APANTELES MELANOSCELUS GIPSY-MOTH PARASITE. 11 



generation maggot about two hours to form its cocoon and the sum- 

 mer maggot three to four hours to complete the cocoon in which it 

 is to hibernate. 



The cocoon made by the spring-generation maggot is pale yellow- 

 ish white, a little smaller and rather delicate as compared with the 

 hibernating cocoon, which is a light sulphur yellow and very tough. 



LOCATION OF COCOONS. 



The cocoons of the spring generation are found singly or in 

 clusters, depending upon the degree of gipsy moth infestation and 

 the abundance of Apanteles. In low growth the cocoons are very apt 

 to be found on the foliage and often on the debris on the ground, 

 as well as along the trunk and small branches. On large trees a few 

 cocoons are found on the foliage, but if abundant the majority are 

 located at the junction of the smaller branches on the underside. 

 The cocoons are attached lightly, often on top of others and in- 

 variably a dead second-stage gipsy moth larva is found with each 

 cocoon (PL II, B, C, D). After the adults have issued these cocoons 

 are easily washed or blown from the trees and are seldom found the 

 next spring. 



The second-generation cocoons are found securely attached scat- 

 teringly over the tree trunk and in clusters under the larger limbs 

 where the gips3^'-moth larvae congregate. These cocoons are not 

 often found on the foliage. 



The gipsy-moth larvae, when parasitized by the second generation 

 of Apanteles melcmoscelus^ have a tendency to crawl to protected 

 and out-of-the-way places just before the issuance of the parasite 

 maggots. The cocoons are often associated with the gipsy-moth, 

 pupae and larger caterpillars. They are found behind billboards 

 and signs, attached to trees (PL III, D), on the undersides of 

 boards on the ground (PL II, A), under fence rails or rocks, under 

 loose bark, and on rough surfaces on the underside of limbs (PL 

 III, B, C). Plate III, A, shows a tin vessel found during the sum- 

 mer of 1920 in a dump at Weymouth, Mass., and illustrates the 

 habit of parasitized larvae of crawling to hidden places. There are 

 a few over 100 cocoons on the bottom of this vessel, and there is a 

 cluster of 25 cocoons on one side of the vessel not shown in the 

 photograph. 



SEASONAL mSTORY. 



The seasonal history varies considerably with the season. The is- 

 suance of adults of Apanteles melanoscelus from their hibernating 

 cocoons begins about the time of maximum hatch of the gipsy-moth 

 eggs, which is usually near the middle of the second week in May. 

 During such a season most of the Apanteles will have issued by May 

 20. Under field conditions females of Apanteles melanoscelus do not 



