Insect Relationships (or Their Absence)

Story and photos by Claire Stuart

Valentine’s Day is celebrated this month, so you might wonder what, if any, relationships are found in the insect world. Insect lives are short — mostly just a year or two — and most of that time is spent as larvae. The larval stage is for eating and growing, and larvae have no functioning reproductive system.

The adult stage is for reproduction and is very short — sometimes only a day or two, or even just a few hours — so there is little time for malefemale relationships. Adults do not grow and some adults don’t even eat. Females usually live longer than males because they have to lay eggs and, in some cases, provide food and care. Males seldom stay around after the mating act, but there are notable exceptions.

Only adult insects have wings (and a winged insect of any size is an adult) because wings are usually needed to find mates and egg-laying sites. The first thing adult insects need to do is to find each other, and there are many ways they do it.

The easiest way for potential mates to meet is to form a swarm. This is common in many types of tiny flies. They gather in large numbers over some landmark like a bush or fence (or even a person) so that they can be seen at a distance.

Female moths and butterflies and some other insects emit attractive airborne chemicals (pheromones). Males can sense it on the wind from miles away using sensors on their antennae, and follow it to the females.

Airborne sound and vibrations are other ways that insects get together. We are all familiar with the chirps of crickets. The male calls and the female follows the sound to the male. Some male crickets call from the opening of a burrow or other place that amplifies the sound. I found a tiny cricket in my kitchen making a big sound as he chirped from the opening of a glass jar on the counter! Bush and tree crickets, katydids, and cicadas gather in male groups called choruses to call in unison; females fly into the chorus. Some insects such as stoneflies and plant hoppers communicate by vibrations, striking a body part against whatever object they are sitting on.

Of course, we see fireflies lighting up summer nights. Each species has a unique flash pattern. The females stay in one spot and flash, while males fly around searching for them.

When a male spots a female of his species, he answers her, they have a dialog, and he lands to mate. Unfortunately, some females can mimic the flashes of other species and when a male of another species lands, she eats him!

Male dragonflies live several months and establish territories along ponds and slow water. Their larvae are aquatic and may live a few years. Adult males constantly patrol their territory and mate with any females that enter. After mating, the male grips the female and carries her over the water, dipping her abdomen into the water to lay her eggs, preventing any other male from mating with her.

A few male insects do stay around and play a role. Carpenter bees, familiar spring visitors, nest in holes in wood. Although only females can sting, the male stays with the nest until it is completed and eggs are laid. He is a great faker and flies in the faces of any large perceived enemies, including people, who get near the nest. He head-butts rival males and potential parasites or predators.

The common pipe-organ mud-dauber wasp male also defends the home while the female is out gathering building material and provisions for the larvae. Like all other male bees and wasps, he is stingless, but when he flies in your face you are wise to retreat because he could just as easily be a female, who can sting.

Dung beetle adults (rollers) work together to provision their burrow nests. The male finds some manure, rolls it into a ball and presents it to a female. Together they roll it to a site suitable for digging, then tunnel under it to sink it into the ground. They mate, the female lays eggs, and the male departs. Male earwigs also help the females construct their nests, but depart before eggs are laid.

The large black beetles known as Bessbugs live in family groups in rotten logs. Males and females live several years, and live with and care for their larvae. The next generation of adults also stays for a while a nd helps.

The best insect father is the burying beetle that feeds on small dead animals, finding them by odor from over a mile away. When a male or female finds a body, it emits a pheromone to attract a mate. They meet and immediately dig a chamber to sink and cover it before actually mating. The female lays eggs, and both parents chew up the body and feed larvae. If something happens to the female, the male continues to care for the larvae until they pupate.

Send your insect questions to me at: buglady@wv.net.