52 



second group are the two predaceous bugs, Podisus placidus Uhler 

 and Podisus seriventris Uhler, which Kirkland"^ has recorded feed- 

 ing upon the caterpillars. Saunders records^' a species of Trom- 

 bidium feeding upon the eggs. 



Parasitic insects. — The parasitic insect enemies may also be 

 divided into two groups : The dipterous parasites and the hymenop- 

 terous parasites. Of the former group Coquillett'* records the 

 following as parasites of the caterpillars ; Euphoracera claripennis 

 Macq., bred by C. H. Fernald, Amherst, Mass., Frontinia frenchii 

 Will., previously recorded by Harvey'' and Tachina mella Walk, 

 also previously recorded by Harvey. During the past season 

 the writer has also bred the last named species together with 

 Calliphora erythrocephala Meigen, which Coquillett states is 

 evidently a scavenger. Both species were kindly identified by 

 Mr. D. W. Coquillett. 



The second group, the hymenopterous parasites, are probably 

 more effectual in keeping the forest tent-caterpillar and other 

 insects in check, because they are usually much more abundant. 

 The following species have been recorded as preying upon the 

 caterpillars. Limneriafugitiva Say, recorded'" by Riley, and /Vw/i/a 

 pedalis Cres"., by Wm. Saunders.^' From the 2,500 cocoons kept 

 by the writer in the laboratory 287 individuals of the species 

 Pimpla conquisitor ^er& reared, of which 218 were females, leaving 

 69 males ; Pimpla pedalis, two females and one male ; Theronia 

 fulvescens, one male. The following species kindly identified by 

 Mr. Wm. H. Ashmead, assistant curator of the U. S. National 

 Museum, were also reared from these cocoons : Diglochis 

 (^Phromalus') omnivorous Walk. ; Miotiopis clisiocampcs Ashm. 

 As shown on page 48 but 312 or only about 12}^ per ct. of the 

 2,-500 cocoons were parasitized. 



Disease. — A disease, evidently bacterial, attacked many of the 

 caterpillars last season materially reducing their numbers. This 



'^ Mass. (Hatch) Agr. Exp. Sta. Bull. 46, p. 25. 



»?Ann. Rept. Ent. Soc. Ont. 1878, p. 28-30. 



='Bull. No. 7, U. S. Dep. Agr. Div. Ent. Tech Series, pp. ir, 16, 21, 24. 



"'Psyche, May 1891, p. 85. 



'"Insect Life, 8: 157. 



3'Insects iDJurious to Fruits, p. 57. 



