Forest Preserve District of Cook County (Illinois)
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!
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