Nature Bulletin No. 467-A   OPctober 21, 1972
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:HORNETS, WASPS AND YELLOW JACKETS

Wasps and bees and ants make up a group which occupies top place on 
the family tree of the insect world: partly because of their complicated 
anatomy but mostly because of the built-in-automatic features of their 
behavior which many people mistake for intelligence. Their elaborate 
ways of housing and feeding their young, or the division of labor among 
members of their colonies, do not signify intelligence. They merely 
inherit these instinctive traits.

The wasps include a multitude of kinds ranging in size from parasitic 
species almost invisible to the naked eye and reaching their full growth 
inside the tiny eggs of other insects, up to the giant Cicada-killers. Most 
kinds are so small or so scarce that they are seldom seen or recognized 
by ordinary people, but there are four types familiar to most of us in the 
middle west.

The Mud Daubers or "solitary wasps", the White-faced or "Bald-headed 
Hornets, the Yellow Jackets, and the Paper Wasps, rear their young in 
cells which are as precisely engineered as those in a honeybee comb but 
are made of mud or paper instead of wax. The last three are called 
"social wasps " because of their caste systems and the division of labor 
within their nests. Unlike bees, they feed their young on animal matter 
instead of nectar and pollen from flowers. We avoid wasps because a 
female defends her nest with a painful stinger and, unlike a honey bee, 
she can sting many times.

The common blue-black Mud Dauber typifies our expression "wasp-
waisted" because its abdomen is a mere knob at the end of a long 
slender stem. As a female gathers mud and then trowels it into place at 
the chosen nest, she seems nervous, fidgety, and constantly jerks her 
iridescent wings. One by one, the tube-like mud cells are completed, 
stuffed with captured spiders, and egg placed in each, and then sealed. 
Each spider is paralyzed by a sting precisely placed so that it will 
remain inert but alive until the wasp's grub hatches out and needs it. 
When fully grown, the plump whitish grub weaves a silken cocoon 
inside the tube and changes into a pupa. Some emerge as adults that 
season; others in spring.

The other three familiar types, social wasps, are the world's finest 
papermakers. They chew up bits of weathered wood, waste paper and 
cardboard to build many-celled combs of tough membranes. The queen 
of the colony lays an egg in each cell. When it hatches, the grub is 
constantly tended and fed on chewed-up insects -- first by the queen; 
later by infertile female workers.

Hornets build an egg-shaped nest, often a foot in diameter, anchored on 
a branch of a tree or shrub, with many tiers of combs enclosed in sheets 
of gray flaky paper, and an entrance at the bottom. A Yellow Jacket's 
nest is similar but smaller and located in an old mouse nest 
underground, in a stump, or in a brushpile. Most commonly seen are the 
exposed unbrella-like combs of the Paper Wasp suspended, by short 
stems, under the eaves of houses or inside barns, sheds, and other 
sheltered places.

Among these social wasps, as with the bumblebee, only fertile queens 
survive the winter, and not in the old nest but hidden away in the walls 
of buildings, hollow trees, crevices under the bark of trees, or among 
trash. In spring she starts a new nest with a few cells which produce 
workers. Gradually, they take over and the queen is free for her main 
job of laying eggs. Later, certain grub are fed special diets so that some 
will develop into young queens. Males or drones come from 
unfertilized eggs.