54 



The Gypsy Moth. 



brown, wrinkled, pointed, and three-quarters of an inch long. 

 Pupation lasts about fourteen days. The moth lays eggs in 

 clusters containing from 400 to 500, which are covered with 

 the yellowish hairs of her body, upon trees and in every 

 other conceivable place. 



Experiments in changing egg clusters rapidly from a high 

 to a low temperature were conducted, with the following 

 results. In March, 1895, four egg clusters were changed in 

 twenty minutes from a temperature of 8o : above zero to 5' 

 above zero, and left all night in a freezing mixture of calcium 

 chloride and snow. Two hatched on April 9th, and two on 

 April nth. On March 20th, 1895, tw0 e g"§" clusters were 

 exposed to a temperature of 80"' F. They were then packed 

 in a mixture of chloride of calcium and snow, reduced in 

 fifteen minutes to a temperature of 20 : below zero, a fall of 

 100'". They were kept in this temperature for thirty minutes.. 

 By April 16th all had hatched. 



Fortunately there are numerous parasites and predaceous 

 insects which in some circumstances materially check the 

 increase of the Gypsy moth. Among these are hymenop- 

 terous insects, especially some species which place their eggs- 

 well within the tissues of the skin of the larvae and pupae- 

 From these eggs maggots are hatched which feed on, and 

 destroy, their hosts. Certain dipterous insects also destroy 

 larvae and pupa? in this manner. There are also several 

 species of beetles which devour the caterpillars, notably two 

 species of Calosoma. Species of Ht7?iiptera-Heteroptera — plant 

 bugs — notably Podisiis serieventris y are also useful, in 

 destroying the caterpillars, and cages were contrived for 

 breeding and protecting these, as well as the beetles alluded 

 to above. 



Birds also are eminently useful in destroying the Gypsy 

 moth in one or more of its forms. Thirty-eight species of 

 birds have been identified in Massachusetts as feeding upon 

 it, although it is believed somewhat generally that birds 

 will not eat hairy caterpillars. 



It appears that there are birds in Massachusetts which eat 

 the eggs of insects extensively, like the titmice in Europe, 

 and it is suggested that the habits of European insect-egg- 



