AN INTERESTING HABIT OF A WAX MOTH PARASITE.* 



By S. A. Graham, 



Assistant in Division of Economic Zoology, Minnesota State Experiment Station. 



INTRODUCTION. 



During the fall of 1916, while rearing the bee moth, Galleria 

 mellonella m the insectary for experimental purposes, a Pteromalid 

 parasite Dibrachys clisiocampcB Fitch f was observed to be 

 very common about the breeding cages. Further investigation 

 disclosed the fact that these parasites were emerging from the 

 cocoons of the bee moth. They were so abundant that very 

 few of the larvae of the host were able to pupate and come to 

 maturity. This is interesting inasmuch as previous records of 

 the parasitej give the host as the forest tent caterpillar, 

 Malacosoma dis stria. 



During March these same parasites were emerging in such 

 numbers from nucleus hives stored in the laboratory of the Bee 

 Division that the windows of the room were literally covered 

 with the small black insects. 



_ Insofar as can be ascertained from the literature at hand, 

 this parasite has never been recorded as attacking the bee moth,' 

 nor has its complete life history been described. This being the 

 case and considering the possible value of this parasite in 

 checking the ravages of the bee moth in stored combs, it was 

 deemed advisable to keep the insect under observation during 

 the winter and to determine as fully as possible its life history 

 and habits. 



LIFE HISTORY. 



The host is attacked after spinning the cocoon, usually 

 while still m the larval stage, but occasionally the pupa while 

 still soft and white, may be attacked. The female parasites 

 walk rapidly over the cocoons feeling the surface with their 

 antenna. When a suitable place is found the caudal end of the 



. * ^"i^.^i^^^J.with the approval of the Director as Paper-No. 82, of the Toumal 

 Series of the Minnesota Agricultural Experiment Station Journal 



M .•' 1 A^^ identification, I am indebted to Mr. A. T. Girault formerlv of the 

 National Museum, Washington, D. C v^irauit, lormeriy ot the 



New^YoJk^agl 43T'^ °" ^°'''°"'' ^""^^^^^^ ^"^ °ther Insects of the State of 



175 



