the bald-faced hornet's nest

This summer I spotted a large paper nest in the maple tree in our front yard. When it came time to write a short final paper for field biology, I chose it as my subject.

The bald-faced hornet (Also called Dolichovespula maculata in Dunn (255) is not a true hornet, but in the wasp (Vespidae) family, related to the yellow jacket, but with a larger body and black and white coloration. Its face is white, suggesting the name. They are social wasps, who form communities built on a caste system, consisting of a queen who is served by her sterile female daughters. With mouthparts for biting and chewing, vegetarian adults drink liquids and feed on ripe fruit; they masticate insects to feed the carnivorous larvae.
In the spring, a fertile queen builds a small nest alone, lays an egg in each cell, feeds the larvae, and a first generation of “daughters” is born. The queen keeps their ovaries from developing by aggressive behavior towards them in the “form of head butting and shoulder charging” (O’Toole 190) and they become workers who enlarge the nest, creating cells for the queen’s eggs. All she does from the time the worker generation emerge is lay eggs; the workers bring her food, defend the nest, collect wood pulp to enlarge the nest with many additional cells, and gather food and feed the larvae. The legless, grublike larvae signal for food by scratching on the walls of their cells and a worker will offer a tiny pellet of masticated insects, often mosquitoes or flies. There are reports of worker wasps snatching a fly in mid-flight. Farmers welcome the bald-faced hornets who live near cattle or horse barns.
When the adult insect emerges, she too becomes a worker. She seals off her cell, which has collected excrement, and it is enlarged it to make room for a new egg. The colonies grow all during the summer and may contain as many as 500 or more individuals. These become very aggressive if disturbed and each individual can and will sting repeatedly.
The nest has one entrance hole towards the bottom and is well insulated with several outer layers of paper to maintain an ideal temperature of about 86 degrees F (30C) If it becomes too warm, the workers will cluster around it and beat their wings to cool it down and bring in drops of water to moisten the cells; if too cool, the workers will perform an exercise, rapidly expanding and contracting their abdomens, and raise the temperature (Frisch 62).
Both the initial small nest and the subsequent large one are made of paper in the same way. The insects use their serrated mandibles to scrape weathered wood, often posts, fences, and telephone poles, for pulp; mix the pellets with their saliva and build the nest by stretching out each section, aligning the wood fibers for strength (Frisch 61). As they build, they use their antennae as calipers to measure the walls of each cell. A glandular secretion is added to outer surface; it hardens like lacquer to waterproof the paper (Wooten 126).
The elaborate nests are used for only one season; at the end of summer a generation of fertile females and males emerges and mates. The males die. The fertile queens overwinter in leaf litter or in the hollow of a tree; the workers become disoriented and die. The queens start construction of a new nest each spring.
 This seems like an extraordinary labor-intensive and elaborate system for insuring the continuance of the species. 

References
Dunn, Gary A. , Insects of the Great Lakes Region, Ann Arbor, University of Michigan Press, 1996.
Frisch, Karl von, Animal Architecture, New York and London, Harcourt Brace Jovanovich, 1974.
Milne, Lorus and Margery, The Audubon Society Field Guide to North American Insects and Spiders, New York, Alfred Knopf, 1980.
O’Toole, Christopher, Alien Empire: An Exploration of the Lives of Insects, New York, Harper Collins, 1995.
Stokes, Donald W., A Guide to Nature in Winter, Boston, Little Brown and Co., 1976.
Wooten, Anthony, Insects of the World, London, Facts on File, Cassell Illustrated, 2002.