"Doodlebugs" (Antlions)

Growing up in Oregon, all I knew initially of antlions was what I read in books. The insects are members of the family Myrmeleontidae in the order Neuroptera. So, they are related to lacewings, mantispids, spongillaflies, and their kin. I wasn't even sure antlions could be found in the Pacific Northwest, but I was fascinated by the "pits" that the larvae supposedly dug to trap ants and other insects.

Adult antlion, Colorado

The images in books never gave a sense of scale, so I imagined that the funnel-like holes must approach the size of a saucer. Ha! Most antlion pits are about the diameter of a quarter, as shown in the image below.

"Standard size" Myrmeleon pits on gentle slope, Colorado

Sometimes they are larger, but the size of the crater does not correspond to the size of the larva that digs it. The breadth and depth has more to do with soil texture, and whether there is a slope or not.

Larger Myrmeleon pits on steeper slope, Colorado

Antlion larvae might be considered among the ugliest and/or most terrifying of insects, and indeed they must be to their victims. Most are about the size of a large pea, but they are wrinkly, studded with spines, and with spindly legs. Their most remarkable feature is a pair of long, hooked mandibles.

Antlion larva, Kansas

Ironically, these mini-monsters are best known by the cute moniker of "doodlebugs." They can create random, cursive "doodles" in sand in the process of finding a new place to dig a pit, and that may be the source of the colloquial name.

Actually, it is only larvae of the genus Myrmeleon that make the trademark pits here in North America. Pretty much all the other genera simply bury themselves just below the surface of the soil and wait with jaws agape for a hapless insect to pass by.

Antlion larva, Colorado

Myrmeleon larvae can only walk backwards, but they do so rapidly. They dig a pit by walking in reverse, and in a spiral, throwing sand with their jaws and the flattened top of their head. They then lie in wait beneath the soil at the very bottom of the pit. The sloping sides of the funnel are highly unstable and any small insect that reaches the lip of the trap begins descending immediately. The larva senses the vibrations and throws additional sand onto the victim to hasten its doom.

The jaws of a doodlebug are hollow, and the larva injects a cocktail of enzymes that paralyzes its victim and begins extra-oral digestion of its tissues. The doodlebug then reverses flow, imbibing the liquified innards of its prey. The resulting dry carcass is then catapulted out of the pit with a violent thrust of the antlion's head.

Scotoleon nigrilabris female, Colorado

Doodlebugs more than make up for the horrid appearance of their youth by metamorphosing into delicate, slender, lacy-winged adults that superficially resemble damselflies. These fairy-like insects fly clumsily, and are most often seen among tall grasses, especially at dusk.

Myrmeleon immaculatus, Massachusetts

Note the short, thick, clubbed antennae that instantly distinguish them from damselflies. Males frequently have a much longer abdomen, tipped with bracket-like claspers. This is especially true of the genus Scotoleon.

Adult male Scotoleon, Arizona

Despite the fact that adult antlions are fairly large, they are ridiculously cryptic. I have personally witnessed flying antlions alight on grass stems or twigs, and instantly align themselves so perfectly as to be essentially invisible. Dark spots and speckles on the wings break up their outline, but they also flatten themselves seamlessly against the substrate.

Myrmeleon exitialis, Colorado

There are eighteen (18) genera of antlions recorded north of Mexico, with 94 species. Some are truly spectacular, like the three species in the genus Glenurus that sport black, white, and pink wingtips.

Glenurus luniger, Arizona

The genus Vella includes three species, which are true giants. Adults have a wingspan of 100-120 millimeters or more. They are found in about the southern third of the U.S., and are frequently attracted to lights at night.

Vella americana, Texas

Look for the larval pits of Myrmeleon in fine, powdery soil, or sawdust around rotten logs. Where there is one there are usually several. Prime situations for such colonies are at the base of trees, beneath rock overhangs, under bridges, the dirt floor of old barns and sheds, and any other situation that remains perpetually dry. They can be in exposed situations, but I find that is rarely the case.

Myrmeleon pits under a rock overhang, Arizona

Watch for adult antlions at your porch light at night.

You can tickle doodlebugs at the bottom of their pit with a grassblade or twig, and get them to throw sand or grab the offending object. You can also keep them in captivity by providing a fairly deep container of fine sand and periodically dropping in ants and other invertebrates. They can take down surprisingly large prey.

Adult antlion, Ohio

Antlions pupate inside a silken capsule the larva spins underground, incorporating grains of sand into the cocoon.

Enjoy looking for, and observing, these amazing insects, then share your story here, on Facebook, or elsewhere, like The Antlion Pit (though I am not certain this is still an active website).

Brachynemurus abdominalis, Massachusetts

Wasp Mantisfly

Maybe I am simply excitable in general, but I was ecstatic to find a truly astonishing insect species earlier this week here in Colorado Springs. I spied what I thought was an ordinary paper wasp (Polistes sp.) on the underside of a sunflower blossom, but something wasn't quite right. Short, quivering antennae finally betrayed it as the Wasp Mantisfly, Climaciella brunnea. These bizarre insects are most closely related to antlions and lacewings in the order Neuroptera.

As I wrote in the Kaufman Field Guide to Insects of North America, mantispids "resemble a science experiment gone horribly wrong. Imagine shrinking a praying mantis, then attaching its front end to the hind end of a lacewing, and you have a mantispid."

In the case of C. brunnea, the body form has been further modified to look like a paper wasp. The resemblance is uncanny. The base of the abdomen is constricted into a "wasp waist," and the wings are rotated such that they fold over the back instead of pitched roof-like as in other mantispids. Even more amazing, the leading half of each wing is darkened, to resemble the longitudinal fold in the wings of vespid wasps. When startled, the Wasp Mantispid even splays its wings like an agitated paper wasp.

Wasp Mantisfly in defensive pose

An actual paper wasp, Mischocyttarus flavitarsis

As if the adult insect is not strange enough, the life cycle is simply mind-boggling. The adult female C. brunnea deposits clutches of literally hundreds, even thousands of eggs, each on a short filament, usually on the underside of leaves. The tiny larvae that emerge probably drop to the ground. They then adopt a posture whereby they are standing more or less upright, on their hind end, swaying, and legs waving in the air. They aim to glom onto passing spiders. Only one larva per spider will survive, and competition must be keen. Assuming only one larva boards a given spider in our example, the story progresses this way: The larva clings to the margin of the spider's carapace (top part of the cephalothorax), waiting for the spider to reproduce. Should the spider be a male, the larva must transfer to a female during mating. The mantispid larva must then wait until the female begins constructing an egg sac.

Before the female spider finishes closing her egg sac, the mantispid larva must enter the sac. The larva cannot penetrate an egg sac that is completely enclosed in silk. Once inside, the larva begins feeding on the spider eggs.

At least three wolf spider hosts have been recorded for C. brunnea: the Rabid Wolf Spider, Rabidosa rabida, and two unidentified members of the genus Schizocosa (Redborg and Redborg, 2000) in Illinois. The entire life cycle from egg to adult requires at least one year.

Look for the adult mantispids on flowers, especially sunflowers, thistles, and milkweed, where they wait to ambush other insects. I found a total of five specimens in quick succession on sunflowers at the edge of a big vacant field of shortgrass prairie on August 13, 2014, and three more on August 15 in the same location. So, they can be very localized in abundance.

Apparently the males live but a very short time, less than a week. Females persist for about a month. Emergence times vary, between May and October, but the overwhelming majority seem to be seen in June, July, and August.

This species is widely distributed, and while considered scarce is probably more common than we realize. It is recorded from southern Canada and nearly every state except the Pacific coast states, Idaho, and Nevada, then south through most of Central America.

Sources: Boyden, Thomas C. 1983. "Mimicry, Predation, and Potential Pollination by the Mantispid Climaciella brunnea var. instabilis (Say) (Neuroptera: Mantispidae)," J. NY Entomol. Soc. 91(4): 508-511.
LaSalle, Mark W. 1986. "Note on the Mantispid Climaciella brunnea (Neuroptera: Mantispidae) in a Coastal Marsh Habitat," Entomol. News 97: 7-10.
Leckie, Seabrooke. 2010. "Mantisfly," The Marvelous in Nature.
Redborg, Kurt E. and Ellis G. Macleod. 1983. "Climaciella brunnea (Neuroptera: Mantispidae): a mantispid that obligately boards spiders," J. Nat. Hist. 17(1): 63-73.
Redborg, Kurt E. and Annemarie H. 2000. "Resource Partitioning of Spider Hosts (Arachnida, Araneae) by Two Mantispid Species (Neuroptera, Mantispidae) in an Illinois Woodland," J. Arachnol. 28(1): 70-78.

Beast Into Beauty: Aphidlions

Perhaps no insects embody “beauty and the beast” better than the green lacewings of the family Chrysopidae. The average person would be hard-pressed to make the connection between the hideous larva and the delicate adult it is destined to become. Who could blame them? Gardeners might easily mistake the sickle-jawed immature stage as a villain rather than a hero.

The family name Chrysopidae translates to “gold eye,” and indeed the adults of some species of green lacewings have eyes that seem to have fallen out of a kaleidoscope. The family belongs to the insect order Neuroptera or “nerve-winged insects.” This name comes from the dendritic pattern of wing venation and is not to imply that the wings of these insects feel any kind of sensation, at least any more so than in any other insect.

There are fourteen genera and at least 85 species of green lacewings occurring in North America. No doubt more species await description by scientists. These are very abundant animals, and just about everyone, from city center to rural countryside, has had an adult green lacewing or two (or several) visit their porch light at night. What can easily escape attention, however, are the other stages in the life cycle of chrysopids.

Let’s start with the egg stage. Believe it or not, the little white balls on the ends of these hairlike stalks are lacewing eggs. One could mistake the egg clusters for the fruiting bodies of some kind of fungus, and when they appear on a leaf or stem, cause a gardener some degree of concern. The female lays her eggs on these stalks for good reason: to keep them out of reach of predators like….well, her offspring’s siblings for example. So voracious are larval lacewings that they will not hesitate to cannibalize a brother or sister right off the bat.

Larval lacewings are undeniably ugly: worm-like bodies studded in clusters of spines, with a head dominated by jaws that look like ice block tongs. As if they are aware of their own ugliness, the larvae of some species conceal themselves under a layer of debris that they stick on those clusters of spines along their backs. What goes into this “garbage pile” might include bits of lichen, dust, or even the bodies of their victims. The real reason the larvae disguise themselves is not to redeem their ugly appearance, of course, but to make them appear innocuous to their prey and hide them from their own predators.

Lacewing larvae prey mostly on aphids, which has earned them the nickname “aphidlions.” They won’t pass up the opportunity to kill a caterpillar or other insect, either. They simply approach a prey insect and grab it with their jaws. Puncturing the body of their prey, they inject fast-acting paralytic compounds and digestive enzymes that go to work immediately on the victim, essentially liquefying its internal organs and tissues. The aphidlion then draws out a fluid meal, also through its hollow jaws.

Aphidlions are themselves vulnerable to various predators, namely the ants that guard colonies of aphids. Aphids secrete a sweet, liquid waste product called honeydew, and this is highly coveted by ants. The ants therefore vigorously defend the aphids from their predators and parasites. So, those lacewing larvae hidden under a blanket of debris might more easily escape detection by ants than a naked aphidlion would.

Once it emerges from the egg, an aphidlion proceeds through only three instars (intervals between molts). A mature larva will then spin an opaque, silken cocoon before transforming into the pupal stage. The mature adult will chew its way out of the cocoon, leaving the empty vessel looking like a tin can with the lid hanging by a hinge of remaining metal.

The adult insect is delicate-looking but durable, and highly colorful. They find mates by a kind of Morse Code, drumming their abdomens in a species-specific rhythmic pattern that the opposite gender recognizes. So precise is this courtship “song” that some species can be separated only by differences in their tune. The species themselves are physically identical. The adults do feed. Some continue their predaceous lifestyle, but others feed on aphid honeydew, or nectar or pollen.

Green lacewings are best appreciated as living creatures. The color of their bodies and eyes quickly fades after death. Be on the lookout for the larvae, but be careful. There have been reports of bites from larvae that fall out of trees and onto people, with reactions to bites varying from a nuisance to extremely painful with relatively persistent effects. Mostly, lacewing larvae should be considered among your best friends when it comes to waging war on garden and crop pests.