212 SEVENTEENTH Report STATE ENTOMOLOGIST OF MINNESOTA—1918 
fiber, gathered from old fences, sheds, etc., chewed up and cemented 
by glandular secretion. A colony consists of males, females and 
workers, the latter being imperfect females. These carry on all the 
industrial work of the colony while the perfect females are egg lay- 
ing. The nests are only used for a single season, the cold weather of 
fall killing off all but the young females. Even in the tropics, the 
colonies die off annually. While Vespula arborea and V. sylvester and 
V’. norwegica, as well as others, suspend their nests from trees, bushes 
and elsewhere, ’. germanica and V. vulgaris form nests below the sur- 
face of the ground. 
Females that have hibernated, start their cells in early part of 
summer; “the solitary female wasp begins by making three saucer- 
shaped receptacles in each of which she deposits an egg; she then pro- 
ceeds to form other similar shaped receptacles, until the first eggs 
deposited are hatched and the young grubs require a share of her at- 
tention. From the circular bases, she now begins to raise her hexagonal 
cells, not building them up at once, but from time to time, raising them 
as the young grubs grow.” Proc. Ent. Soc. London 1858 p. 52. 
Next to Polistes, Vespula (Vespa) is the most abundant genus. 
Members of both of these genera feed their young upon the chewed 
up fragments of Lepidoptera and other insects. Adult yellow-jackets 
feed on meat, fresh or decaying, on insects, dead fish, exposed 
fruit, raw or preserved, and on all sweet material. Vespula (Dolicho- 
vespula) maculata, the bald-faced hornet, is perhaps the best builder 
of globe nests; V. germanica and V. cuneata (“yellow jackets”) 
usually build in hollows in stumps or in stone fences or underground. 
Sometimes, however, their nests are found suspended from bush, tree 
or building. One may see in the spring, the single comb nest made 
by the queen of Vespula, suspended from bush or elsewhere, partially 
enclosed in paper covering. 
Both Polistes and Vespula are subject to parasites; the former is 
sometimes parasitized by Xenus a beetle belonging to the Stylopidae. 
Vespula is attacked by Stylopids, and by at least two species of Ichneu- 
mons. 
Underground wasp nests, which may become very large, can be 
destroyed by pouring into the nest at dusk, a little bisulphide of carbon. 
The large paper nests of hornets may be rendered untenable by drench- 
ing them with kerosene. It is safer to do this after dark if possible. 
