OF WASHINGTON. 139 



tions have been determined are hyperparasites. Syntomosphy- 

 rum esurum Riley has never been proved to be either secondary 

 or primary. It is, or was, a common parasite of Aletia argil- 

 lacea in the cotton fields of the South late in the summer. It 

 issued frequently and in great numbers from old chrysalids left 

 hanging bare upon the cotton stalks. The chrysalids on being 

 opened were found full of this parasite, and no trace of a prim- 

 ary'parasite was ever found. Hence this insect was considered 

 in Bulletin 3 of the U. S. Entomological Commission, and in the 

 Report on Cotton Insects by J. H. Comstock, published by the 

 Department of Agriculture in 1879, to be a primary parasite. 

 The question as to whether it might not be a secondary parasite was 

 raised by me in the 4th Report of the U. S. Entomological Com 

 mission. It was reared, as recorded in Bulletin 5 (Technical 

 Series), of this Division, by Dr. A. D. Hopkins, at Morgan- 

 town, W. Va., from, Orgyia leucostigma. It was reared abun 

 dantly in 1896, in the late winter and early spring, at Washing 

 ton, D. C., from the chrysalids of Hyphantria cunea. Moreover 

 it was reared by F. M. Webster in 1889 on May 3rd, according 

 to the notes of the Division, from the galls of Trypeta gibbet 

 Loew, on Ambrosia artemi sice folia. But these Trypeta galls, 

 especially late in the season, are apt to contain several different 

 kinds of insects, not only primary parasites but frequently lepi- 

 dopterous, coleopterous and dipterous larvae, so that the rearing 

 from the gall means nothing at all, the presumption, however, 

 being that the insect came from the Trypeta either as a primary 

 or a secondary parasite. 



Summing this evidence all up, we have the insect reared 

 undoubtedly from lepidopterous chrysalids and from coleop 

 terous chrysalids (that is to say, the Coccinellids under consider 

 ation) and also possibly from dipterous insects. Unity of habit, 

 that is to say, unity of host relation, is so marked among the 

 Chalcididae that wherever such a diversity in the apparent hosts 

 occurs it has become my rule to place such parasites as undoubt 

 edly secondary or tertiary parasites. The primary parasites of a 

 given group of insects belong to certain definite groups. Exam 

 ples are so numerous that they need not be mentioned. In no case 

 in the whole family, to my knowledge, are the parasites of a 

 single genus parasitic on more than one order of hosts, and in 

 some instances they are confined even to individual families of 

 hosts, and the assumption that a single species of Chalcidid may 

 be reared from coleopterous, from lepidopterous, as well as pos 

 sibly from dipterous hosts, is almost an absurdity. These are 

 the principal reasons upon which I base my belief that Syntomos- 

 phyrum esurum is a hyperparasite." L. O. H. 



