Insects keep the soundtrack of late summer alive

I really enjoy these late summer evenings and nights – not for the warmth, but for the sounds that fill the night air. I’m not sure if you’ve noticed, but the sounds outside at night can’t be heard at any other time of year.

The spring and early summer months have a pleasant hum from the few insects that are calling, but it doesn’t come close to the soothing chorus of late summer.

The sounds of late summer kind of creep up on us without our noticing. Each evening, a few more insect species join the orchestra of night sounds.

To understand why the evenings are so loud, you need to understand the life cycle of many insects. In the northern states, most insects spend the winter as eggs. With the warmth of spring, those eggs begin to hatch.

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Most insects go through several life stages before becoming reproductive adults. For example, it may take two weeks for the eggs to hatch into the larval form. That worm-like stage can take another four weeks or longer.

Then they go into the metamorphosis stage, where the insect rests for a week or two before emerging as the adult form. It is the adult form that is able to reproduce.

This often involves the males singing or calling for females, and it takes most of the summer to get to this stage of life. What you hear outside at night are the adults calling to attract mates so they can lay eggs that will survive until next spring. And it takes the entire spring and summer to reach this point.

One of these nighttime songsters is the conehead katydid. They are a group of large, green insects that look and sound similar. They are easily recognized by their cone-shaped heads, extremely long antennae and long, angular legs. The cone-shaped head gives them a distinctive look. No one knows why the head is shaped this way or what function it serves. But as soon as you see one, you notice the cone-shaped head.

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Most of these katydids are two to three inches long, making them among the larger insects. They are bright green, which helps them blend into their environment, though some species are brown.

As you might imagine, a large, juicy insect like this makes a good meal for many other critters. In fact, conehead katydids are a favorite target for parasitic wasps. The adult wasp captures and stings the katydid to paralyze it, then flies back to its underground chambers, leaving the helpless insect as a fresh meal for its eggs when they hatch.

Coneheads have large, powerful jaws, which they use to eat both insects and fruit and seeds. They are fastidious cleaners, often using their mouths to clean their feet. Their antennae are extremely long, sometimes even longer than their bodies. Females have a long, straw-like appendage extending from their abdomen. This structure, called the ovipositor, is used to deposit eggs into plant tissue or the ground.

They are found in weedy fields, native prairies, wetlands and along forest edges. They are also common in both rural and suburban areas.

It is the male that is the songster. In fact, this is how they got their name – from the sound produced by rubbing their wings together. They rub the sharp edge of one wing over the file-like ridge of the other to create a sound like “katy-did, katy-did, katy-didn’t.”

Combine hundreds of these calls with a myriad of other insects, and you have the wonderful sounds of the late summer nights.

Until next time …

Editor’s note: Stan Tekiela’s NatureSmart column appears twice a month in the Eden Prairie Local News. Tekiela is an author, naturalist and wildlife photographer who travels extensively across the United States to study and capture wildlife images. 

You can follow his work on Instagram and Facebook. He can be contacted via his website at www.naturesmart.com.