Computer Woes

I regret to inform my loyal readers here that I am having serious computer issues. I am writing this from my wife's machine, and plan to take my own computer to the repair shop ASAP. That might be Monday at the earliest, and how long they will need it I have no idea. Hoping my disk isn't bad, but it is a relatively "old" HP Premium Elite HPE I purchased back in....2010?

I've backed up all my edited images, documents, etc, but I have thousands of unedited photos that I don't have room to back up on my external hard drive. So, I will still be able to do some blogs in the future, even if I face the worst-case scenario. I just really hope that doesn't happen.

Thank you for your understanding and patience during this trying period. I will not be posting for the immediate, foreseeable future, but have no plans to terminate the blog.

Backswimmer or Water Boatman?

Just a short post for “True Bug Tuesday,” addressing an identification problem that many people admit having. I am not an expert on aquatic insects by any means, but differentiating backswimmers (family Notonectidae) from water boatmen (family Corixidae) is fairly straightforward.

Backswimmer swimming upside down

My own experience has shown that backswimmers are generally far more commonly seen by the casual observer than are water boatmen. Backswimmers can even turn up in the fountains, swimming pools, and other artificial water environments water boatmen rarely frequent. Now, if you bother dragging a net through the water, especially over the bottom of a pond or slow-moving stream, then you may see water boatmen at least as frequently as backswimmers, if not more so.

Turn on lights at night anywhere near water and you may bet large numbers of water boatmen showing up, flailing about on the ground. Both water boatmen and backswimmers can fly as adults, but backswimmers seem to be mostly diurnal and will rarely if ever be attracted to lights at night.

Water boatman attracted to light at night

Physically, both kinds of insects do superficially resemble each other. Both are more or less oval or bullet-shaped, and the hind legs are very long, modified for rowing through the water. That is pretty much where the similarities end, however.

Adult backswimmers, at least those of the common genus Notonecta, are much larger than the average water boatman. Backswimmers, in cross section from front to back, have distinctly triangular bodies. They are shaped more like a boat than a water boatman. The top of a backswimmer is keel-like, affording it the ability to swim very rapidly upside down. Water boatmen are more flattened top to bottom.

Water boatman

The front legs of backswimmers are short, but shaped normally, with no obvious modifications. The front legs of water boatmen have spoon-shaped tarsal segments for scooping organic matter into the mouth of the bug. While backswimmers have a four-segmented rostrum (“beak”) they use to bite prey, water boatmen have the beak fused to the head. The face of a water boatman reminds one of an imperial storm trooper from Star Wars.

Water boatman. Note scoop-like front "feet"

Most water boatmen are brown on top, marked with fine, transverse black lines, giving them a slightly corrugated appearance. Backswimmers, by contrast, are usually boldly marked with patches of black, yellowish-brown, red, or white.

Top of backswimmer, © Lynette Schimming

Backswimmers frequent open water where they actively pursue mosquito larvae and other small aquatic insects. Water boatmen normally cruise the bottom, stirring up muck and microscopic organisms that they feed on. Consequently, water boatmen are often difficult to see when you are looking into the water. They are camouflaged, and/or they hide under leaf litter and other bottom debris.

Backswimmer, © Margarethe Brummermann

Look for backswimmers surfacing to take in air with those hydrophobic hairs around their rear end. The hairs also go down the middle of the underside of the abdomen, helping to trap air for their underwater lifestyle.

Source: Lehmkuhl, Dennis M. 1979. How to Know the Aquatic Insects. Dubuque, Iowa: Wm. C. Brown Company Publishers. 168 pp.

Termite Swarms

It is, was, or will be termite swarming time across much of North America. Contrary to popular “knowledge,” we do have termites here in Colorado, at least below 7,000 feet elevation. Our most abundant species is the Arid-land Subterranean Termite, Reticulitermes tibialis. Back on the morning of May 24, I happened upon a colony that was liberating its “alates,” winged reproductive termites that will mate with members of other colonies and begin their own new colonies.

Subterranean termites actually nest in the soil, consuming wood and other sources of cellulose that are buried in the soil or in contact with the soil. Turning back a board out in the shortgrass prairie here in Colorado Springs is likely to uncover foraging termites that quickly seek shelter back in their underground tunnels.

A typical termite colony consists of a “king” and “queen,” a male and female pair that founded the colony and bond for life. That life can be a decade or more for the queen. Her sole mission is to lay eggs, and she is a bit of a bloated creature, her abdominal segments distended. Still, she can move around rather freely, in contrast to the huge, immobile queens of some tropical termite species that exist trapped in a “royal cell” defended by soldier termites.

Soldier termite

Subterranean termite colonies have soldiers, too, with large, rectangular heads and oversized jaws they can use to dispatch ants, the chief predators of termites. Most of the colony is made up of a “worker” caste that does the foraging, underground tunnel- and above-ground tube-construction, tends the queen and newly-minted immature termites. All the young termites in the colony are workers, but have the potential to become soldiers or reproductives. In situations where a queen dies, or becomes separated from part of the colony, some workers can metamorphose into supplementary reproductives capable of laying eggs themselves within their parent colony.

Once each year, a mature colony launches a swarm of winged male and female termites that goes in search of mates in hopes of starting new colonies. Arid-land Subterranean Termites typically swarm from January to March at elevations below 4,000 feet, and in June or July above that elevation. The alates I witnessed were issuing from imperceptible cracks in the soil, like toothpaste oozing from the tube. Check out the video below:

Termite swarms are like a buffet to insectivores, and it was only a matter of minutes before tiny ants set upon the lethargic alates, carting them off by the bushel to feed their own ant larvae in some subterranean nest. Birds, amphibians, lizards, spiders, and countless predatory insects feast on the living confetti.

Ant carrying off alate termite

Those female individuals that do survive are mostly wind-blown across the landscape, hoping to land in the vicinity of an unrelated colony that is also swarming. The female sheds her wings and emits a pheromone (chemical scent) that attracts males. Once a suitable mate appears, they mate and begin searching for a nesting site. The pair creates a small chamber underground or beneath a stone or other object, and she begins laying eggs.

Alate termite with hind wings stuck together

How do you tell winged termites from winged ants? Winged termites have two pairs of wings of equal length, whereas ants have the front wings much larger than the hind wings. Ants have long, elbowed antennae, while termites have shorter antennae with segments of equal length. Ants have the body clearly divided into three sections: head, thorax, and abdomen. Winged termites have those divisions much less obvious. The thorax and abdomen seem to merge seamlessly in termites.

Pair of winged ants, Crematogaster sp.

Subterranean termites are not large insects. Even the alates of the Arid-land species measure only 10 millimeters from nose to wingtip. Soldiers are a mere 3.5-4.5 millimeters. This species occurs throughout the intermountain west of the U.S., eastward to Missouri, Arkansas, and Texas, south to Mexico. Other species of Reticulitermes range in other parts of North America.

A termite swarm outdoors, away from your own home, is a spectacle to behold. An indoor swarm….not so much. Still, to suddenly witness an enormous population of normally unseen animals erupting from the landscape is simply stunning. It helps to know that, in nature, termites are valuable decomposers that turn and aerate the soil while breaking down cellulose into nutrients now available to other living organisms.

Notes: Fairly recently (2007), termites became reclassified. Once they were members of their own order, the Isoptera. Today they are recognized essentially as “social cockroaches,” lumped with roaches in the order Blattodea.

Termites, unlike carpenter ants that merely chew cavities in wood to make nesting space, actually do eat wood. They can do this thanks to a gut fauna of microbes that efficiently break down cellulose. The bacteria, archaea, and protozoans exist only inside of termites, and are acquired by young termites when they consume fresh fecal material of adult termites, or are fed regurgitated, partially-digested food by worker termites.

Sources: Cranshaw, Whitney and Boris Kondratieff. 1995. Bagging Big Bugs. Golden, Colorado: Fulcrum Publishing. 324 pp.
Helfer, Jacques R. 1972. How to Know the Grasshoppers, Cockroaches, and Their Allies (2nd edition). Dubuque, Iowa: Wm. C. Brown Company Publishers. 359 pp.
Noll, Kenneth. “NSF Termite Project,” Noll Lab.
”Termites Are Cockroaches After All,” Natural History Museum (London) News.

Eyed Elaters

I am almost guaranteed to get at least one query every year about a large beetle with enormous eyes. The “eyed elaters” in the genus Alaus, family Elateridae, certainly are a curiosity, and thankfully harmless. This past week my wife and I were fortunate enough to encounter two specimens of the Eyed Click Beetle, Alaus oculatus, while we were in Georgia, just outside of Atlanta.

Alaus oculatus

There are currently six recognized North American species in the genus Alaus, five of which are discussed below. They are collectively found over most of the U.S. and southern Canada. All are large insects, active during the day or at dusk, and are strong fliers. Ironically, they seem far less ambulatory on their six legs. They are usually seen on logs, stumps, or tree trunks where they are surprisingly cryptic given their large size and striking eyespots. A motionless eyed elater is often nearly invisible.

Alaus oculatus from Georgia

Alaus oculatus varies from 24-44 millimeters in length, is bullet-shaped, and mottled black and white. This is the species most commonly encountered species in eastern North America, found from Quebec and Ontario south and west to Texas, the Dakotas, and eastern Colorado. They are sometimes attracted to aromatic solvents and fresh paint, scents that are also produced by freshly cut or downed trees.

Larvae of all Alaus species live in decaying wood where they prey on the larvae and pupae of other kinds of beetles. These giant “wireworms” have strong jaws and should be handled carefully, if at all.

Likely a young Alaus sp. larva

The “Blind Click Beetle,” A. myops (not illustrated), has much smaller eyespots than its cousin, and is mostly slate gray in color. Adults measure 19-42 millimeters. This is insect is most common in southern pine forests, but ranges from Quebec to Florida and west to Manitoba, Minnesota, Kansas, and Texas. Both adults and larvae are predatory and are found under loose bark on pine trees, logs, and stumps.

The western half of the continent has its own set of eyed elater species, including the Western Eyed Click Beetle, A. melanops. Its geographic distribution includes British Columbia, Oregon, Colorado, California, and New Mexico. Adults measure 20-35 millimeters. They resemble the Blind Click Beetle, but the ranges of the two species do not overlap.

Alaus melanops

Perhaps the most spectacular eyed elaters reside in the southwest U.S. The Zuni Click Beetle, A. zunianus, appears confined to Arizona. Note the eyespots are rounder than in other Alaus species, and the mottling is ivory or beige rather than stark white in many specimens. These are hefty insects, more robust than the others discussed so far.

Alaus zunianus

The Texas Click Beetle, A. lusciosus, is nearly identical to the Zuni Click Beetle, but it ranges from Texas to southern Colorado, Oklahoma, and Kansas.

Click beetles in general get their name from a peculiar behavior made possible by their body structure. Elaterids have a spine on the underside of the thorax that snaps into a groove on their “chest.” The beetles are so smooth, frequently covered in soft hairs of slick scales, that predators have a hard time grabbing the insects without the slippery, torpedo-shaped beetles escaping. However, should a bird or other animal manage to get a grip, the beetle snaps that spine into the groove with such force as to eject it from the predator’s grasp, or startle the attacker into dropping it.

Alaus lusciosus from Mission, Texas

It was formerly assumed that the clicking mechanism was used by the beetle to right itself should it land on its back….and indeed, the beetles do this as well. Smaller click beetles can vault themselves up to ten inches into the air in attempts to land on their feet. Oddly, the big eyed elaters can barely pop up an inch or two.

Keep an eye out for eyed elaters in your own region, especially during late spring and in June and July. At least some adults may overwinter in cavities in rotten wood, where they may be encountered at any time of year.

Sources: Arnett, Ross H., Jr., Michael C. Thomas, Paul E. Skelley, and J. Howard Frank (editors). 2002. American Beetles Vol. 2. Boca Raton, FL: CRC Press. 861 pp.
Bartlett, Troy, et al. 2012. “Genus Alaus,” Bugguide.net
Evans, Arthur V. 2014. Beetles of Eastern North America. Princeton, NJ: Princeton University Press. 560 pp.