Flying Ants

I recently came across a male specimen of the "legionary ant" Neivamyrmex nigriscens while walking our dog in our Colorado Springs neighborhood. It was instantly recognizable to me, but it got me thinking about how most people would be hard-pressed to know what it was. Unfortunately, there are very few references for the identification of winged ants. This is a shame because it is often the "alates," males and winged queens, that are most obvious to the public.

Male Legionary Ant, Neivamyrmex nigrescens, Colorado

Indeed, worker legionary ants are mostly subterranean and nocturnal in their habits (nomadic, raid the nests of other ants to prey on the larvae and pupae), so hardly ever observed by the average person. Meanwhile, a homeowner may not notice he or she has an ant "problem" until the colony swarms, liberating a cloud of alates.

Alate queen carpenter ant, Camponotus sp., Colorado

Alates are typically larger than the worker caste of wingless, sterile females, so are more noticeable for that reason as well. In many cases, the winged reproductives resemble the workers in general appearance, but this is not always the case. The thorax of winged ants is frequently greatly expanded to accommodate the muscles that operate the wings, giving males in particular a distinctive "hump-backed" appearance.

Male carpenter ant, Camponotus sp., Massachusetts

Swarms are usually seasonal, and triggered by changes in day length, relative humidity, and air pressure, especially in the arid southwest U.S. where the onset of the monsoon rainy season sparks many ant species to swarm. These emergences can be spectacular events. Worker ants open new exits from nests in the soil, and scour the immediate vicinity to rout any potential predators and parasites.

Red Imported Fire Ant swarm, Solenopsis invicta, Georgia

Many swarm events take place in late afternoon, at dusk, after dark, or at dawn. Winged ants may be attracted to outdoor lights, which can lead to the assumption that the ants came from the house or building when that is not necessarily the case.

Colonies of a given species in a localized area swarm simultaneously such that members of different colonies can find each other and increase genetic diversity while decreasing the potential for inbreeding. Winds, and the insect's own muscle power, can take the ants far from their colony of origin.

Rough Harvester Ant swarm, Pogonomyrmex rugosus, Colorado

How do you know whether it is a winged ant or a winged termite? Please read my post on termite swarms for a concise explanation, and images of winged termites. Below is an image of a winged termite to compare to the ants illustrated here.

Alate dampwood termite, Zootermopsis laticeps, Arizona

What about wasp versus ant? That is a more problematic distinction, but most ants have distinctly "elbowed" antennae, whereas wasps often do not; or at least the first segment of the antenna is not as long as it is in ants. There are exceptions, of course, like the male Neivamyrmex ant shown at the top of this post that has no obvious elbow in the antennae.

Male Pavement Ant, Tetramorium sp., Colorado

Fortunately, I am not the only one who recognizes the need to pay more attention to alate ants in terms of research and public awareness. Laurel Hansen and Art Antonelli include a key to alates in their publication, listed below. Brendon Boudinot, in a guest post for Alex Wild's Myrmecos blog, extols the virtues of studying male ants for a clearer understanding of the phylogeny of the family Formicidae.

Alate queen thatching ant, Formica sp., Colorado

Sources: Boudinot, Brendon. 2013. "Male Ants Demystified," Myrmecos.Hansen, Laurel, and Art Antonelli. 2011. Identification and Habits of Key Ant Pests in the Pacific Northwest. A Pacific Northwest Extension Publication 624. Pullman, WA: Washington State University. 14 pp.
Houseman, Richard M. 2008. "Ants." University of Missouri Extension.

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.