HOUSE FLIES, CENTIPEDES, AND OTHER INSECTS. 57 



With the approach of cold weather the nests are abandoned, most 

 of the individuals, including all the workers and males, perishing, and 

 only the perfect females, the product of the last fall brood, wintering 

 over. Early in spring these over-wintered females come out of the 

 cracks in logs or holes in walls, etc., in which they have hibernated, and 

 unaided originate new colonies of workers, which by midsummer often 

 contain 20,000 or more individuals. No honey, wax, or pollen is stored 

 in the nests, but the young are fed by the workers on a liquid derived 

 from insects or other substances eaten. 



The paper wasps have a number of natural enemies. They are cap- 

 tured and devoured by two species of robber flies, and in addition tbeir 

 underground nests, as I am informed by woodmen, are frequently dug 

 out by foxes and skunks, which feed on the larvae and pupae contained 

 in them. 



The best means of abating the wasp nuisance is to discover the nest 

 and destroy the inmates. Ordinarily by watching individual wasps the 

 nest can be located, and the introduction of a few spoonfuls of chloro- 

 form or bisulphide of carbon into the entrance, after all have come in for 

 the night, will suffice to destroy the inhabitants. 



Other Yespas, especially the common bald-faced hornet ( Vespamacu- 

 lata Linn.), which builds large paper nests in trees, also enter houses, 

 but not so abundantly as the small yellow and black species referred to. 

 The slender yellowish-brown wasps (Polistes spp.), which build uncovered 

 combs attached to rafters and in trees, are also frequent visitors in 

 houses, but are not so pugnacious and will rarely attack anyone unless 

 they are accidentally taken hold of or their nests disturbed. All of these 

 wasps are of more or less service to housekeepers in that they are 

 active enemies of the common house flv. 



C. L. M. 



