Nature Bulletin No. 78   August 10, 1946
Forest Preserve District of Cook County
Clayton F. Smith, President
Roberts Mann, Superintendent of Conservation

****:KATYDIDS

These August nights you will hear the katydids: "Katy did. She did. She 
didn't." There are two notes more often than three. Though harsh and 
monotonous it is a melancholy sound because it means that summer will 
soon be over. They sing only in late summer and early fall. The farmer, 
whose life and livelihood are governed by the weather, shakes his head 
and reckons the first frost will come six weeks after the katydids begin 
to sing. The males make the call, although in a few species the female 
can give a feeble chirp. It' s strictly a male debating society.

The katydids, like their close relatives: the grass hoppers and crickets, 
have two pairs of wings. The fore pair -- upper when folded back -- are 
larger and stiffer than the soft membranous rear or under pair. The song 
is made by scraping a toothed file-like edge on the base of the left fore 
wing across a hard knife-like edge on the right fore wing. Grasshoppers 
sing by rubbing their hind legs against their wings, whereas crickets rub 
the upper and lower pairs of wings together.

There are many species of katydids but only a few are common in this 
region. Some live in trees; some in meadows. Some are brown, some 
spotted, some green, depending upon the species and the vegetation 
upon which they live. Some sing at dusk and dawn; some sing all night. 
Some lay their eggs in crevices on the soft bark of a tree; some lay them 
on a leaf; some split the edge of a leaf and lay their eggs between the 
two layers. Held in captivity, these have been known to split the edge of 
a piece of writing paper to lay their eggs.

Our common broad-winged katydid is a large green hump-backed 
slabsided fellow that lives in trees and is rarely seen. They have a very 
long delicate antennae, long hind legs, and are good jumpers but their 
night is usually short.

The adults all die in the fall. The eggs lie dormant through the winter 
and hatch in late spring directly into a miniature katydid which grows, 
molts its skin, and repeats the process until mature. There is no larva or 
pupa stage.

If you will notice carefully, they sing faster on hot nights. On cold 
nights they are silent except perhaps for a few hoarse chirps.

"Katy did. She didn't" Make up your mind!