234 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



in contact with insects dead of the wilt. The active Sarcophagid 

 flies, after leaving such material, were captiu'ed with a clean net 

 and introduced into small, clean vials. Other, less active specimens 

 were secured in glass vials after they had left a smear of wilt. The 

 specimens were killed by placing the vials, plugged with clean cotton, 

 in a cyanide jar. The Calosoma sycophanta larvae taken, were removed 

 from a mass of gipsy moth larva? and pupae which was moist with the 

 fluid oozing from their dead bodies. Great care was used in collecting 

 the specimens, so that they were secured bearing no more wilt con- 

 tamination on their bodies than they would naturally carry when 

 free and unmolested. 



Polyhedra were found on a majority of the specimens captured. 

 Feet and mouthparts especially were examined and both found to 

 harbor polyhedra. 



In collecting specimens, insect scavengers were most frequently 

 found in contact with larv£e and pupse dead of the wilt, and of these, 

 certain Sarcophagidse were by far the most abundant. Adult Sar- 

 cophagids were repeatedly observed walking over, feeding or depositing 

 maggots on diseased material. They were often abundant in the tree- 

 tops and on warm, bright days were very active, flying rapidly from 

 leaf to leaf. They appeared early in May, and were abundant until 

 the end of the pupal stage of the gipsy moth which terminates the 

 epidemic of wilt. A number of Sarcophagid adults, found walking 

 over or feeding on diseased material, were taken, and nearly all were 

 found to be carrjang polyhedra on their feet or mouthparts, or on both. 

 Their abundance, the fact that they frequent wilt, that they are car- 

 riers of polyhedra, and are repeatedly found on the foliage upon which 

 gipsy moth larvse feed, all strongly suggests that the Sarcophagidse 

 do work of considerable importance in distributing the disease. 



Other insects were occasionally observed in contact with the disease. 

 Adult Elaterids were twice found feeding on gipsy larvae that had 

 died of the wilt, and on both occasions were found to carry polyhedra. 

 Polyhedra were also found on two adult Coccinellidae that were taken 

 under similar circumstances. An unknown Hemipteron, and an 

 unknown beetle larva taken wading through a fresh smear of wilt, 

 and three Calosoma sydophanta larvae captured in association with 

 wilt material were all found to carry polyhedra. Polyhedra were 

 also found to be carried by minute red mites. Ants were often ob- 

 served on trees bearing the bodies of many larvae and pupae dead of 

 the wilt. They occasionally fed on this material, but more commonly 

 seemed to avoid it. The ants were collected several times and poly- 

 hedra were found once on an insect that had been captured crossing 

 a dried smear of wilt. 



