Tuesday, October 29, 2013

Red-shouldered Bug

Today’s edition of “True Bug Tuesday” is all about the Red-shouldered Bug, Jadera haematoloma, family Rhopalidae. Last week, my wife and I happened upon a large number of this species in various life stages here in Colorado Springs. I went back a couple of times to get more and better images.

At first glance, it is easy to mistake Red-shouldered Bugs with boxelder bugs in the genus Boisea. Indeed, they both fall under the more general category of “soapberry bugs,” named for the affinity of these insects for the fruits of certain trees in the family Sapindaceae. Their appetite extends far beyond the berries and seeds of those and other trees and plants, though. They have been observed feeding on flower buds, oozing sap, and even dead insects.

Adults of Jadera haematoloma are overall slate gray with fewer red markings than boxelder bugs. They measure 9.5-13.5 millimeters in body length. Some specimens are brachypterous, meaning they have shorter wings than normal, revealing a bright red abdomen with a black bar or two on those exposed segments.

Nymphs lack wings, so the front half is gray while the back half is red. The nymphs can get very bloated while feeding, as demonstrated by the one imaged below. The nymphs pass through five instars (an instar is the interval between molts) before reaching adulthood. Freshly-molted adults are bright pink or orange.

There are usually at least two generations per year, more in the southernmost states. The bugs mate “tail-to-tail” and are thus easily distinguished from solitary individuals. Females unreceptive to mating signal that fact to approaching males by making noise. They stridulate by rapidly rubbing lateral edges of the abdomen against the adjoining thoracic segments.

A mated female digs a hole about one centimeter in depth in dry soil. There, guarded by the male, she lays a batch of up to twenty eggs. The ova hatch in about two weeks. One female, which usually mates multiple times with different males, can produce between 400 and 800 eggs in her adult lifetime.

Both nymphs and adults can overwinter in cracks, crevices, and other cozy niches. They occasionally take shelter inside homes and other buildings like boxelder bugs, rendering them a “nuisance pest” in some places.

The Red-shouldered bug is also known as the Goldenrain Tree Bug. It is native to the U.S. from Virginia south to Florida and west to Wisconsin, Kansas, Colorado, Arizona, and southern California. South of the border the species occurs from Mexico and the Caribbean to Colombia and Venezuela. It has also been accidentally exported overseas, at least to Asia.

This insect is easily confused with boxelder bugs, and any number of seed bugs in the family Lygaeidae which can be of similar size, coloration, and abundance. One must look at various subtle structural characters, rather than color and pattern, to distinguish them with any degree of certainty. With practice, however, one can render a confident ID in the field.

Sources: Carroll, Scott P. 2013. “Jadera haematoloma,” Soapberry Bugs of the World.”
Eaton, Eric R. and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Boston: Houghton Mifflin Company. 392 pp.
Jing-Fu Tsai, et al. 2013. “The soapberry bug, Jadera haematoloma (Insecta, Hemiptera, Rhopalidae): First Asian record, with a review of bionomics,” Zookeys 297: 1-41.
Slater, J.A. and R.M. Baranowski. 1978. How to Know the True Bugs. Dubuque, Iowa: Wm. C. Brown Company Publishers. 256 pp.

Monday, October 21, 2013

Brown Recluse

The Brown Recluse, Loxosceles reclusa, is without question the most infamous spider in the United States. Frequently maligned as the cause of serious necrotic wounds, and often confused with many harmless species, its reputation is inflated far beyond reality.


Also known as the “fiddleback” and “violin spider,” Loxosceles reclusa is usually marked distinctively on the carapace. This dark, violin-shaped marking may be vague, or even absent; and many other spiders have similar contrasting patterns. The only way to positively distinguish Loxosceles species is by their eyes. Brown spiders have only six eyes, compared to the usual eight eyes most spiders have. This sextet of ocular organs is arranged in a triangular pattern of three pairs. Understandably, most people don’t want to get close enough to a spider to see its eyes, but that is what is necessary to confirm an identification. Many other spiders are similarly colored, and of similar size. Recluse spiders attain a body length of 5-13 millimeters, with a legspan up to 30-40 millimeters.

Geographic Range

The Brown Recluse is native only to the central and southeast U.S., from Texas to northern Georgia, southeast Nebraska, southwest Ohio, and states in between. There are twelve other species of Loxosceles in North America, two of which are accidental introductions from other parts of the world. The Chilean Recluse, L. laeta, is found in only a few old, historical buildings in greater Los Angeles. The Mediterranean Recluse, L. rufescens, has turned up in many large urban areas, but is again usually restricted to a few highly localized populations. The remaining ten Loxosceles species are confined to the southwest U.S., from south Texas to southeast California and southern Nevada, and are found outdoors more often than in dwellings and other structures. While it is possible for any of the brown spiders to be transported outside their normal geographic range via commerce or travel, the Brown Recluse is less likely to spread than the foreign species.


The medical significance of the Brown Recluse has been sensationalized by the media and the internet. Various websites display graphic images of the most extreme cases of envenomation, if the pictures even represent spider bites at all. Yes, the venom of Loxosceles is cytotoxic (destroys tissues), and can produce necrotic wounds in some bite victims. However, many other maladies can express similar symptoms. MRSA (Methicillin-resistant Staphylococcus aureus) is one of these. More to the point, spider bites in general are a rare phenomenon. They are simply overdiagnosed. You owe it to yourself to read this article by Dr. Richard Vetter, and insist that your physician rule out those other potential causes if you ever present what you believe is a “spider bite.”

Should you ever present with a suspected or confirmed spider bite, run, don’t walk, away from any physician who applies electric shock to “deactivate the enzymes in the venom.” This is not a practice endorsed by any respected body of doctors, yet I personally know one bite victim in a rural area who received such “treatment” back in the year 2000.


It is relatively easy to avoid the prospect of a spider bite by taking simple precautions, such as those outlined in this article from Spiders.us. Simply never put your hands in places you can’t see. Do be careful moving items that have been stored for lengthy periods without disturbance, especially clothes and linens, as spiders frequently hide in garments and blankets. One of the specimens depicted here was in the folds of a blanket that was taken out of storage in a home in Leavenworth, Kansas.

Natural History

The Brown Recluse earns its name for its shy nature. They hide in narrow cracks and crevices, under stones or other objects, from which they spin a thin, haphazard, vaguely sheet-like web. Sometimes they wander out of their snares, especially at night. They are surprisingly tolerant of others of their kind, so large populations may occupy a small area. The family living in one home in Kansas City, Kansas collected 2,055 specimens in only six months. No one in the household was ever bitten, either. Individual recluse spiders in captivity live 2-3 years.


You should really not fear the Brown Recluse, but do give it respect. Exercise caution in places that you do not visit frequently, like the storage shed, cellar, deep recesses of the garage, and similar structures. Do not assume that every spider you see is a recluse. Male spiders of nearly all species, including those normally confined to webs, will wander in search of mates and may stray indoors in their quest for love. Should you really be concerned, take the specimen to an entomologist or arachnologist at a university, natural history museum, or even the public health department to have it properly identified.

Sources: Bradley, Richard A. 2013. Common Spiders of North America. Berkeley: University of California Press. 271 pp.
Forks, Thomas P. 2000. “Brown Recluse Spider Bites,” J. Am. Board Fam. Med. 13(6): 415-423.
Kaston, B.J. 1978. How to Know the Spiders (3rd edition). Dubuque, Iowa: Wm. C. Brown Company Publishers. 272 pp.
Vetter, Rick. 2004. “Causes of Necrotic Wounds other than Brown Recluse Spider Bites,” UCR Spiders Site. University of California-Riverside
Ubick, D., P. Paquin, P.E. Cushing, and V. Roth (eds.). 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.

Friday, October 18, 2013

No Answers

It dawns on me that I did not follow up on a previous post where I hinted that ”something really big” might be headed my way. Alas, it was not to be, and the decision has taken some of the air out of my hopes for the future.

Last spring, Answers.com approached me to ask if I would please apply to be their Insect Category Leader for their attempt to go head-to-head with About.com as a major source of online content. I complied by taking the editing test, submitting a sample blog post, and attaching my resumé. Then I waited. And waited.

I tried not to invest too many emotions and expectations in this opportunity, but it would have paid very well for an online enterprise, would have raised my public profile even higher, and most importantly let me reach a much broader audience with facts in the face of the proliferation of myths and urban legend that surround so many insects and arachnids. I truly see it as my mission to improve public understanding and appreciation of all misunderstood and feared animals, be they arthropods or vertebrates.

I periodically touched base with my contact person at Answers.com, and she was very gracious, honest, and punctual in her replies. I finally made one last contact on September 30 and received a reply the next day. The executives chose someone else to be the Insect Category Leader. I was devastated. I feel an obligation to provide at least a small amount of regular income to my marriage (one year and six months as of October 29), and I really thought this was my ticket.

I pressed for an explanation and was told that the only reason I was not selected is because I had done “work” for AllExperts.com, a subsidiary of About.com, which they see as their major competitor. Well, that “work” was all volunteer, to help build my credibility. Indeed, I was ranked as one of the top 50 experts, in all categories (remember doctors, lawyers, and others are on there, too), for 2009. The idea that a potential employer would use that against me, and assume that I would not resign from that “position” if I was hired left me outraged.

This is not the first time something like this has happened. I applied to be the paid expert for the “Pest Control” category at About.com years earlier, and their process is much more rigorous. I was new to writing for the internet, too. In the end, I was not selected for that position, either, due to philosophical differences as near as I could tell. After all, I make no secret of the fact that one of my major goals is to save people time and money by letting them know they rarely need professional extermination services, or over-the-counter chemical controls.

The only conclusion I am left with is that I am supposed to go out on my own. I am honored and grateful that the web wizard who brought you Spiders.us is willing to help me do just that. I have purchased the domain names “Eaton Insect Guides” and “Insect Field Guide,” and we are working methodically to get at least one of those sites erected. The remaining URL will likely funnel directly to the one we end up using.

The commercial site will be geared to addressing non-spider arthropods that I know people ask about consistently. I will need to solicit images of some of them. Eventually, there will be a forum component whereby users will be able to ask me, and the expanded community of people that results from having a forum, about insects and arachnids and other “bugs” they want to know more about.

Meanwhile, I will continue to post to this blog, at least sporadically, because my audience here seems more interested in learning about relatively obscure species that usually must be searched for. I appreciate your patience (and donations if you see fit) while I attempt to juggle both projects, plus Sense of Misplaced where I write about social and cultural issues and human nature. Thank you.

Sunday, October 13, 2013

Woodlouse Hunter

This installment of “Spider Sunday” features yet another arachnid that causes undo consternation and fear among homeowners who encounter it inside their residences. The Woodlouse Hunter, Dysdera crocata, North America’s only representative of the family Dysderidae, is not dangerously venomous to the average, healthy human being or family pet.

That is not to say that this species doesn’t look formidable. It ranges from 9-15 millimeters in body length, and has very large chelicerae (jaws) with long fangs. The cephalothorax and legs are bright reddish brown or orange, and the abdomen beige or gray in color. These spiders have only six eyes instead of the usual eight that most spiders have, and they are arranged in a compact semi-circle at the front of the cephalothorax.

The Woodlouse Hunter is actually native to the western Europe, but has been introduced over much of the globe through commerce and other forms of human travel and enterprise. Here in North America it is most common in urban areas, favoring disturbed habitats in both forest and field.

Dysdera crocata is nocturnal, hiding by day under stones, logs, and boards or other debris. It ventures out at night in search of prey. The preferred prey is apparently terrestrial isopods known as woodlice, also called “sowbugs.” Sowbugs are also native to Europe, but now abundant in the U.S. and Canada. The spider uses its enlarged jaws and long fangs to pierce their armored prey, or turn it over and stab it in its soft underbelly. Captive Woodlouse Hunters will readily take other small animals as prey, so they are more plastic in their feeding habits than their name suggests.


The life cycle, revealed by captive rearing, is lengthy. It takes about eighteen months for an individual spider to reach maturity after hatching from the egg. A given specimen can then live an additional two to three years. Mating probably take place in the spring. Females contain a batch of up to seventy (70) ova within a rudimentary egg sac consisting of only a few strands of silk.

Look for the Woodlouse Hunter under objects outdoors. They may be hiding inside an oval, silken retreat, which they spin for purposes of molting and overwintering. Sometimes, the spiders stray indoors, and that is where they are most conspicuous. While there have been documented bites by this species, the symptoms amount to only localized pain lasting an hour or so, due mostly to the mechanical injury caused by those long fangs.

Dysdera is easily confused with Broad-faced Sac Spiders I the genus Trachelas, which have a nearly identical color pattern. Note that Trachelas has eight eyes, arranged in two rows across the wide front of the cephalothorax. Trachelas also lacks the long jaws and fangs of the Woodlouse Hunter.


I am keeping the specimen of Dysdera imaged here as a potential display animal I can take to public educational events. The more that can be done to alleviate our collective fear and loathing of spiders the better, and the Woodlouse Hunter can be a great ambassador for that mission.

Sources: Bradley, Richard A. 2013. Common Spiders of North America. Berkeley: University of California Press. 271 pp.
Jacobs, Steve. 2013. “Spider: the Woodlouse Hunter,” Fact Sheet. Penn State University Entomology Department.
Ubick, D., P. Paquin, P.E. Cushing, and V. Roth (eds). 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.

Friday, October 11, 2013

"Is it poisonous?"

Hardly a day goes by when I am not asked some version of this question. Maybe it is phrased “Is it dangerous?” or “Is it venomous?” This illustrates just how paranoid we have become of other life forms on this planet. Let’s clarify the definition of each of these terms, and the relative risks involved with each.

Most of the time, people use the terms “poisonous” and “venomous” interchangeably. What they usually want to know whether a given spider, scorpion, or insect is venomous. Venomous animals possess toxins that they deliver to a victim by biting or stinging. Nearly all spiders are venomous, as that is how they kill their prey. Only a handful of spiders are dangerously venomous to the average, healthy human being. Here in North America, the only spiders confirmed to be potentially dangerous are widows (genus Latrodectus), and brown spiders (genus Loxosceles). This is not to say that the bite from *any* spider cannot spark an allergic reaction in someone hypersensitive to venoms.

Western Black Widow (female)

What is generally exaggerated is the risk of being bitten by a spider. The likelihood of being envenomated by a spider is quite miniscule, especially if you take simple precautions like those suggested in this article at Spiders.us.

Some venomous insects can come as a surprise to the uninformed or uninitiated. Several caterpillar species, for example, have stinging spines or hairs that can cause excruciating pain, at least in some people. Be careful not to touch hairy or spiny caterpillars.

Flannel Moth caterpillar

Ironically, tarantulas in the genus Aphonopelma will kick tiny, barbed hairs off of their abdomen instead of biting in self-defense. The hairs become airborne and, if inhaled or otherwise contact mucous membranes, cause severe irritation or even allergic reactions. Some people who handle tarantulas, or even the molted exoskeleton, may pay for the experience with contact dermatitis.

Wheel Bug adult

Many species of ants other than fire ants are capable of stinging, as can “velvet ants,” wasps in which the female gender is wingless and may resemble a large, hairy, brightly-colored ant. Assassin bugs like the Wheel Bug, and aquatic bugs like giant water bugs (aka “toe-biters”), backswimmers, and water scorpions, have a venomous bite to immobilize prey, but they can bite in self-defense, too. I can speak from experience that it is not pleasant.

Giant Centipede

Centipedes, fast-moving, snake-like arthropods with “too many legs,” are venomous, their first pair of legs modified into fangs they use to subdue their prey or defend themselves. Scorpions, arachnids related to spiders have a venomous stinger at the end of their telson (“tail”), but only the “bark scorpion,” Centruroides sculpturatus, is dangerously venomous. It occurs only in Arizona, western New Mexico, southern Nevada and Utah, and extreme southeast California.

The term poisonous means that an organism is toxic if ingested (swallowed). A startling number of insect species actually are poisonous and it pays to learn which ones, especially if you have curious toddlers prone to putting things in their mouths. Fireflies are very poisonous, as their bodies contain lucibufagins, toxins closely related to the toxins in toads.

Blister Beetle, one of many species

Blister beetles (image above) are aptly-named, for when molested they ooze a liquid substance containing cantharidin, an irritant that can raise blisters on sensitive skin. Even worse, if eaten, they can be lethal. Ranchers must be careful that blister beetles are not accidentally baled in hay. Horses that swallow beetles along with hay can die.

Millipedes, slow-moving, worm-like arthropods with lots of legs, are vegetarians, but most can defend themselves with harsh chemical secretions. Some species, like the one shown below, ooze cyanide compounds to repel potential predators. Others produce substances that can stain, or even burn, the skin.

Flat-backed Millipede

Luckily, many venomous and poisonous insects and spiders are aposematic. That is, they are marked with bright, contrasting “warning colors” such as black and yellow, orange, or white. There are many completely harmless insects that mimic those dangerous species, but when in doubt it pays to avoid handling brightly-colored animals.

While I do want people to find fascination in insects, spiders, and other invertebrates, I also want the public to stay safe and healthy. Be careful out there.

Monday, October 7, 2013

The Emerald Ash Borer Invades Colorado

I am usually excited in the positive sense when insects make headlines, but there are exceptions. It was devastating to learn recently that the Emerald Ash Borer, Agrilus planipennis, has been detected here in Colorado. Why is this discovery such a big deal? It has to do in part with the customary response to this exotic invader in other locations where it has shown up.

The Colorado Department of Agriculture announced on Friday, September 27, 2013 that the Emerald Ash Borer (EAB) had been discovered in Boulder County earlier in the month. While ash trees are apparently not native to Colorado, they are planted widely as part of the “urban forest” in many cities along the Front Range. Consequently, those trees are vulnerable to this invasive pest.

The reaction of many municipalities to the presence of EAB is the pre-emptive removal of the insect’s host trees. Visions of a wholesale slaughter are going through my mind right now. It is not pretty. It is costly, too, and leaves one less alternative for greenery and shade in what is a pretty bleak landscape on the fringe of the Great Plains. Shade is hard to come by, and there are few tree species that don’t have objectionable side effects. Cottonwoods shed copious amounts of cottony seeds in the spring. Locust trees grow quickly but their falling leaves get sucked into car air filters and find their way into every crack and crevice.

The thing that is really tragic is that the spread of the EAB is pretty much preventable. Various agencies and organizations have tried to get out the message about not moving firewood between states (even between counties), but the plea has either fallen on deaf ears, or not been broadcast loud enough. This is such an important message that it really warrants the Ad Council’s help in airing public service announcements on television and radio.

What is the history of this pest, you ask. According to EmeraldAshBorer.info, the Emerald Ash Borer was first discovered in the United States near Detroit, Michigan in 2002. At least, that is when entomologists first recognized it. It could have been present prior to 2002. Authorities surmise that it probably arrived in solid wood packing material originating from its native Asia. In short order the EAB was also found in Ontario, Canada, Ohio, and northern Indiana (by 2004). More were detected in northern Illinois and Maryland in 2006, then western Pennsylvania and West Virginia in 2007, followed by Missouri and Virginia in 2008. Since then it has also turned up in Minnesota, New York, Kentucky, Iowa, Tennessee, Connecticut, Kansas, Massachusetts, New Hampshire, North Carolina, Georgia, and now Colorado.

The life cycle of the beetle makes it difficult to quickly detect and almost impossible to control. The adult beetles typically emerge in mid-late May, with peak numbers in late June. Mated females begin laying eggs within two weeks of their emergence. The larvae hatch in about one to two weeks and begin boring into the inner bark and cambium layer of the host tree, disrupting the transportation of nutrients to the top of the tree. The larvae continue boring from late July to early October, overwintering in a chamber where they will pupate in the early spring. Sometimes the cycle is extended to two years.

The only symptoms of an EAB infestation outwardly visible are the gradual and subtle thinning of the tree’s canopy, and dying of branches in the uppermost reaches. Small trees can be killed by the beetle in one or two years, whereas larger trees may succumb in 3-4 years. The beetle probably selects stressed or otherwise already weakened trees as preferred hosts, but healthy trees can be attacked, too. The ongoing drought in the Front Range enhances the probability of the EAB becoming a widespread problem very quickly.

Please be on the lookout for the Emerald Ash Borer in your own state, province, or county, whether or not the species has already been detected there. Report your observations to your state department of agriculture, taking them specimens whenever possible. Thank you.

Saturday, October 5, 2013

When "Arachtober" Attacks!

October is one of my favorite months, made all the sweeter in the last three years because I have participated in the “Arachtober” group on Flickr.

Many folks who photograph insects and other small animals save the spider images they have accrued over the year to share with the Arachtober pool. This is because one of the few rules of the group is that you post only those images that have not appeared on your Flickr photostream previously. It is worth the wait.

Sometimes, participants forget that there are other arachnids besides spiders: mites, ticks, scorpions, whipscorpions, pseudoscorpions, harvestmen, and others. A few members of the group actually find things like ticks to be too disgusting to embrace even in the artistic sense. A few scorpions and “daddy long-legs” pictures will still manage to appear, though.

The biggest challenge to Arachtober’s popularity this year may be the graphic changes brought to Flickr as a whole by its new owner, Yahoo!. Fewer people view my own photostream any more because of the new format that has rendered Flickr just a shadow of its former clean, aesthetic past. The initial outrage demonstrated by the Flickr faithful has either faded, been completely ignored by Yahoo!, or both. The future of photosharing may be Facebook, Pinterest, Twitter, and Instagram, but mobile devices really don’t do quality images justice.

All the same, I invite you not only to follow Arachtober daily, but to participate as well by sharing your own images of all things eight-legged. Thank you.