Little Bugs with a Big Bite: Minute Pirate Bugs

Sometimes it seems the tiniest of insects is the biggest nuisance. Mosquitoes come to mind, as well as black flies, and "no-see-ums" or "punkies" (biting midges in the family Ceratopogonidae). One other insect often responsible for surprisingly painful bites is the aptly-named "minute pirate bug." There are about 90 species in the family Anthocoridae found in North America, in 22 genera, but only a few cause us grief.

Insidious Flower Bug biting me in Colorado

The Insidious Flower Bug, Orius insidiosus is, appropriately, the species most likely to get under your skin. Well, on your arm, hand, or neck, where it will likely probe you painfully. At only 2-2.5 millimeters, it is possible to overlook it entirely when trying to pinpoint the source of your irritation. In the right light, however, the little bug appears bright white and black.

Despite dispensing unprovoked bites, Orius insidiosus is actually a highly beneficial bug. It is a predator of many crop pests like very young caterpillars of the corn earworm, plus insect eggs, aphids, whiteflies, thrips, and mites. Consequently, this minute pirate bug is reared commercially and sold to farmers as a biocontrol agent.

It takes only twenty days, on average, for O. insidiosus to go from egg to adult. Females lay two eggs per day, and about thirty during their lifetime. Each ovum is deposited in foliage such that the top of the capsule protrudes above the leaf surface. In about four or five days, the first instar nymph emerges from the egg. During the next two or three weeks, the nymph goes through a total of four more instars before transforming into a fully-winged adult bug. The adults live an additional three or four weeks.

Insidious Flower Bug biting me in Kansas

Adult Insidious Flower Bugs overwinter in leaf litter and probably other debris on the ground. Several generations can be produced annually over the insect's wide geographic range. It occurs east of the Rocky Mountains, plus parts of California, and has been introduced to British Columbia. Because it is available commercially, it has likely spread elsewhere, too.

Adult Anthocoris musculus, Colorado

Another species I have found commonly here in Colorado Springs is Anthocoris musculus. It is a real giant by pirate bug standards, measuring 3.4-4.0 millimeters as an adult. I have found it associated with cottonwood trees, and it is well-known from willows and other deciduous trees and shrubs as well as herbaceous plants.

Nymph of Anthocoris musculus, Colorado

It is potentially an important predator in orchards, and has been observed eating red mites and "eye spotted bud moth" in Nova Scotia (Kelton, 1978). This species ranges throughout most of North America including Alaska and northern Canada.

The next time the pirate bug bites, simply utter "Ar-r-r-r!" and remember their beneficial qualities. After all, they are probably keeping your garden free of other tiny pests.

Adult A. musculus feeding on unknown object, Colorado

Sources: "Minute Pirate Bug aka. Orious insidiosus," Evergreen Growers Supply.
Gibb, Tim. 2006. "Have a thick skin when it comes to Insidious Flower Bugs," Purdue Plant & Pest Diagnostic Laboratory, Purdue University Extension
Hull, L.A. and R.L. Horsburgh. "Minute Pirate Bug, Orius insidiosus (Say)," Mid-Atlantic Orchard Monitoring Guide.
Kelton, Leonard K. 1978. The Anthocoridae of Canada and Alaska. Ottawa: Canada Department of Agriculture. Publication 1639. 106 pp. (PDF).
Slater, J.A. and R.M. Baranowski. 1978. How to Know the True Bugs. Dubuque, Iowa: Wm. C. Brown Company Publishers. 256 pp.

ArachNovember?

Last month we celebrated "Arachtober" over on the Flickr photo-sharing website, but with the unseasonably warm weather we have had here at home along the Front Range in Colorado, we're still seeing plenty of spiders this first week of November. Ok, we also cheated a little and took a trip into the heart of New Mexico, but it all goes to reveal how surprisingly long-lived some arachnids can be, and their different strategies for surviving the winter.

Male platform spider, Microlinyphia sp.

Fall is the time when the males of many a spider species go wandering in search of mates. So, it was not surprising to find a male "platform spider," genus Microlinyphia, in a restroom on the Bosque del Apache National Wildlife Refuge in New Mexico last Monday. I found out that the genus is easily recognized by the circular filament seen in the image above that issues from the male's pedipalp. This hair-like structure is called the "embolus," and it is the channel through which sperm travels during mating.

another view of the Microlinyphia platform spider

Female and immature male platform spiders live on flat, sheet-like webs built close to the ground amid grasses and low plants. The spider clings upside down to the underside of the web. Morning dew can make the webs much more obvious than they normally are.

Once mated, a female spider usually produces one or more egg sacs, as this labyrinth spider, Metepeira sp., has done. She has two egg sacs behind her in the image below, inside the tubular retreat she is at the mouth of. We found her near the platform spider, but outside along a railing around the "Flight Deck" at the refuge. Labyrinth spiders build a combination orb web and tangled snare.

Labyrinth spider with egg sacs behind her

The egg stage is a great way for an embryo or spiderling to spend the cold months, insulated within layers of silk spun by their mother. The eggs often hatch within the package, the spiderlings biding their time until the weather becomes favorable for their emergence.

Ghost spider female

At the bed-and-breakfast inn where we stayed in New Mexico, I found what must be a very pregnant female ghost spider, family Anyphaenidae, prowling the exterior of the house at night. Back home in Colorado Springs, before we left on vacation, I spotted a similarly bloated female jumping spider, Phidippus asotus on the downspout right outside our townhouse.

Female Phidippus asotus jumping spider

Inside the bed-and-breakfast, a pair of male cellar spiders in the genus Physocyclus were hanging around the web of a female in a corner of the ceiling. Below is one of the males approaching the female. Physocyclus seems to replace the Long-bodied Cellar Spider (Pholcus phalangioides) as the usual "indoor" cellar spider in the southwest U.S.

Male (left) and female cellar spiders, Physocyclus sp.

It is not only spiders that are out and about, but also harvestmen, appropriately-named arachnids for their season of abundance. You may know them as "daddy long-legs," but that name is widely applied to cellar spiders, even crane flies (in England at least). The one shown below is likely Phalangium opilio, a much-studied species native to Europe but now found all over the globe. They can survive the winter as eggs, adults, or immature specimens.

Harvestman: not a spider but still an arachnid

Fall is apparently also a time when young spiders disperse through "ballooning." I will eventually devote an entire post to this phenomenon, but it involves the spiders climbing up vertical objects. Consequently, you can reliably find spiders atop fence posts, mailboxes, utility boxes (for cables, electrical, phone), as they try and catch the wind and literally fly off to greener pastures. Crab spiders and wolf spiders in particular seem to be doing this right now. The little wolf spider below parachuted onto our car at Bosque del Apache in New Mexico.

Little wolf spider on our car roof

Just the other day (Friday), I found a young running crab spider, Thanatus sp., on a utility box here in Colorado Springs.....

Running crab spider, Thanatus sp.

followed by a ground crab spider, Xysticus sp., on top of a "stucco" mailbox post. Both seemed intent on ballooning, especially the Xysticus, which stood on tiptoe (tip-tarsus?) every time a slight breeze came up.

Xysticus crab spider

Finally, inside our very townhouse, Heidi discovered a female funnelweb weaver, Hololena sp., in her web atop our fireplace mantle.

Funnelweb weaver, Hololena sp.

We welcome our arachnid friends, even indoors, to help dispatch pesky flies and other insects that we don't appreciate nearly as much. We hope that your own holiday spirit of friendliness likewise extends to spiders, harvestmen, and related critters, even if it means you gently "relocate" them back outdoors.

Large-headed Grasshopper

I am fortunate to be surrounded by a community of entomologists with a collectively vast knowledge of insects and arachnids, and I meet more of these scholars seemingly every week, at least in the digital world of listservs and social media. I owe it to one such expert, Dr. Charles Bomar, for the identification of the fortieth (40th) species of grasshopper that I have now seen in Colorado Springs alone: the Large-headed Grasshopper, Phoetaliotes nebrascensis.

I encountered the critter on the Rock Island Trail, a concrete bike path through residential and commercial areas in eastern Colorado Springs, on October 26 as my wife and I were walking our dog. I snapped only two images, figuring this was something already familiar, in the genus Melanoplus.

Consulting book and online resources at home I was surprised I couldn't find an immediate match. So, I posted the image shown above to the Orthopterist's Society group page on Facebook. Almost immediately I received an answer from Dr. Bomar. He went on to suggest even more important references that I should have, including a link to one of them.

This is the kind of "above and beyond the call of duty" that is typical of most professional entomologists who consider it an obligation to interact with amateurs and the general public. I, for one, am eternally grateful, and could not produce this blog without their help.

Back to the grasshopper. Phoetaliotes nebrascensis is found in places other than Nebraska, ranging widely from southern Alberta, Saskatchewan, and Manitoba to extreme northern Mexico; and from eastern Washington and Oregon, the northeast corner of California, east to the northern half of Texas, Missouri, and Illinois to southwest Michigan, southern Wisconsin and Minnesota.

Adult specimens are most often found from late July through October, at least here in Colorado.

The mature insect measures 21-25 millimeters (males) or 23-33 millimeters (females), and typically has only very short front wings, missing the hind pair of wings entirely. They are therefore frequently confused with subadult specimens of other species. Occasionally there are fully-winged males of the Large-headed Grasshopper, but it is unusual to find them.

The color pattern of this species is so similar to other species that one cannot readily distinguish them based on those variable characters. Once again it is the shape of the male genitalia at the tip of the abdomen that is useful in identification. An overhead or rear view of the entire insect will, however, reveal the swollen head that gives this species its name. The head is noticeably wider than the thorax.

The Large-headed Grasshopper can be common in a variety of habitats, even being a dominant species, especially in tallgrass prairies. Both grasses and broadleaf herbs are on its menu, but it seems to prefer rangeland grasses. It is considered a low-grade pest at worst, but is usually inconsequential. It prospers with spring rains, populations rising dramatically under such conditions.

I can hardly wait to see what "new" grasshoppers turn up next year here in the Springs. There are some that I know occur here that I just haven't seen yet, so my bugwatching list is sure to grow.

Sources: Capinera, John L., Ralph D. Scott, and Thomas J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca, NY: Comstock Publishing Associates (Cornell University Press). 249 pp.
Capinera, J.L. and T.S. Sechrist. 1999. Grasshoppers (Acrididae) of Colorado: Identification, Biology, and Management. Fort Collins: Colorado State University Experiment Station Bulletin 584S.
Johnson, Dan L. 2008. Grasshopper Identification and Control Methods to Protect Crops and the Environment. Ottawa: Agriculture and Agri-Food Canada.

Black Carpet Beetles, Attagenus spp.

Among the more common household pests you are likely to encounter are the Black Carpet Beetles in the genus Attagenus, family Dermestidae. They are slightly larger, more oval, and jet black compared to the usually more abundant Anthrenus carpet beetles, but they share similar feeding habits.

Adult Black Carpet Beetle

There are nine species of Attagenus known from north of Mexico. Most are about 3-5 millimeters in length as adults. The larvae are distinctive in being tapered from front to back, with a bundle of long hairs extending from the rear end. At maturity the larva is about 9.5-12.7 millimeters, excluding the "tail" of hairs.

Larva of Black Carpet Beetle

As is the case with other carpet beetle larvae, the hairs can cause dermatitis in some people. The patient may frequently interpret the symptoms as insect "bites," resulting in misdiagnosis by physicians. It usually takes years of exposure to carpet beetle infestations to begin exhibiting reactions, but in rare instances, inflammation of the respiratory tract and eyes can also occur.

While the larvae feed mostly on dried animal products such as shed hair and skin cells from people and pets, wool garments and blankets, silks, furs, animal hides, and dead insects that collect in spider webs, light fixtures, and along window sills, they also consume dried plant matter on occasion, especially cereals and grains. So, they can be a pantry pest as well as a clothes closet pest.

Adult Attagenus feed on flower pollen

Control and prevention of a Black Carpet Beetle infestation is best achieved by thorough cleaning of one's domicile, through vacuuming up accumulated pet hair, and dust (most of which is flakes of dead skin from people and pets). Discard any infested items. Outdoors, remove abandoned mammal, bird, and wasp nests. Understand that despite all your efforts, it is next to impossible to become immune to the occasional infestation.

Insects are incredibly adept at exploiting human behavior and household ecosystems. Few are as efficient as Black Carpet Beetles when it comes to scavenging our food and clothing. They are to be despised, no doubt, but also admired for their adaptability.

Sources: Evans, Arthur V. 2014. Beetles of Eastern North America. Princeton, NJ: Princeton University Press. 560 pp.
Gahlhoff, Jerry G., Jr. 2013. "Black Carpet Beetle," Featured Creatures. Entomology and Nematology, University of Florida/Institute of Food and Agricultural Sciences. Publication Number EENY-18. Note the image of the adult beetle depicts a Dermestes species, not Attagenus.
Jacobs, Steve. 2010. "Carpet Beetle Dermatitis," Insect Advice from Extension. College of Agricultural Sciences, Pennsylvania State University.
White, Richard E. 1983. A Field Guide to the Beetles of North America (Peterson Field Guides). Boston: Houghton Mifflin Company. 368 pp.