APANTELES MELANOSCELUS GIPSY-MOTH PAEASITE. 13 



recorded as a host of this parasite in Europe, was not found in 

 America until the latter part of June, 1920, when a heavy infestation 

 was discovered at Medford, Mass. When the infestation was found 

 the larvse were from half to full grown and rather too large to be 

 expected to harbor A. melcmioscelios maggots. Collections of larvae 

 were made immediately, but no A. melanosceliis were reared. On 

 several occasions, however, cocoons of this species were found on tree 

 trunks closely associated with belated larvse of Stilj^notia salicis, and 

 there is very little doubt that these cocoons were spun by A. mela- 

 noscelus maggots which had issued from the near-by small and 

 inactive larvse of S. salicis. It is known that with the gipsy moth 

 the larvse from which A. melanoscelus maggots issue do not die for 

 several days. They are rather inactive and often do not move far 

 from the place where they were when the parasite issued. 



In August, 1920, an outbreak of Hemerocampa leucostigma S. & A. 

 was located in a small area in Somerville, Mass. This is the first 

 time since -4. melanoscelus has been established that larvse of the 

 white-marked tussock moth could be collected in eastern Massachu- 

 setts, except very sparingly. The season was too far advanced to 

 expect to rear A. melanoscelus from collected material, and none were 

 recovered from larvse brought to the laboratory. It was apparent, 

 however, from observations made at the infestation, that this parasite 

 had been responsible for the untimely death of very many tussock- 

 moth larvse, for the cocoons of A. melanoscelus were abundant, on 

 the sheathing of near-by houses Avhere the tussock-moth larvse had 

 gathered in large numbers and were spinning their cocoons. 



Several experiments vrere tried confining adults of ^1. melanoscelus 

 with various larvse. Reproduction was successful with M alacosoma 

 americana Fab., M. disstria Hlibn., Hemerocaofri'pa leucostigma S.& 

 A., Olene ho^iflava Pack., and Euprocfis Ghrysoo'-Thoeal^. The female 

 attacked all but the last eagerly. Oviposition apparently took 

 place in Charidryas nycteis D. & H., Hemileuca m,aia Dru., Pteronus 

 rihesii Scop., and in a species of tortricid. All of these larvse died 

 and were dissected. Several maggots of A, melanoscelus were found 

 in the larvse of C nycteis, but no evidence of parasitism was found in 

 the other larvse. 



Several larvse of S'tilpnotia salicis were presented to females of 

 A. melanoscelus. No oviiDosition v*'as recorded. This was late in the 

 season and the larvse had matured much beyond an attractive stage 

 for oviposition by this parasite. 



Some six or seven species of smooth-skinned or hairless larvse have 



been confined with females of A. melanoscelus but rarely have they 



shown any attention to them. This parasite evidently will attack 



quite a number of small hairy lepidopterous larvse when the oppor- 



73070°— 22 3 



