AGRICULTURAL EXPERIMENT STATION. 139 



spring, 1891 and previously, we have bred a Chalcid fly from the 

 eggs of this species. Thus the efforts of fungi, larval and egg 

 parasites combined aid in holding them in check. The parasites 

 have increased rapidly the past season and there will be compara- 

 tively few caterpillars in 1891. The parasites bred were Pimpla 

 conguisitor, (Say), Anomolon near exile, Prov., Tachina clisio- 

 catnpa, Townsend and Phorocera promiscua, Townsend. 



The Tachinas were new to entomologists aud were named and 

 described by Prof. C. H. Tyler Townsend in Psyche for May, 

 1891. The Phorocera was very abundant. Eighty of the one 

 hundred and thirty-five cocoons collected at random were infested 

 by it. This spring we bred from the eggs of this species as stated 

 above, a minute four-winged fly which we sent to Prof. C. V. 

 Riley for identification and received the following reply, which we 

 record for the benefit of entomologists, it being too technical for 

 the comprehension of those not versed in entomology. "The 

 specimen is a species of Tetrastichus, a genus in which we have an 

 indefinite number of undescribed species in this country, which are 

 very difficult to separate. Your species is probably undescribed. 

 Tetrastichus is invariably, so far as we know, hyper-parasitic and 

 the primary parasite, is, in your case, probably, a Telenomus or a 

 Trichogramma." 



