult and larva. This pest is common in the urban garden where it feeds on ornamental willows.

Gluphisia severa "Banded Pebble"

This moth is one of the first to emerge in spring and can be commonly found at lights starting in May. As a caterpillar it feeds on birch, cherry, willow and aspen, however it rarely causes enough damage to be noticed.

Phyllodesma americana "The American Lappet Moth"

This moth commonly feeds on oak, poplar, aspen, and willows. The caterpillar of this species is a solitary feeder that rarely causes enough damage to draw attention.

Ctenicera lobata "Click Beetle"

This is a pest of economic importance in British Columbia on cereal crops, grains, vegetables and grasses.


Insecticide exposure affects intergenerational patterns of DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata

Brevik, K., E. M. Bueno, S. McKay, S. D. Schoville, Y. H. Chen. https://doi.org/10.1111/eva.13153

Insecticide use is pervasive as a selective force in modern agroecosystems. Insect herbivores exposed to these insecticides have been able to rapidly evolve resistance to them, but how they are able to do so is poorly understood. One possible but largely unexplored explanation is that exposure to sublethal doses of insecticides may alter epigenetic patterns that are heritable.

For instance, epigenetic mechanisms, such as DNA methylation that modify gene expression without changing the underlying genetic code, may facilitate the emergence of resistant phenotypes in complex ways. We assessed the effects of sublethal insecticide exposure, with the neonicotinoid imidacloprid, on DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata, examining both global changes in DNA methylation and specific changes found within genes and transposable elements. We found that exposure to insecticide led to decreases in global DNA methylation for parent and F2 generations, and that many of the sites of changes in methylation are found within genes associated with insecticide resistance, such as cytochrome P450s, or within transposable elements. Exposure to sublethal doses of insecticide caused heritable changes in DNA methylation in an agricultural insect herbivore. Therefore, epigenetics may play a role in insecticide resistance, highlighting a fundamental mechanism of evolution while informing how we might better coexist with insect species in agroecosystems.


Adaptations - Who Is Going to Eat You?

Robber fly perched on a leaf waiting for the perfect prey. Image by Jeevan Jose via Wikimedia Commons. Click to enlarge and more information.

The long legs of tiger beetles help them run away from some enemies like robber flies. These flies swoop up from a perch to catch flying insects out of the air. As long as a tiger beetle can run along the ground, it can get away from the robber fly easily. But sometimes tiger beetles are chased by faster predators like lizards. Then the tiger beetle uses a secret weapon. They extend their hidden flight wings and take to the air. Most tiger beetles don’t fly more than 20 or 30 feet, but it is enough to get out of the way of a lizard. But what attacker waits to grab them in flight? You guessed it, the robber fly. To run or not to run? How does the poor tiger beetle know which decision to make?

If a beetle chooses not to run, they have a few other tricks they can try to avoid being eaten. Many tiger beetles have colors that match the ground on which they run. This camouflage makes it harder for some enemies to see them. Other tiger beetles have a pattern of stripes and blotches on their backs that make it hard for some enemies to recognize them as an insect. If tricks on the eye don't work, simply being the wrong size can have its benefits. Some tiger beetles are too big for spiders and robber flies to handle. The small size of other tiger beetles makes them too small of a meal for birds to waste energy chasing them.

Some tiger beetles make poisonous chemicals and display warning colors to other animals not to eat them. This Carolina Metallic tiger beetle, Tetracha carolina, produces cyanide that can make an animal sick or kill it if they decide to eat them.

For some tiger beetles, avoiding or running from predators isn't enough. These beetles can get a little scary. They make poison called cyanide that can be released onto the mouth of a predator. Few animals, including people, can eat cyanide without getting sick. It can even kill small predators. Many of the tiger beetles that use cyanide for protection also have bright orange body parts. Even predators that aren't the smartest can learn to recognize that bright orange patches aren't to be messed with. These predators will remember that the last time they tried to eat something bright orange, they ended up with a mouth full of bad tasting stuff. They may have even had to throw up.


Trivittata is from the Latin tri (three) + vittata (banded).

Boxelder bugs feed almost entirely on the developing seeds of boxelder, maple, and ash trees. [1] The boxelder bug is sometimes confused with insects belonging to the genus Jadera, and with the western boxelder bug (Boisea rubrolineata) which it is related to. The name "stink bug," which is more regularly applied to the family Pentatomidae, is sometimes incorrectly used to refer to Boisea trivittata. Instead, boxelder bugs belong to the family Rhopalidae, the so-called "scentless plant bugs". However, boxelder bugs are strong-smelling and will release a pungent and bad-tasting compound upon being disturbed to discourage predation. This allows them to form conspicuous aggregations without being preyed on. [4] These insects feed, lay eggs and develop on boxelder trees, most commonly occurring on female trees as they produce seeds. Boxelder bugs prefer seeds however, they also suck leaves. They can be frequently observed on maple as these trees provide them with seeds as well. Boxelder bugs overwinter in plant debris or protected human-inhabited places and other suitable structures.

Although they specialize on the seeds from maple, boxelder and ash, [1] they may pierce other parts of the plant while feeding. They are not classified as an agricultural pest and are generally not considered injurious to ornamental plantings. [5] However, they are known to damage some fruits in the fall when they leave their summer quarters in trees and seek areas to overwinter. [5] Feeding by the bugs produces dimples, scars, fruit deformation, corky tissue, and even premature fruit-drop in strawberries and some tree fruits. [5]


Identify Huge Mystery Beetle - Biology

There are over 1000 described species of anobiids. Many are wood borers, but two, the drugstore beetle, Stegobium paniceum (L.) (known in the United Kingdom as the biscuit beetle) and the cigarette beetle, Lasioderma serricorne (F.) (also known as the tobacco beetle), attack stored products. Stored product pests cause tremendous damage and economic losses to post-harvest and stored grains and seeds, packaged food products, and animal and plant-derived items and products. Besides causing direct damage by feeding, they elicit disgust, annoyance, and anger in many of those who find them infesting these products.

Figure 1. Adult drugstore beetle, Stegobium paniceum (L.). Photograph by B.J. Cabrera, University of Florida.

Distribution (Back to Top)

Drugstore beetles have a worldwide distribution, but are more abundant in warmer regions or in heated structures in more temperate climates. They are less abundant in the tropics than the cigarette beetle.

Description and Identification (Back to Top)

Adults: The beetles are cylindrical, 2.25 to 3.5 mm (1/10 to 1/7 inch) long, and are a uniform brown to reddish brown. They have longitudinal rows of fine hairs on the elytra (wing covers). Drugstore beetles are similar in appearance to the cigarette beetle however, two physical characters can be used to tell the difference between them. The antennae of the cigarette beetle are serrated (like the teeth on a saw) while the antennae of the drugstore beetle are not and end in a 3-segmented club. The other difference is that the elytra (wing covers) of the drugstore beetle have rows of pits giving them a striated (lined) appearance while those of the cigarette beetle are smooth.

Figure 2. Serrated antennae of a cigarette beetle, Lasioderma serricorne (F.), (left) and clubbed antennae of a drugstore beetle, Stegobium paniceum (L.) (right). Photograph by B.J. Cabrera, University of Florida.

Figure 3. Striated elytra of an adult drugstore beetle, Stegobium paniceum (L.). Photograph by B.J. Cabrera, University of Florida.

Figure 4. Comparison of the elytra and antennae of the cigarette beetle, Lasioderma serricorne (F.), (left) and drugstore beetle, Stegobium paniceum (L.) (right). Drawings by Division of Plant Industry.

Larvae: Small, white grubs the later instars are scarab-like. They are similar to cigarette beetle larvae, but have shorter hairs and the marking on the head ends in a straight line across the frons just above the mouthparts.

Figure 5. Larva of the drugstore beetle, Stegobium paniceum (L.). Photograph by B.J. Cabrera, University of Florida.

Figure 6. Comparison of a larva of a cigarette beetle, Lasioderma serricorne (F.), (left) and the drugstore beetle, Stegobium paniceum (L.) (Right). Photograph by B.J. Cabrera, University of Florida.

Life History (Back to Top)

Females lay up to 75 eggs in the food or substrate. The larval period ranges from four to 20 weeks. Larvae tunnel through the substrate and when fully grown build a cocoon and pupate. Pupation takes from 12 to 18 days. Adult females live approximately 13 to 65 days. The entire life cycle is generally less than two months but can be as long as seven months. The duration of the life cycle is highly dependent on the temperature and food source. Development occurs between 60 to 93°F (

15 to 34°C) but is optimal at about 85°F (

30°C) and 60 to 90% relative humidity.

Pest Status (Back to Top)

The drugstore beetle attacks such a wide variety of foods and material that one anonymous quote states that it "eats anything but cast iron." It gets its name from its habit of feeding on prescription drugs. It also feeds on flours, dry mixes, breads, cookies, chocolates and other sweets, and spices. Non-food material includes wool, hair, leather, horn, and museum specimens. It is found in pigeon nests and is known to bore into books, wooden objects, and, in some cases, tin or aluminum foil and lead sheets. Larval feeding accounts for the greatest amount of damage. Museum and herbarium specimens are vulnerable to attack. Slight damage and contamination can ruin these valuable and priceless items. Drugstore beetles harbor symbiotic yeasts that produce B vitamins. The yeasts are deposited on the eggs as they pass through the oviduct and are consumed by the larvae during egg hatch. These yeasts enable the drugstore beetle to feed and survive on many foods and other items of poor nutritional quality.

Management (Back to Top)

Home. Preventing and controlling drugstore beetle infestations is relatively simple: Insecticides should be used only as a last resort. Locating the source or sources of infestation is the first and most important step. Heavily infested items should be wrapped in heavy plastic, taken outside and thrown away. All food containers and items should be checked for infestation. Items can be placed in the refrigerator or freezer (16 days at 36°F or seven days at 25°F) to kill all stages. Place the items in a plastic bag to reduce condensation problems during thawing. Heating small quantities of infested material (190°F for one hour, 120°F for 16 to 24 hours) in an oven is also effective. Uninfested items can be cold- or heat-treated to ensure that any undetected stages are killed.

To prevent reinfestation, clean up spilled flour, mixes, crumbs, etc. and thoroughly vacuum and clean areas where the contaminated items were stored. Store foods in airtight glass, metal or plastic containers. Clear containers make it easier to check for infestation. Chemical treatment using commercially available insecticides or insect growth regulators is usually not necessary but if used, be sure to follow the label.

Commercial. The drugstore beetle is a common pest of processed and packaged food products. It is found in flour mills, bakeries, pet food, breakfast cereal manufacturing, and snack food plants, chocolate factories, confectionaries, wholesale distribution centers and sometimes retail stores. Integrated pest management (IPM) programs are often implemented to control infestations at processing, distribution, and storage facilities.

Large-scale control for severe infestations can be achieved by fumigation. However, the use of one fumigant, methyl bromide -- which destroys ozone in the atmosphere -- was banned in 2005 according to an addition to the Montreal Protocol (an international agreement signed by over 150 countries) in 1995. Heat treatment has been used with limited success. Effective control is obtained when a temperature of approximately 50°C (122°F) is maintained for 24 to 36 hours.

Residual insecticides registered for use on drugstore beetles can be applied to cracks, crevices and shelves in storage areas after removal of stored products (check labels for specific use). Insect growth regulators (IGRs) may be used as part of an IPM program. Sticky traps baited with the female sex pheromone, stegobinone, can be used to monitor for adult beetles. Mass-trapping -- which involves setting out large numbers of traps in infested areas with the intent of catching large numbers of beetles to reduce the population -- has been tried, but effectiveness is limited because only males are attracted to the traps. For mass trapping of drugstore beetles to succeed, a large enough number of males must be caught to ensure that few females will be mated. Pheromone traps are mostly used for detecting and monitoring beetle populations. The traps typically are set out in a grid-like pattern within a facility and monitored at regular intervals for trapped males. If one or more traps in a particular area happen to catch a greater proportion of beetles, then more traps are set out in that area to pinpoint the source of infestation.

Natural Enemies (Back to Top)

The drugstore beetle is attacked by a variety of generalist natural enemies. Predators include Tenebriodes sp. (Tenebrionidae), Thaneroclerus sp. (Cleridae) and several carabids. Eggs may be eaten by predatory mites. Parasitoids include wasps in the families Pteromalidae, Eurytomidae and Bethylidae. However, biological control for stored-product pests has not been widely adopted. Part of the problem is that although it reduces the amount of pesticides used for control, the release of beneficial insects to control stored-product pests increases the total amount of insects and insect parts in foodstuffs.

Chemical Ecology (Back to Top)

The drugstore beetle sex pheromone, stegobinone (2,3-dihydro-2,3,5-trimethyl-6-(1-methyl-2-oxobutyl)-4H-pyran-4-one) is used in commercially available traps and lures. Stegobinone has also been identified as the sex pheromone of a wood-feeding anobiid, the common furniture beetle, Anobium punctatum. Wind-tunnel assays in one study revealed that male furniture beetles were attracted to female drugstore beetle extracts. Thus, stegobinone-baited lures can be marketed for two different pest species. Stegobinone has also been tentatively identified as the sex pheromone of two other wood-destroying anobiids from the mid-Pacific coast of North America, Hemicoelus gibbicollis and Ptilinus basalis.

Figure 7. Chemical structure of stegobinone, a sex pheromone of the drugstore beetle, Stegobium paniceum (L.). Graphic by B.J. Cabrera, University of Florida.

Selected References (Back to Top)

  • Baur FJ. 1991. Chemical methods to control insect pests of processed foods. pp. 427-440. In Gorham JR (ed.), Ecology and Management of Food-Industry Pests. FDA Technical Bulletin 4.
  • Granovsky TA. Stored product pests. pp. 635-728. In Moreland D (ed.), Handbook of Pest Control (by Mallis A), Eighth Edition. Mallis Handbook and Technical Training Co.
  • Hill DS. 1990. Pests of stored products and their control. CRC Press, Boca Raton. 274 pp.
  • Howe RW. 1957. A laboratory study of the cigarette beetle, Lasioderma serricorne (F.)(Col., Anobiidae) with a critical review of the literature on its biology. Bulletin of Entomological Research 48: 9-56.
  • Krischik V, Burkholder W. 1995. Stored-product insects and biological control agents. pp. 85-102. In Krischik V, Cuperus G, Galiart D (eds.) Stored product management. Oklahoma Cooperative Extension Service Circular Number E-912.
  • Phillips TW. 1994. Pheromones of stored-product insects: current status and future perspectives. pp. 479-486. In Highley E, Wright EJ, Banks HJ, Champ BR (eds.), Proceedings of the 6 th International Working Conference on Stored-product Protection, Vol. 1. CAB International, Wallingford, U.K.
  • Philips TW. 1997. Semiochemicals of stored-product insects: Research and applications. Journal of Stored Product Research 33: 17-30.
  • Phillips TW, Berberet RC, Cuperus GW. 2000. Postharvest integrated pest management, pp. 2690-2701. In Francis FJ (ed.), The Wiley Encyclopedia of Food Science Technology, 2 nd Edition. John Wiley and Sons, New York.
  • Phillips TW, Cogan PM, Fadamiro HY. 2000. Pheromones, pp. 273-302. In Subramanyam B, Hagstrum DW (eds.), Alternatives to pesticides in stored-product IPM. Kluwer Academic Publishers, Boston.
  • United States Department of Agriculture. 1980. Stored-grain insects. USDA-ARS Agriculture Handbook Number 500, 57 pp.
  • White PR, Birch MC. 1987. Female sex pheromone of the common furniture beetle Anobium punctatum (Coleoptera: Anobiidae): Extraction, identification and bioassays. Journal of Chemical Ecology 13: 1695-1706.

Authors: Brian J. Cabrera, University of Florida
Photographs and Drawings: B.J. Cabrera, University of Florida Division of Plant Industry
Web Design: Don Wasik, Jane Medley
Publication Number: EENY-228
Publication Date: August 2001. Revised: July 2014. Reviewed: December 2017. Latest revision: April 2021.

An Equal Opportunity Institution
Featured Creatures Editor and Coordinator: Dr. Elena Rhodes, University of Florida


MYSTERY BITES: Insect and Non-Insect Causes

Nearly everyone experiences what seem like bug bites from time to time. The irritation might be accompanied by welts, rash, itching, or perhaps the feeling that something is crawling over the skin. Even when no bugs are apparent, the annoyance can be enough to trigger a call to an exterminator. Unfortunately, pesticides might not be the answer. Unless the underlying cause is discovered, the discomfort will likely continue.

It is important to realize that there are many causes of bite-like reactions — some of which are related to pests, and others that are not. Pest management professionals can usually provide relief if insects or mites are the culprit. If no pests are found, the customer may need to see a dermatologist or other allied professional. The following information is intended to help those who believe they have a biting pest problem where the source of irritation has not been identified.

STARTING THE INVESTIGATION

The cause of perceived ‘bug-bites’ is often far from obvious. Investigations should be thoughtful and systematic, ruling out likely possibilities through the process of elimination. A good rule of thumb in such cases is that no pesticide should be applied unless biting pests or clear evidence of them are discovered or strongly suspected. A thorough investigation is more likely to yield a solution.

Treating without a known target pest can mislead the client into thinking that spraying will fix the problem, which it seldom does. Additional (unnecessary) treatments may be requested thereafter whenever someone complains of an itch.

To conduct a careful investigation, it is useful to interview the client before inspecting the premises. In commercial settings such as an office building, this may involve talking with management as well as affected employees. A questionnaire (see the bottom of this page for the questionnaire, or view this downloadable PDF version) can be helpful for gathering facts that may solve the mystery. One of the most important questions to ask is if anyone has actually seen or captured any bugs as the irritation is occurring. With a few notable exceptions (e.g., bed bugs, certain types of mites), most pests that bite humans are likely to be seen as the irritation is felt. It’s also important to consider the pattern of bites within the building – e.g. are several people affected or just a few? Where are incidents being reported? Is there an association between the onset of symptoms and certain maintenance activities, such as the installation of new carpet, or work on the heating and cooling system? Have there been birds, bats, rodents, or other animals that could possibly be harboring parasites? Such questions can yield important clues worthy of further investigation.

THE INSPECTION

Mystery bite investigations differ from most other pest inspections because the ‘culprit’ is unknown. The list of potential irritants is long and many fall outside the realm of pest control. Inspections should initially seek to determine if biting pests are involved. If they are not, customers may still want to know about other factors that may be causing the discomfort.

During the investigation, various specimens could require identification. Those that are small will require magnification to see clearly. Ideally, specimens should be placed in non-crushable containers instead of in envelopes or under tape. Another method of capture is to install several glue traps at locations where bites have been reported. Although such traps are not always reliable, they are another potential tool that could help determine if biting pests are present.

Fig. 2: Glue traps can help to reveal pests capable of causing irritation.

Persons complaining of invisible mites or insects crawling over their skin are sometimes advised to place strips of clear cellophane tape over the affected area while the sensations are occurring. Unfortunately, this seldom reveals the cause of a mystery bite problem. Neither does collecting samples from carpet and floors with a vacuum. Industrial hygienists may use suction devices for collecting fibers and air-borne contaminants, but vacuuming by householders seldom reveals biting pests and samples are tedious to sort through and process. The appearance of bites or welts on the body can also provide clues, although ‘bug bites’ are difficult to diagnose, even by physicians.

Fig. 3: ‘Bug bites’ are difficult to diagnose, even by physicians.

The most useful tactic for these cases is knowing where and what to look for. With mystery bites, the list of potential irritants is extensive.

SOURCES OF IRRITATION

Irritations of unknown origin may be from arthropods (insects or mites) or a multitude of other factors which have nothing to do with pests. Below are the more common sources worthy of consideration.

Obscure Biting Pests

In some mystery bite cases, insects or mites truly are the culprit. These are some that should be foremost in the minds of inspectors.

Bed bugs have become increasingly common and should always be considered a possibility in mystery bite investigations. People are usually bitten at night while they are sleeping. Initially the bite is painless and victims seldom know they are being bitten. The typical reaction is itchy red welts on exposed skin appearing within a day or so of the incident – although there can be a delayed reaction over a matter of days in some cases. Others have little or no reaction to the bites. Since bed bugs also remain well-hidden, victims often are bitten repeatedly yet never see an insect. Confirmation requires finding the bugs, shed skins or dark fecal spots of digested blood, which can be difficult especially in the early stages of infestation.

Fig. 4: Bed bugs should always be considered a possibility in mystery bite investigations.

Because bed bugs are cryptic and nocturnal, visual inspection alone sometimes fails to reveal their presence. Various devices are available to help detect their presence. Among the most popular detection methods are small plastic dishes (e.g. ClimbUp®), that wandering bed bugs crawl or fall into but cannot escape due to the slippery inner surface. Typically, the devices are placed under the legs of beds and seating, or close by.

Fig. 5: Dish-shaped traps can be placed under beds and sofas to help monitor for bed bugs.

When bed bug-like insects are found, it is important to consider whether bats, birds or other wild hosts are involved. Although similar in appearance to the kind of bed bug that prefers humans, bat bugs and bird bugs require different management procedures.

Fleas are another common source of insect bites within homes. Fleas are fast moving and jump when disturbed. However, because they are brownish and about 1/8" long, they are usually noticed. Bites typically occur around the lower legs and ankles, producing a small, red, hardened, itchy welt. Fleas are most often associated with pets, although the presence of mice, rats, squirrels, skunks, possums or raccoons can also result in infestations. Animal hosts need to be present for extended periods for fleas to become established — a brief visit by a dog or cat, for example, is unlikely to cause problems. Infestations can be confirmed by examining pets, installing traps (e.g., myFleaTrap®), or walking the premises in white socks pulled high (which makes the presence of the pests more obvious).

Fig. 6: Fleas generally bite low on the leg, whereas bed bugs attack any exposed skin.

Liceare another possible source of itching and irritation. Infestations occur on the head and other hairy areas of the body. Lice are tiny, whitish-grey insects that are visible under close examination by the client or physician. Because they largely remain on the host, treatment of premises is not required nor is it recommended. The types of lice that bite humans are mainly acquired through close personal contact or sharing of hats or combs.

Fig. 7: Lice cause itching and irritation but are easy to diagnose.

Mites are tiny pests that occasionally bite and irritate people. Some feed on animals, others infest stored foods, and some dwell outdoors in vegetation. Contrary to popular belief, most mites that bite people in buildings are large enough to be seen with the naked eye. There also is no such thing as a ‘cable’, ‘computer’ or ‘paper’ mite — these terms are purely fictitious. Mite infestations in buildings can result from birds nesting in eaves, attics, etc., or from mice or rats. When a bird or rodent dies or leaves the nest, thousands of parasitic mites can migrate indoors and bite humans. Domestic fowl (chickens, parakeets, etc.), gerbils and hamsters also may harbor mites capable of biting people. Bird and rodent mites are tiny, but appear as dark slow-moving specks — they are about the size of a period. Mites cannot jump or fly.

Fig. 8: Mites infesting birds and other animals sometimes also bite people.

A few parasitic mites are too small to be seen with the naked eye. The human scabies mite burrows into the skin, causing intense itching accompanied by a rash. Skin between fingers, wrists, elbows and shoulder blades are areas most often affected. Transmission of scabies mites occurs only through close personal contact or sharing the same bed. Fortunately, scabies is a rather rare condition that is readily diagnosed by dermatologists and other competent physicians. No treatment of the premises is needed since these mites cannot survive off a human.

Various mites living indoors also infest stored food products such as grains, meats, cheese and dried fruit. Food and mold mites tend to infest items stored for long periods that have become moist or moldy. Tremendous numbers may develop in such places as pet food bags, non-refrigerated smoked meats, or caged animal litter. At times populations may disperse outward from breeding sites and annoy humans. Food and mold mites do not suck blood but can irritate the skin. They appear as tiny, pale-colored slow-moving specs on dark surfaces.

Fig. 9: Mites infesting a bag of pet food.

Other mites that can bite humans live outdoors in vegetation. Chiggers (the immature stage of the harvest mite) live in tall weeds and dense vegetation. They crawl onto people and often attach where clothing fits tightly, such as around ankles, waist or armpits. Chigger bites produce hard red welts that begin itching intensely within 24 hours. Consequently, people may not associate the irritation with being bitten outdoors the day before.

Fig. 10: Chigger bites produce hardened welts that itch intensely.

Another nearly microscopic biter, the straw itch mite, infests straw, grain or hay. Severe rash and itching results from handling infested materials in barns, stables, etc. Yet another type of itch mite inhabits the leaf galls of oak trees. In late summer or autumn, tremendous numbers of the mites can become airborne, landing on people. The bites are red, itchy, and painful, appearing on the face, neck, chest and arms. Fortunately, outbreaks of this mite are sporadic and have been reported mainly in the Midwest. Itch mites may be the culprit if the victim was outdoors near oak trees. Like chigger bites, the irritation may not be felt until the following day. Delayed reaction to bites is also common with ticks and mosquitoes, and from exposure to poison ivy/oak. Asking clients if they have spent time outdoors can help determine if such pests might be involved.

One additional mite worth mentioning is the house dust mite. Dust mites are common indoors where they feed on dander (bits of shed skin) from people and pets. Large numbers may persist in beds, couches and carpet, but are generally too small to be seen with the naked eye. People sometimes think dust mites are capable of causing itching and bite-like reactions but this is untrue. Their annoyance is limited to an ability to cause allergies, with symptoms such as stuffy or runny nose, sneezing, cough, watery eyes and asthma. Diagnostic kits for detecting house dust mites can be bought from pharmacies and allergy testing can be performed by a physician.

Thrips are tiny (1/16") straw-colored insects that feed on plants. They have piercing mouthparts for sucking plant juices but can also bite humans. The bite feels like a pinprick. In late summer, huge numbers of these insects may become airborne, landing on people’s clothing and skin. Some also may be transported on air currents into factories, warehouses, etc. Although houseplants are seldom the source for these or other biting pests, they are still worth checking during inspections.

Sand flies, also called biting gnats, punkies or no-see-ums, breed in swamps, marshes and other moist areas outdoors. They are vicious biters yet so small (1/32"- 1/8") that their presence often goes unnoticed. Fortunately, biting flies seldom breed indoors. Several other tiny flies which are harmless (e.g., fungus gnats) do occur indoors, however, and will need to be identified to alleviate client concerns.

Spiders are often thought to be responsible for bites of unknown origin. In truth, most spiders are harmless, timid creatures and bites are a rare event. When spider bites do occur, it usually is in response to being crushed or threatened they do not ‘pounce’ on a person as they would a fly. As with other potential biters, it is extremely difficult to diagnose a spider bite from the lesion alone. Lacking an actual spider doing the biting, such diagnoses even by physicians should be regarded as little more than a guess.

Non-Pest Irritants

If the investigation reveals biting insects or mites, appropriate pest control measures can be taken. If no such pests are discovered, the person should be referred to a dermatologist, industrial hygienist, or other allied professional. Following are some of the more common (non-pest) irritants that these entities may consider.

Household Products. Everyday items found in homes and buildings can cause skin reactions similar to ‘bug’ bites’. Products most often implicated include soaps, detergents and cleansers, cosmetics, hair products, medications, paper/cardboard, printing inks (as from multiform carbonless paper), and certain types of clothing, especially those containing fire retardants. Sometimes the location of the rash or irritation suggests the cause. For instance, a rash on hands and arms of factory workers might be due to cleaning compounds or materials they are handling such as cardboard. If a connection can be made to one of these possible irritants, avoiding further exposure may solve the problem. A dermatologist can confirm that a particular product, rather than a pest, is responsible.

Environmental Factors. When multiple people experience itching and irritation in the absence of pests, the cause is often some irritant in the environment. Among the most common are tiny fragments of paper, fabric, or insulation. When these adhere to skin, they can produce symptoms ranging from a mild prickling or crawling sensation to intense itching accompanied by rash, welts or sores. If fibers or fragments are involved, the irritation usually occurs on exposed areas of the body — arms, legs, face, neck, etc. Such problems are rather common where large amounts of paper or cardboard are processed, like offices, filing rooms, and distribution centers. New or badly worn carpets, drapes, and upholstery also shed fibers that can irritate skin. Laundering clothes or blankets in a washer/dryer previously used to clean curtains can likewise cause irritation due to the shedding of fiberglass and other materials. Other possibilities include sound-deadening fibers from ceiling tiles, or insulation fibers emitted from heating and cooling systems. These are especially likely if there has been recent repair work on the ceiling or air-handling system.

Fig. 11: Cardboard, fabric and insulation fibers can cause irritation mistaken for insect bites.

Irritation can be worsened by static electricity, which increases the attraction of particulates to exposed skin. Low humidity, electronic equipment, and nylon in carpeting, upholstery, or women's stockings all increase levels of static electricity and the potential for particle-induced irritation. Static electricity also causes body hair to move, giving the impression something is crawling over the skin.

If fibers or fragments are suspected, floors, furniture and work surfaces should be thoroughly cleaned. In offices, static-reducing measures can be implemented, such as raising the humidity level of the air and installing static-resistant mats under chairs. Anti-static sprays can be used to treat seating areas. Dryness alone can also cause irritation, producing a condition known as ‘winter itch.’ As skin loses moisture, itching results — a particular problem during winter and in older people. Similar reactions may occur from changes in temperature that can make skin more sensitive. A skin moisturizer can be helpful in such situations, or consult with a dermatologist.

Volatile indoor pollutants can also cause irritation. Although such compounds most often cause headaches or eye, nose, and throat discomfort, some may cause welts and rashes. Materials most often implicated include ammonia-based cleansers, formaldehyde emitted from materials such as plywood, carpet, and cardboard, tobacco smoke, and solvents and resins in paints and adhesives. Reactions often occur in industrial settings or buildings receiving new paint, wall or floor coverings. If indoor air pollutants are suspected, the client may want to contact an industrial hygienist to monitor for allergy-producing contaminants. Companies specializing in environmental health monitoring have online listings in most cities.

Medical Conditions. Health-related conditions also may cause symptoms mistaken for bug bites. Itching and irritation are common during pregnancy, especially during the last trimester. Similar symptoms are associated with diabetes, liver, kidney, and thyroid disorders, and herpes zoster (shingles). Food allergies and prescription or recreational drugs are other common causes of such symptoms. One's overall emotional state, including stress at work or home, can also trigger skin irritation. Moreover, the response can be induced in other people simply by the ‘power of suggestion.’ When one person in a group experiences itching and irritation and talks about it, others often feel the urge to scratch as well.

Fig. 12: Methamphetamine and other psychostimulant drugs can cause symptoms that mimic insect bites.

Delusions of parasitosis is a more serious emotional disorder characterized by the conviction that living organisms are infesting one’s body. Delusory parasitosis patients have similar symptoms and patterns of behavior which tend to sound unusual. Patients typically report bugs or mites invading various areas of their body — often vanishing then reappearing, or perhaps changing colors while being observed. Specimens submitted for identification (often in great quantity) usually consist of bits of dead skin, hair, lint, and other debris. The individual’s skin may have become irritated from persistent scratching, bathing, and application of ointments and chemicals. Clothing and household items often are repeatedly washed or discarded. Sufferers commonly have visited one or more doctors with no definitive diagnosis or relief.

Fig. 13a: Delusions of parasitosis patients often submit numerous samples for identification.
Fig. 13b: Self-inflicted scratches and scarring may also be evident.

While these cases may seem bizarre, they are tragically real to the patient. Sufferers often are convinced that spraying insecticides will fix the problem — but treatment of the disorder lies outside the realm of pest control. Such cases should be referred to a dermatologist or mental health professional. Unfortunately, it may be difficult to convince affected individuals to seek professional help, except perhaps by involving another family member.

SUMMARY. There is no simple way to diagnose ‘mystery bite’ complaints. Oftentimes, the itching or irritation has nothing to do with insects or mites and cannot be solved by pest control. Approaching each case in a thoughtful, methodical manner will increase the chances of finding a solution. Such sensations are real to the client, and should be addressed with care and concern.

CAUTION: Some pesticides mentioned in this publication may not be legal in your area of the country. If in doubt, please consult your local cooperative extension service or regulatory agency. Furthermore, ALWAYS READ AND FOLLOW LABEL DIRECTIONS FOR THE PRODUCT YOU ARE USING.

Please note that content and photos in this publication are copyrighted material and may not be copied or downloaded without permission of the Department of Entomology, University of Kentucky.

MYSTERY BITE QUESTIONNAIRE

    Area(s) within building where bites are occurring _______________________________

When did problem first occur? ______________ Frequency of occurrence ___________

Time of day ________________

Description of symptoms (welts, rash, itching, etc.) _____________________________

Area(s) of body affected ___________________________________

Has patient seen a doctor (e.g., dermatologist)? If so, what was the diagnosis?

Have insects or mites suspected of causing irritation been seen or captured? _______

If so, were they identified by an entomologist or other competent professional? ______

Has there been infestation of birds, bats, rodents, raccoons, squirrels, etc. within past

6 months? ________ If so, where in the building? ____________________________


Beetles Have Been Around for About 270 Million Years

The first beetle-like organisms in the fossil record date back to the Permian Period, roughly 270 million years ago. True beetles — those that resemble our modern-day beetles — first appeared about 230 million years ago. Beetles were already in existence before the breakup of the supercontinent Pangaea, and they survived the K/T extinction event thought to have doomed the dinosaurs. How have beetles survived for so long, and withstood such extreme events? As a group, beetles have proved remarkably adept at adapting to ecological changes.


Contents

The Reduviidae are members of the suborder Heteroptera of the order Hemiptera. The family members are almost all predatory, except for a few blood-sucking species, some of which are important as disease vectors. About 7000 species have been described, in more than 20 recognized subfamilies, making it one of the largest families in the Hemiptera.

The name Reduviidae is derived from the type genus, Reduvius. That name, in turn, comes from the Latin reduvia, meaning "hangnail" or "remnant". Possibly this name was inspired by the lateral flanges on the abdomen of many species.

  • Lopodytes
  • Melanolestes
  • Platymeris
  • Pselliopus
  • Psytalla
  • Rasahus
  • Reduvius
  • Rhiginia
  • Sinea
  • Zelus

While members of most subfamilies have no common names other than assassin bugs, among the many subfamilies are a few with their own common names that are reasonably widely recognized, such as:

  • Ambush bugs - subfamily Phymatinae
  • Thread-legged bugs - subfamily Emesinae, including the genus Emesaya
  • Kissing bugs (or cone-headed bugs) - subfamily Triatominae, unusual in that most species are blood-suckers and several are important disease vectors
  • the species known as the "wheel bug" - Arilus cristatus

Adult insects range from about 4.0 to 40 mm, depending on the species. They most commonly have an elongated head with a distinct narrowed 'neck', long legs, and prominent, segmented, tubular mouthparts, most commonly called the proboscis, but some authors use the term "rostrum". Most species are bright in colour with hues of brown, black, red, or orange.

The most distinctive feature of the family is that the tip of the proboscis fits into a ridged groove in the prosternum, where it can be used to produce sound by stridulation. Sound is made by rasping the proboscis against ridges in this groove stridulitrum (stridulatory organ). These sounds are often used to discourage predators. When harassed, many species can deliver a painful stab with the proboscis, injecting venom or digestive juices. The effects can be intensely painful and the injection from some species may be medically significant.

Predatory Reduviidae use the long rostrum to inject a lethal saliva that liquefies the insides of the prey, which are then sucked out. The saliva contains enzymes that digest the tissues they swallow. This process is generally referred to as extraoral digestion. [2] The saliva is commonly effective at killing prey substantially larger than the bug itself.

The legs of some Reduviidae have areas covered in tiny hairs that aid in holding onto their prey while they feed. Others, members of the subfamily Phymatinae in particular, have forelegs that resemble those of the praying mantis, and they catch and hold their prey in a similar way to mantises.

As nymphs, some species cover and camouflage themselves effectively with debris or the remains of dead prey insects. The nymphal instars of the species Acanthaspis pedestris present one good example of this behaviour where they occur in Tamil Nadu in India. Another well-known species is Reduvius personatus, known as the masked hunter because of its habit of camouflaging itself with dust. Some species tend to feed on pests such as cockroaches or bedbugs and are accordingly popular in regions where people regard their hunting as beneficial. Reduvius personatus is an example, and some people breed them as pets and for pest control. Some assassin bug subfamilies are adapted to hunting certain types of prey. For example, the Ectrichodiinae eat millipedes, and feather-legged bugs eat ants. A spectacular example of the latter is Ptilocnemus lemur, an Australian species in which the adult attacks and eats ants, but the nymph waits until the ant bites the feathery tufts on its hind legs, upon which it whips around and pierces the ant's head with its proboscis, and proceeds to feed. [3]

Some research on the nature of the venom from certain Reduviidae is under way. The saliva of Rhynocoris marginatus showed some insecticidal activity in vitro, in tests on lepidopteran pests. The effects included reduction of food consumption, assimilation, and use. Its antiaggregation factors also affected the aggregation and mobility of haemocytes. [4]

The saliva of the species Rhynocoris marginatus (Fab.) and Catamirus brevipennis (Servile) have been studied because of their activity against human pathogenic Gram-negative bacteria (including strains of Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Salmonella typhimurium) and the Gram-positive (Streptococcus pyogenes).

Some species are bloodsuckers rather than predators, and they are accordingly far less welcome to humans. Triatoma species and other members of the subfamily Triatominae, such as Rhodnius species, Panstrongylus megistus, and Paratriatoma hirsuta, are known as kissing bugs, because they tend to bite sleeping humans in the soft tissue around the lips and eyes. A more serious problem than their bites is the fact that several of these haematophagous Central and South American species transmit the potentially fatal trypanosomal Chagas disease, sometimes called American trypanosomiasis. This results in the death of 12,000 people a year. [5]

Current taxonomy is based on morphological characteristics. The first cladistic analysis based on molecular data (mitochondrial and nuclear ribosomal DNA) was published in 2009 and called into question the monophyly of some current groups, such as the Emesinae. [6] The oldest fossils of the family are from the Late Cretaceous (Cenomanian) aged Burmese amber, represented by nymphs [7] and the genus Paleotriatoma, belonging to the subfamily Triatominae. [8]


Watch the video: BITTEN by a GIANT WATER BUG! (May 2022).