The Beetle and the Bee

At the end of February, I finally found a beetle I had been looking for here, for years. Perhaps I had not been scouting for it early enough, but we barely had a winter this year, and I suspect that most years it would have been evident in March. The key was finding an aggregation of its host organism.

Tricrania sanguinipennis is a blister beetle in the family Meloidae. The adult insects measure 9-15 millimeters, but are bright enough, and active enough, that they are easily seen. Their wings, hidden under their red, leathery elytra, are almost vestigial, so they are flightless. Instead they crawl, but rather rapidly, over the surface of the soil, periodically digging where they detect the possible presence of a host.

Kansas is about as far west as this beetle is found, though there are records well north into Saskatchewan, Canada. It occurs over the eastern U.S. to extreme northern Florida, and up into adjacent southern Canada.

The limiting factor is that Tricrania sanguinipennis is a parasitoid of solitary bees that nest in dense aggregations, namely cellophane bees in the genus Colletes.

We have the Unequal Cellophane Bee, Colletes inaequalis, nesting in our yard and/or the adjacent neighbor’s lawn, depending on the year, but those locations are apparently blister beetle-free. It took finding a small aggregation of the bees in a forested park to locate the beetles.

An Unequal Cellophane Bee lurks just inside the entrance to her burrow.

The bees nest in burrows, ideally in sandy soil. The vertical, subterranean tunnels branch into several individual cells, each one an “apartment” for a single bee larva. The grub feeds on a nearly liquid loaf of pollen and nectar. The walls of its room are coated in a type of natural plastic manufactured in glands in its mother’s abdomen, which essentially waterproofs the chamber, and retards mold and fungus.

Back to the beetles. What the female beetles lack in mobility, they more than make up for in fecundity. Each lady can produce hundreds of eggs, over a thousand in some documented instances. How, then, do the beetles gain entry into these tunnels? The answer is that they do not. The larvae do.

The larval stage is unusually lengthy, progressing through six instars. An instar is the interval between molts. It is also strange in that it includes hypermetamorphosis. In this case that means the larval form changes radically in both appearance and behavior from one molt to the next.

Several male Unequal Cellophane Bees waiting for females to emerge.

The first instar larva that emerges from the egg is a sleek, streamlined, highly mobile bee-seeking missile called a triungulin. At the time they are active, it is almost exclusively male Colletes bees that are active, buzzing about and frequently landing to investigate a potential site where a female could emerge. It is at these brief moments when a blister beetle triungulin scampers aboard, affixing itself to the hairs on the underside of the bee’s abdomen.

Oops! An overeager male mistakes another male for a female.

When the male bee at last is able to mate, the triungulin transfers to the female bee. In at least a few instances, the triungulin may attach directly to a female bee that it encounters on the ground. She will eventually, and unwittingly, ferry that parasite, and probably several others, to her new nest burrow. Once inside, it disembarks and infiltrates one of the subterranean nest cells.

The beetle larva usually consumes the egg of the host immediately, but not always. The bulk of its diet will be the honey and pollen left by the bee for its offspring in the cell. It may be a frequent occurrence that more than one beetle larva invades a single bee cell. In that event, cannibalism of the competition resolves the conflict.

The meal of the host egg or larva is usually enough nutrition to trigger the beetle larva’s molt to the next instar. This results in a shocking change from that sleek, active larva into the insect equivalent of a couch potato. The second instar is, shall we say….rotund, and boat-shaped. It commences feeding on the pollen and nectar stores in the cell of the now missing bee offspring. The insect retains this form for the remainder of its larval life. The first three instars shuck their old exoskeleton completely, but the fourth and fifth instars retain each molt in its entirety. Think of it as an object inside a balloon (inside another balloon by the fifth instar). Those larvae actually shrink in size to fit inside the shed “skins.” When molting into the pupa stage, the sixth molt is again broken during shedding, and compacted at the rear of the pupa, which is still inside those other exoskeleton balloons.

It takes until late summer or early fall for the life cycle to complete, the adult beetle remaining encased in its final one or two larval exuviae, where it overwinters, still inside the cell in the host’s nest burrow.

You would think that the bee species hosting this diabolical beetle would be decimated by it, but such is not the case. Each spring there are plenty of the adult bees. What is more of a threat is the potential disconnect between the bees and their nectar plants. Colletes inaequalis visits flowering trees almost exclusively, especially Eastern Redbud, and maple trees. As the phenology of the blooming cycles becomes increasingly unpredictable thanks to climate change, the appearance of the flowers may cease to always coincide with the emergence of the bees that pollinate them.

Sources: Messinger Carril, Olivia, and Joseph S. Wilson. 2021. Common Bees of Eastern North America. Princeton, NJ: Princeton University Press. 286 pp.
Parker, J.B. and Adam G. Boving. 1925. “The Blister Beetle Tricrania sanguinipennis - Biology, Descriptions of Different Stages, and Systematic Relationship,” Proc U.S. Nat. Mus. 64(2491): 1-40. This is a wonderfully exhaustive article, with illustrations of all larval instars.

Louse Flies? Are You "Ked"-ing Me?

Until recently, insect diversity here along the Front Range of Colorado this spring has been suppressed by cool, wet weather. How amazing, then, that I should see not one, but two specimens of an insect I had seen only once or twice in all my years. I am speaking of "louse flies" in the family Hippoboscidae.

Back at the end of December in 2009, I volunteered to do a guest blog for my good friend Dave Small after he sent me an e-mail inquiring whether I might know the identity of an insect in an image he attached with his message. I didn’t quite understand the story at first, like why two hunters were involved, and why the insect was adhered to hard candy. The image was clear enough, though, that I could tell what the creature was, and that this was not a tall tale evolved from heavy drinking. Here is the rest of that piece.

Deer and related animals play host to a variety of parasitic invertebrates, including the familiar, slow-moving ticks. Such blood-feeding creatures are quick to abandon a deceased host, however, and so animals harvested during the hunt often yield some strange, living cargo during inspection and dressing.

The specimen discovered by these two hunters is an insect known as a “louse fly,” among the most peculiar of insect parasites. They are much more nimble than ticks, dodging attempts to catch them as they skirt through a host’s fur. Their flattened shape, top to bottom, and talon-like claws enhance their ability to slip between hairs and grip the hide of the host, avoiding licking and biting efforts to dislodge them.

Members of the fly family Hippoboscidae, most known louse flies are actually parasites of birds. The most infamous member of the family, though, is the “sheep ked,” well-known to those who manage flocks of ovine livestock. The adult flies are wingless, but they find each other easily for mating when the host animals crowd together.

Back to the specimen the hunters found, and collected by sticking it with a piece of hard candy. That would probably be a “deer ked,” Lipoptena cervi. Here is a terrific image of a related species, Lipoptena depressa from northern California. Both species have a life history that is typical of the entire family of louse flies, but truly mind-blowing compared to other insects.

Female louse flies do not lay eggs. They grow one offspring at a time, within their bodies, much like mammals. A single larva develops inside the equivalent of a uterus, feeding from a “milk” gland. When mature, it is “born alive,” dropping to the ground where it immediately buries itself and pupates. An adult fly emerges weeks later. Deer ked are winged, at least initially, but females that have found a host will break off their wings, the better to maneuver through the dense, coarse hair of their host.

Wingless deer ked after two days in captivity

While keds are known to transmit certain diseases from host to host, they are for the most part not economically important. Consequently, little is known about them. Kudos to our hunter friends for bringing this one into the spotlight.

The first specimen I found this year landed on my while I was hiking in Aiken Canyon Preserve off of highway 115, about fifteen miles northeast of Penrose, Colorado on Memorial Day (May 30). I recognized it fast enough to grab it while it was tangled up in some of my sparse arm hair.

After chilling the tiny, 3 millimeter creature in the fridge for a few minutes, I dumped it out into a casserole dish to photograph it. Well, it was apparently completely unaffected by the cold and flew off after I fired off only a couple of legible shots. About 30-45 seconds later, from out of nowhere, it landed on my chest. I guess it pays to be a mammal to keep these flies under some degree of control. A couple of days later, I found the fly had self-broken its wings, such that they were mere stubs. Despite that, the insect was still highly mobile and most of my shots were as blurry as when it had flight capability.

The next encounter was at a blacklight set up to attract moths in Cheyenne Mountain State Park on the night of June 4. I routinely scrutinize the most minute of creatures in the event they may be of interest, and much to my surprise there was another "ked." It, too, was fully winged but, perhaps mesmerized by the ultraviolet light, sat motionless and allowed me to take multiple images....most of which are still not optimal because the blame bug is so miniscule.

Want to find your own louse flies? You might volunteer to go hunting game mammals and birds with your friends to get a chance at shaking one loose. Otherwise, good luck. These insects are common, but so seldom stray from hosts that it is sheer serendipity to stumble across one. More than likely, the fly will find you.

A Bed Bug Primer

”Sleep tight, don’t let the bed bugs bite.” That rhyme had no relevance for decades, but not any longer. After vanishing from the scene after World War II, bed bugs are back in our nightmares and, more importantly, our reality. Thankfully, bed bugs pose no threat from the transmission of blood-borne pathogens, but what they lack in virulence is more than made up for in litigations. Here is what you need to know about these insidious pests.

What is a Bed Bug?

Cimex lectularius is a member of the family Cimicidae in the order of true bugs (Hemiptera). Like all true bugs they have piercing-sucking mouthparts. Bed bugs use their beaks to drink the blood of human beings. Yes, we are the preferred host of this parasitic insect. Pets, other mammals, and birds suffice in a pinch for starving bed bugs, but people are the real target.

These are small, wingless insects, dorso-ventrally flattened (top to bottom) to the point of being paper thin. Adults measure only 4-6 millimeters, 7-8 millimeters immediately after feeding. First instar nymphs (those just emerged from the egg) are only one millimeter, and so pale as to be nearly invisible on the typical mattress or sheet.

First instar bed bug nymphLife Cycle

Bed bugs go through five instars before becoming adults. An instar is the interval between molts. Each bed bug must have one blood meal in order to graduate from one instar to the next.

Bed bugs of various instars

Eggs usually hatch 6-10 days after being laid, though it can take up to 21 days. Each nymph stage lasts about one week under ideal conditions, longer if blood meals are irregular. Adult bed bugs typically live ten months to a year, feeding about every ten days. Since the average female can lay 500 eggs in her lifetime, you can imagine how quickly a population of bed bugs can build.

Second or third instar nymphDo I Have Bed Bugs?

Obviously, inexplicable bite wounds can be a clue that you might have bed bugs. Bites are typically in a linear arrangement of three, evidenced as red, slightly-raised welts. However, some people do not react at all to bites, while others experience worse symptoms. If your bedmate complains, take them seriously.

A fair-sized population of bed bugs gives off a sweet, distinctive odor, so use your sense of smell. The French word for bed bug is punaise, a reference to this stinky aspect of bed bug biology.

If you suspect bed bugs, strip the bed and look for the insects and their signs, especially along mattress seams, under mattress buttons, the slots where the bed frame attaches to headboard and footboard, and other tight spaces. Bed bugs have to poop, and reddish or dark brownish stains are another sign of their presence.

Avoiding Bed Bugs

Inspect, inspect, inspect! You cannot be too careful in avoiding infestations. When traveling, inspect your lodging thoroughly, and elevate your luggage off the floor. Maybe put the suitcase in the bathtub. Look behind headboards that are flush against the wall. Take drawers out of the nightstand and examine them carefully. Look under carpet where it goes up the wall like a baseboard. Look in mattress seams and under mattress buttons.

Any place where there is serial occupancy is prone to infestations, from five star hotels to rental cabins, dorms, prisons, hospitals, movie theaters, planes, trains, buses, taxicabs….

Beware of secondhand furniture and avoid used mattresses. The rise in popularity of thrift stores is credited in part with expanding the bed bug empire, so again, inspect items thoroughly before purchasing.

Treating for Bed Bugs

Don’t panic, but do seek professional help. Bed bugs are extremely difficult to eradicate, so find a reputable, recommended company that has a successful track record. Understand that the extermination process is highly invasive. Furniture will have to be taken apart, perhaps even discarded. Your best bet may be heat treatment. Unfortunately, this is usually the most expensive option, but it is highly effective.

Complications may arise if you are in a multi-family dwelling, rental, or are the proprietor of a hotel, motel, campground, or other lodging enterprise. This is when legal representation is often sought to determine (or avoid) liability. Do make sure your interests are protected, but try to refrain from making any situation more adversarial than it already is.

Sources: Berenbaum, May R. 1989. Ninety-nine Gnats, Nits, and Nibblers. Urbana: University of Illinois Press. 263 pp.
Centers for Disease Control and Prevention. 2013. Parasites – Bed Bugs
Maestre, Ralph H. 2011. The Bed Bug Book. NY: Skyhorse Publishing. 181 pp.
National Institutes of Health. 2014. “Bedbugs,” Medline Plus.

Ibaliid Wasps

I am constantly surprised. I am also fortunate to have an extra set of keen eyes whenever my wife and I go exploring together. The evening of June 9 we decided to enjoy Sinton Pond Open Space here in Colorado Springs. While trying to get a picture of a damselfly, Heidi spied something even more interesting: a sleeping wasp in the family Ibaliidae.

I know, I’d never heard of them, either, at least until I found a specimen in Cincinnati when I lived there. I tried to turn it into some kind of ichneumon wasp, but it simply didn’t fit any of the characters for Ichneumonidae. I don’t recall how I finally found the answer, but I was certainly shocked to learn its nearest relatives are gall wasps.

There is one genus, Ibalia, in North America, with six species, the most widespread of which appears to be Ibalia anceps. Its distribution extends from Nova Scotia, Ontario, and Wisconsin south to Florida and Texas and west to Colorado. Geographic variation accounts for different color patterns in the wings. Ibalia anceps adults fly mostly in late May and early June.

Ibalia are parasites of horntail woodwasps in the family Siricidae. The female wasp lays an egg on the horntail grub, which is inside a dead, dying, or weakened deciduous tree, such as hickory. The larva that hatches from the ibaliid egg then penetrates the cuticle of the horntail larva and begins feeding as an internal parasite. Later, as the larva grows, it exits the host and finishes feeding as an external parasite.

Here locally, the only common horntail is the Pigeon Tremex, Tremex columba, so that must be the host. Indeed, elsewhere across its range, I. anceps is associated most often with T. columba. Please see my post on the Pigeon Tremex for more information about that wasp.

Ibaliids may be recognized by the laterally compressed abdomen. The abdomen is so thin that it conveys the impression that the rear end of the insect was smashed between the pages of a heavy book. Male Ibalia have fifteen segments in each antenna, while females have only thirteen segments. Females also possess an ovipositor (egg-laying organ). Specimens average about 12-14 mm in length, which is gigantic compared to their tiny relatives in the superfamily Cynipoidea, most of which are around three millimeters.

Keep your eyes open for these unique wasps. Take images if you are able, and share them with other naturalists and entomologists.

Sources: Goulet, Henri and John T. Huber (eds.) 1993. Hymenoptera of the World: An identification guide to families. Ottawa: Agriculture Canada. 668 pp.
Nendick-Mason, Hannah, et al. 2006. “Species Ibalia anceps,” Bugguide.net.
Smith, David R. and Nathan M. Schiff. 2002. “A review of the siricid woodwasps and their ibaliid parasitoids (Hymenoptera: Siricidae, Ibaliidae) in the eastern United States, with emphasis on the mid-Atlantic region,” Proc. Entomol. Soc. Wash. 104(1): 174-194.

Wasp vs. Wasp

My wife and I went down to Fountain Creek Regional Park in Fountain, Colorado recently (the evening of June 2, 2013), and I happened upon an interesting scene. About five or six female mason wasps, Symmorphus sp., were nesting in beetle borings in a cottonwood log by the side of the trail. About four cuckoo wasps, Chrysis sp., were hanging out around the holes the wasps were using as nests. Heidi said I must have spent 45 minutes taking pictures of them all, but it was worth it because I got to observe what was happening.

The above image is one of only two really nice shots I got of the female Symmorphus mason wasps. They would alight near their nest hole, and dive in very quickly. If I approached too quickly with the camera, the wasp would fly off before entering. If I waited too long, I would get a shot of the wasp’s abdomen disappearing, or a seemingly empty hole. Waiting for the wasp to emerge was basically futile, as she would exit much more quickly than was possible to focus.

You have to have an appreciation of the size of the players and the beetle borings to know what I was up against. The borings are probably the exit holes of deathwatch beetles, family Anobiidae, which bore in dead, solid wood as larvae. The diameter of each hole is about the same as the end of a retracted ballpoint pen (about 3 millimeters). Yes, both the mason wasps and cuckoo wasps could fit through those holes.

”Science has strict rules against anthropomorphism, but if you ask me, those chrysidids were cunning and calculating.”

Meanwhile, the bright metallic green cuckoo wasps were not as easily disturbed as the mason wasps. They might run randomly around between holes, but most of the time they sat quietly in the vicinity of a group of holes. Science has strict rules against anthropomorphism, but if you ask me, those chrysidids were cunning and calculating. They were waiting for the wasps to show them which holes were active nests worthy of their attention.

Cuckoo wasps are parasitic in the nests of other solitary wasps. They can’t sting, but the last few segments of the abdomen of the female telescopes into an egg-laying organ that can reach into the bottom of one of those nest tunnels. The cuckoo wasp lays an egg in the nest of its host, and the larva that hatches generally consumes the meal intended for the host offspring.

In the case of Symmorphus, females catch and paralyze leaf beetle larvae that are free-living, or are leaf-miners (living between the layers of a leaf). At least one species of Symmorphus attacks leaf-mining moth caterpillars on occasion. The larval victims are packed into a cell along the length of the beetle boring, and the mother wasp lays her own egg on the last victim. She then creates a partition of mud or chewed wood fibers, and begins a new cell. The process is repeated such that several cells usually occupy one tunnel.

The mason wasps, for their part, were also quite cognizant of the cuckoo wasps. I witnessed at least one altercation whereby a female mason wasp fended off a too-eager chrysidid at the entrance to her nest. Cuckoo wasps, while they can’t sting, have a dense, pitted exoskeleton that effectively repels the bites and stings of their hosts. They can even roll into a ball as a last resort, becoming virtually impregnable.

Without collecting specimens of the wasps, which I did not do, I cannot conclude the species I was observing. Process of elimination narrows the possibilities to Symmorphus cristatus or S. canadensis for the mason wasps. The cuckoo wasps could represent one or more species in the Chrysis coerulans species group. Scientists are still trying to sort out how many species there actually are in that complex.

After getting up from my baseball catcher’s stance, I could feel how my legs had stiffened. The pain was worth the gain, though, and I encourage my readers to endure for the sake of personal and collective knowledge. Field observations are not the scientific priority they once were in the fledgling years of ethology (study of animal behavior). It could easily be you who makes history with a new host record for a predator or parasite, or records some other hitherto unknown association between species.

Sources: Bohart, R.M. and Lynn S. Kimsey. 1982. “A Synopsis of the Chrysididae in America North of Mexico,” Mem. Am. Entomol. Inst. 33: 1-266
Buck, M. Marshall, S.A., and Cheung, D.K.B. 2008. “Identification Atlas of the Vespidae (Hymenoptera: Aculeata) of the Northeastern Nearctic Region,” Canadian Journal of Arthropod Identification No. 5: 492 pp.
Krombein, Karl V. 1967. Trap-nesting Wasps and Bees: Life Histories, Nests, and Associates. Washington, DC: Smithsonian Press. 570 pp.

Ticks

It is often assumed that entomologists and arachnologists find no kind of arthropod to be revolting; that we never swat a mosquito, and that we vigorously advocate that the public refrain from bringing purposeful harm to any of the six- or eight-legged. Well, we have our limits. While I have a mild fascination with ticks, I don’t tolerate their presence on my body, my pets, or anyone else’s for that matter. There are good reasons to be vigilant when it comes to these parasitic mites, and Lyme Disease is only one. Bites from ticks can result in a variety of illnesses, including “heartland virus,” discovered earlier this year.

Male American Dog Tick

Tick types
North American ticks fall into two basic categories: Hard-bodied ticks, family Ixodidae, and soft-bodied ticks (Argasidae). Soft ticks are encountered infrequently, most species being associated with the burrows and nests of rodents, or with bats. A few are hosted by deer and livestock. Hard ticks are abundant, widespread, and nearly impossible to avoid.

Soft-bodied tick, Arizona

Tick biology
Ticks have a life cycle consisting of four stages: egg, larva, nymph, and adult. Larvae have only six legs, and are often referred to as “seed ticks.” The larva takes one blood meal from a host, then drops off the animal. It molts into an eight-legged nymph in about one week. The nymph locates a host and feeds, drops off, and molts into either another nymphal stage or an adult. Adult ticks are sexually mature specimens, whereas the preceding life stages are not.

"Questing" wood tick, California

Ticks find hosts by a behavior known as “questing.” The tick climbs to the tip of a grassblade, leaf, or other object and perches with front legs outstretched. Special sense organs in the legs detect carbon dioxide breathed out by vertebrate animals. Additional sensory organs hone in on odors and body heat. Ticks usually grab a passing host, but they can quickly crawl 10-15 feet to reach a source of carbon dioxide, such as a grazing deer.

Embedded tick nymph

How ticks attach
Ticks bite with mouthparts that, under high magnification, resemble a Swiss army knife of sawblades. The paired chelicerae (“jaws”) saw into the skin of the host, and later tear into tiny capillaries to get the blood flowing. The central, harpoon-like mouthpart is called the hypostome, and that is the tube the tick uses to inject saliva and anti-coagulants, as well as siphoning the blood of the host. The chelicerae anchor the tick in place, but the tick also secretes a glue-like substance that hardens around the entire apparatus. No wonder ticks are so hard to remove once they lodge themselves into a person or pet.

Engorged female American Dog Tick

Tick feeding and reproduction
The exoskeleton covering the abdomen of a female tick is deceptively thick, leathery, and wrinkled, but capable of unbelievable expansion to accommodate a gut that swells with blood. She may balloon to twenty or fifty times her normal size, and up to 200 times her original weight before feeding. She needs the nourishment to produce her eggs….

And ticks are nothing if not prolific. Mating may take place before or after feeding, and on or off of a host. Females are typically larger than males, and often marked more ornately. The two genders find each other through pheromones, chemical scents emitted into the air. Each mated female lays large masses of eggs, some containing up to 20,000 ova. The eggs may be laid on or off of a host.

Blacklegged Tick, © Karl Hillig via Bugguide.net

Deer Ticks
The tick that most often makes the news is the Blacklegged Tick, Ixodes scapularis (formerly known as I. dammini). This is the “deer tick” that vectors Lyme disease, named for the town of Old Lyme, Connecticut where it was first discovered in 1975. The disease was actually known from Europe as early as 1910, where it went by the name erythema migrans, roughly translated to “migrating red rash.” The organism that causes the disease is a spirochaete bacterium, Borrelia burgdorferi.

I won’t go into the particulars about Lyme disease, as there are plenty of other resources available. Contrary to popular belief, only the adult ticks feed on larger mammals like deer. The larvae and nymphs are hosted by birds and rodents. Increasingly, all host reservoirs are becoming more and more adapted to urban and suburban habitats, increasing human exposure to their pathogens and parasites. The Blacklegged Tick is also a vector of babesiosis; and its bite can cause tick paralysis.

The Western Blacklegged Tick, Ixodes pacificus, is the only other known carrier of Lyme disease. Incidences of the disease in west coast states, Utah, southern Nevada, and northwest Arizona are likely attributable to this tick species.

Heartland virus was discovered earlier this year in northwest Missouri. Initially, two patients were thought to be victims of ehrlichiosis, another tick-borne disease, but the patients failed to respond to treatment. Ticks have not been identified conclusively as the vectors of Heartland virus, merely implicated thus far. Deer ticks are substantially smaller than the next two species discussed here.

Female Lone Star Tick

Male Lone Star Tick

Lone Star Tick
Lyme and Heartland may make headlines, but ticks are responsible for a surprising array of medical problems. I recently visited Missouri with my wife, and we were both plucking ticks off ourselves and each other. The first ones I found were Lone Star Ticks, Amblyomma americanum. Females are easily recognized by the bright yellow or ivory spot on their backs. Males are smaller, with a few pale spots along the margin of the abdomen. This tick is well known as a vector of ehrlichiosis, tularemia, and Southern Tick-associated Rash Illness (STARI). It has also been implicated in the transmission of tick paralysis, and suspected as a vector of Q-fever. White-tailed deer are the principal host of all life stages of the tick, though larvae and nymphs are also found on birds.

Male American Dog Tick

Wood Ticks
The other tick we found was the ubiquitous American Dog Tick, Dermacentor variabilis. We even pulled one off of our dog, who we had left with relatives in Kansas for a short time. Rocky Mountain Spotted Fever and tularemia are carried by this species. Tick paralysis is another malady caused by this species, and it is also a suspected carrier of ehrlichiosis. Larvae and nymphs of the American Dog Tick feed on small rodents, while the adults are hosted mostly by medium-sized mammals.

Ticks and pets
It is important to note that Fido can suffer from Lyme disease, too, and also anaplasmosis, another tick-borne ailment attributed to Blacklegged Ticks. Ask your veterinarian for the best ways to keep your pet from getting ticks.

Inspecting for ticks; and preventing them
Ticks have an uncanny ability to remain undetected until they find a spot to feed. Most people cannot feel a tick crawling on their body. Furthermore, ticks have a nasty habit of attaching in places you can’t readily see yourself: the small of your back, behind your knees, or behind your ears. It is recommended that you ask someone to help inspect you for ticks as soon as possible after an outdoor trek where ticks are likely to be found.

You can try to prevent ticks by wearing a longsleeve shirt, tucked into your pants, and with cuffs that fit tightly around your wrists. Long pants, the cuffs tucked into your boots, will help keep ticks at bay, too. Light-colored clothing is best because ticks are dark and more easily visible on beige or other pale colors. Insect repellants with DEET as the active ingredient have at least some efficacy in protecting you from ticks, but apply them correctly according to label instructions.

Female Lone Star Tick

Sources: Drummond, Roger. 1998. Ticks and what you can do about them (2nd edition). Berkeley: Wilderness Press. 74 pp.
Centers for Disease Control. “Ticks”

Wasp Wednesday: Carrot Wasps

Around the holidays, we humans tend to pack on the pounds as we indulge in feasts and parties at Thanksgiving and Christmas. Wasps do not have this problem. One family of wasps in particular manages to stay super-slim and slender: the Gasteruptiidae or “carrot wasps.”

There are at least fifteen species of carrot wasps in North America, all in the genus Gasteruption. Five of those occur in the eastern U.S. and Canada. At first glance, they might be mistaken for ichneumon wasps, or even sphecid wasps in the genus Ammophila. This is probably not coincidental, since carrot wasps do not sting, but could benefit by looking like other wasps that can sting.

You can easily identify carrot wasps by the following characters:

• Pronounced “neck” between head and thorax.
• Abdomen attached high up on the thorax, not between hind legs.
• Hind tibiae swollen (think “leg warmers”).
• Antennae with 13 segments (male) or 14 segments (female). Ichneumon wasps have far more antennal segments.
• Ovipositor sometimes with a white tip

Species identification often hinges on the texture of various parts of the thorax; and to a lesser degree on color pattern.

These are not terribly large insects, from 13-40 millimeters depending on the species, and much of that length owing to the long ovipositor in females. They are so skinny they remind one of a flying needle.

The adult wasps are most often encountered at flowers, especially those umbelliferous blooms in the parsley family, hence their common name of “carrot wasps.” I have also seen them at White Sweet Clover (Melilotus alba) and Desert Broom (Baccharis sarothroides), and Leafy Spurge (Euphorbia esula). Flight activity seems to peak in late spring (latter half of May) and/or mid-summer (July).

male

The biology of gasteruptiids is rather poorly known, but so far our North American species appear to be parasites of solitary bees and wasps that nest in twigs or borings in wood. The female wasp needs her long ovipositor to reach the depths of a host’s tunnel and deposit an egg. The larval carrot wasp that hatches usually feeds on the pollen, nectar, or prey stored as food for the host larva, rather than the host larva itself.

Trap-nesting for solitary bees and wasps could easily reveal many more host records for Gasteruption wasps, if one keeps careful notes.

Sources: Jennings, John T. and Andrew R. Deans. 2006. “Gasteruptiidae,” The Tree of Life Web Project, Version 22.
Smith, David R. 1996. “Review of the Gasteruptiidae (Hymenoptera) of Eastern North America,” Proc. Entomol. Soc. Wash. 98(3): 491-499.
Townes, Henry. 1950. “The Nearctic Species of Gasteruptiidae (Hymenoptera),” Proc. U.S. Nat. Mus. 100(3259): 85-145 (Note that this reference includes what is now the family Aulacidae).

Wasp Wednesday: Dasymutilla bioculata

Last Sunday I wrote about a brightly-colored jumping spider, Phidippus apacheanus, and suggested that it was probably a mimic of wingless female wasps called velvet ants. Today I would like to introduce you to one of those wasps. Velvet ants comprise the family Mutillidae, and can be found across most of the North American continent. They are most common in arid habitats like deserts and prairies. Here in Colorado Springs, Dasymutilla bioculata is one of the most frequently encountered species.

Many velvet ants are bright orange, red, or yellow, and black. This pattern advertises the fact that females can sting. So powerful is that sting that one of the larger species is called the “cow killer.” Folklore has it that the pain is enough to kill livestock. It is no mystery why less well-defended insects, or spiders, would want to look like velvet ants. No sensible predator wants to mess with them.

I have seen female Dasymutilla bioculata scurrying over sandy paths in open fields, usually on overcast days or around dusk when the air temperature begins to cool slightly. Both genders like to clamber around on the stems and leaves of Common Sunflower, Helianthus annuus. They find the sweet, sticky secretions of the plant to their liking.

Male velvet ants have the customary two pairs of wings and fly well, but they can also be colored very differently from their female counterparts. This has resulted in much confusion, even among experts who seek to associate the males with the appropriate females and vice versa.

Dasymutilla bioculata is an excellent example of “lumping,” whereby scientists decide that several different species are actually variations of just one species. A paper published in 2010 resulted in lumping no fewer than twenty-one former species and subspecies under the name Dasymutilla bioculata. The authors of the publication used molecular analysis to find common nuclear ribosomal RNA markers among all the former species and subspecies. Morphological differences (what you see when you look at the external structure of the insects) were deemed too inconsistent to be the sole determining factors in differentiating species.

No wonder I didn’t recognize these Colorado specimens. George Waldren, a velvet ant expert and volunteer editor at Bugguide.net was kind enough to set me straight, identifying my images of the females. The images of the male shown here may or may not be the same species. You just can’t tell from images alone.

Dasymutilla bioculata ranges across the entire continent, and from southern Canada to Mexico. Adults vary in size from about 8 millimeters to 16 or 17 millimeters in body length. The bigger the specimen, the better it fed as a larva.

The life histories of velvet ants are often as mysterious as their classification, or simply unknown. Those species we do know well are parasitic on other insects, especially other solitary wasps and bees. Female velvet ants scour the ground for signs of their hosts, which often dig burrows in the soil. Velvet ants can even detect closed burrows, digging them open to gain access. Once inside, the female lays an egg in the cell or cells at the end of the underground tunnel. The larval wasp that hatches will attack the pupa of the host, or a larva in diapause (inactive state).

The known hosts for Dasymutilla bioculata are sand wasps in the genera Bembix and Microbembex. Should an adult sand wasp discover a velvet ant invading her nest, she will of course attack it. Velvet ants have an extra-thick exoskeleton that effectively deflects the bites and stings of their enemies.

I would advise anyone searching for velvet ants to avoid picking them up. Do scoop one into a vial some time and put it up to your ear. Do you hear that? Both genders of these wasps can “squeak” by rapidly rubbing their abdominal segments together. Music to my own ears anyway.

Sources: Kits, Joel, et al. 2011. “Species Dasymutilla bioculata,” Bugguide.net.
Krombein, Karl V. and Paul D. Hurd. 1979. Catalog of Hymenoptera in America North of Mexico. Washington, DC: Smithsonian Institution Press. 2188 pp.
Williams, K.A., D.G. Manley, E.M. Pilgrim, C.D. von Dohlen & J.P. Pitts. 2010. “Multifaceted assessment of species validity in the Dasymutilla bioculata species group (Hymenoptera: Mutillidae). Syst Entomol, 36(1): 180-191.

Wasp Wednesday: Mesostenus

I am finding a great diversity of wasps (and other insects) visiting the leaves and stems of sunflowers (Helianthus spp.) this summer here in Colorado Springs. Among them is an ichneumon wasp in the genus Mesostenus. Boldly marked in black, white, and red, they are difficult to miss despite their small size (about 6-13 millimeters in the specimens illustrated here).

Sunflowers have special structures called “extrafloral nectaries” that secrete a sweet liquid that insects crave, especially ants. The ants try and drive off every other competing insect, which is mostly wasps, bees, and flies. Some plants are more attractive than others, and the reasons for that are probably many. We have had a sustained drought here on the Front Range, verging on the “extreme” side of the scale. Record-breaking hot temperatures have also withered many annual plants. It is metabolically expensive for sunflowers to produce the nectar, so some individual specimens probably forgo the production process. This leaves them at least slightly more vulnerable to herbivorous insects that the ants would normally fend off along with the flies and wasps.

Because the wasps are constantly dodging the ants, it is difficult to get good images of them. They are persistent, however, and may eventually settle down long enough for me to get a clear shot while they lap up the sunflower’s exudates. At least it is easy to tell the difference between the females and males. Mesostenus is one of the many genera in the Ichneumonidae where the female possesses a long, tail-like egg-laying organ called an ovipositor. Males (below) lack an ovipositor, obviously.

Many people mistake the ovipositor for a stinger, and react with alarm to a wasp that looks like it could penetrate a down jacket with its venomous weapon. The device is instead employed to lay eggs in the host insects the wasps parasitize.

There are ten species of Mesostenus in North America north of Mexico, but the genus is nearly worldwide in overall distribution. About four of those species can be found in Colorado. M. sicarius is closely tied to certain cacti (Opuntia spp.), of which we have prickly-pear here in the Springs.

The long ovipositors come in handy when inserting an egg in a stem-boring or shoot-boring caterpillar like that in the genus Acrobasis, in the moth family Pyralidae. The wasps are also important parasites of stored product pests like the Indianmeal Moth, Plodia interpunctella, also in the Pyralidae. The American Plum Borer, Euzophera semifuneralis, has caterpillars that feeds beneath the bark of host trees, a habit that still leaves them vulnerable to Mesostenus gracilis, the species that might be shown here. Not surprisingly, the caterpillar of the Sunflower Moth, Homoeosoma electella, is also a host. Mesostenus also parasitizes caterpillars of the moth families Crambidae and Tortricidae.

We only know host associations for a few of these wasps, so rearing caterpillars may yield new host records. That is true for other Ichneumonidae as well. Folks who try raising caterpillars through to moths or butterflies are often profoundly disappointed when a wasp (or fly) emerges from the larva or chrysalis instead. I urge people to take care to preserve the insect anyway, noting the species (or genus or family) of caterpillar from whence it came. It could turn out to be a valuable observation.

Sources: Carlson, Robert W. 2009. “Database of Hymenoptera in America North of Mexico,”Discover Life.
Cushman, R.A. 1929. “A Revision of the North American Ichneumon-flies of the Genius[sic] Mesostenus and Related Genera,” Proc U S Nat Mus 74(2761): 1-58 (Smithsonian Digital Repository, available as a PDF).