Nature Bulletin No. 82 September 7, 1946
Forest Preserve District of Cook County
Clayton F. Smith, President
Roberts Mann, Supt. of conservation
Gardeners have remarked this summer upon the unusual number of
lady-bugs. This was largely due to the great quantity of aphids or plant-
lice last year. Like all other animals, insects have enemies which
normally tend to limit their numbers if man does not upset things. These
enemies may be diseases, mites, reptiles, rodents, birds or other insects.
As an insect becomes abundant its enemies, too, tend to become more
numerous. These soon deplete their food supply and themselves decline
in numbers, after which their prey increases again. And so it goes, in
There are large numbers of insects of different kinds which prey on
other insects. Cone group consists of parasites that live within or on a
single "host" and gradually consume it. The other group surprises the
predators which, as adults or larvae or both, kill and eat large numbers
of their prey. Among the most beneficial of the predator insects are the
"lady-bugs" or ladybird beetles: known to children because of the Old
Mother Goose rhyme; praised and protected by the vegetable gardener,
the farmer, the fruit grower and the forester.
The adults of the many species that feed, both as larvae and as adults,
on aphids are nearly hemispherical in shape, about 1/4 inch or less in
diameter, with reddish or yellowish wing-covers decorated with black
spots, or black wing-covers with white, red or yellow spots. The
number, size, location and color of the spots distinguish the species.
They hibernate during the winter in protected places, emerging in
spring to lay their eggs. The larvae are active strange-looking creatures,
many of them mottled with bright colors and covered with warts or
spines, always fiercely hungry.
The two plant-eating exceptions, the bean lady-bug and the squash lady-
bug are destructive pests. Those that feed on scale-insects are smaller,
flatter an shiny black some of them having red or orange spots. These
were introduced from Australia as a means of combating the San Jose
and other scales. Most of our native species prey on the aphids that
infect melons, cucumbers, squash, pumpkins, corn fruit trees or forest
The male lady-bug is called just that.
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Update: June 2012