144 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



Anomalon exile Pro v. 



Quite commonly reared as a parasite of the tent caterpillar and not 

 infrequently as a parasite of the brown-tail moth, apparently attack- 

 ing the caterpillars before pupation and probably while they are still 

 very young. Its frequency as a parasite of the brown-tail is well 

 indicated in Table VI (p. 147), which records the results of the 

 summer's rearing work of 1910. 



Theronia fulvescens Cress. 



This is probably, as in the case of the gipsy moth, the most common 

 native hymenopterous parasite. No attempt has been made to deter- 

 mine whether it is commonly primary or secondary in this connection, 

 but it is presumably primary in the majority of instances. 



PlMPLA CONQUISITOR SAY. 



The pupae of the brown-tail moth seem to afford much more suitable 

 conditions for the development of the Pimpla larvae than do the pupae 

 of the gipsy moth. In consequence this Pimpla is frequently reared 

 and is probably about as important as a parasite of the brown-tail 

 moth in America as are the European species, Pimpla examinator 

 and Pimpla instigator, abroad. 



Pimpla pedalis Cress. 



This species is never so common as Pimpla conquisitor in its asso- 

 ciation with the brown-tail moth. It is apparently identical in habit 

 with the more common species, but if results in studies in parasitism 

 of other hosts are to be excepted, it is more apt to occur in forests and 

 woodland than in open country. 



Diglochis omnivora Walk. 



At times Diglochis is a common parasite of the brown-tail moth 

 pupae, but in 1910 it was unexpectedly scarce in Massachusetts, 

 although it seemed to have been much more common in Maine, judg- 

 ing from the small amount of material which has been received from 

 tl^at State. 



Syntomosphyrum esurus Riley. 



Of irregular occurrence as a parasite of the brown-tail moth, but 

 among the more effective of the native species in 1910. It was first 

 reared in 1906 by Mr. II . L. Webster, while associated with the lab- 

 oratory, and not again encountered until 1910, when large numbers 

 issued from material collected in certain localities, as will be seen in 

 Table VI which shortly follows. 





