138 NEW YORK STATE MLSEUM 



to our knowledt^e of these interesting forms. His paper gives a very 

 good idea of the inter-relations existing between the various species. His 

 studies show that there are 21 primary parasites of this pest and three 

 others that probably hold the same relationship. He obtained 14 hyper- 

 parasites and I I species were reared from tlead chrysalids or cocoon masses. 

 He states that in Washington 1). C, Pimpla i n q u i s i t o r Say and 

 Chalcis ovata Say | tig. 18, 1 9 | are the two species most effective in con- 

 trolling this pest, and that large numbers of the former insect hibernate as 

 larvae within the cocoons of the host, while in no instance was the latter 

 parasite reared from cocoons of Hemerocampa taken the previous winter. 

 He has also shown that when hymenopterous parasites are comparatively 

 scarce, certain tachinids may destroy large numbers of this pest, the more 

 important being Tachina mella Walk., Frontina frenchii \\"ill. 

 and Euphorocera claripennis Macq. Besides those mentioned 

 above, Dr Howard gives the following as primary parasites of this species : 

 Pimpla c o n q u i s i t o r Sa)-, P i m j) 1 a a n n u 1 i ]> e s Say, A m o r p h o t a 



r g y i a e How., M e t e o r u s c o ni m u n i s Cres., M e t e o r u s h y p h a n- 

 triae Riley, Limneria sp., Limneria valida Cres., Theronia 

 fulvescens Brulle, A pan teles deli cat us ffow., A pan teles 

 hyphanlriae Rile)-, Apan teles parorgyiae Ashm., P t e r o- 

 mains c u p r o i d e u s 1 low., C r a t o t e c h u s o r g y i a e F"itch, T e 1 e- 

 nomus orgyiae Fitch, P" r o n t i n a aletiae Riley, E x o r i s t a 

 griseomicans V. d. W. and W i n t h e m i a 4 - p u s t u 1 a t a F"abr. At 

 Washington these parasites became so abundant that in the autumn of 1895 

 about gOyr of the larvae were destroyed. In addition to the above named 

 parasites, Dr Howard records that Ichneumon s u 1j c y a n e u s Cres., 



1 c h n e u m on c o e r u 1 e u s Cres. and A 1 1 o c o t a t h y r i d o p t e r i g i s 

 Rile\- were all observed investigating recently formed 1 Icnu-rocampa cocoons 

 and were a|)])arcnlly about to ovi])osit. The last, he states, is parasitic 

 upon Pimpla. 



In his study of these parasites I)r Howard found tliat llie conditions 

 were not uniff)rm In all parts of the city of Washington, the parasitism being 



