PARASITES OF GIPSY-MOTH PUP.E. 239 



is probably similar to that taken by P. conquisitor or P. pedalis in 

 America. On this account it is not considered as probable that 

 either P. examinator or P. instigator will ever become established in 

 America as a result of the not very satisfactory colonies which have 

 been liberated. They will, of necessity, enter into direct conflict 

 with the American species for a share in the business of being para- 

 sites upon a certain section of the insect community, including a 

 large number of species of which the gipsy moth is but one. Compe- 

 tition may result in cut rates and more and cheaper parasitism for a 

 time, but eventually, if the newcomers ever secure a foothold at all, 

 they will either drive the natives out of the business or else share 

 and share alike with them in accordance with an amicable and 

 natural agreement. 



In consequence, no assistance is expected from the various foreign 

 species of the genus Pimpla as parasites of the gipsy moth or of the 

 brown-tail moth. They are merely liberated when received, under 

 the best conditions which can be afforded looking for their estab- 

 lishment, and if they are ever recovered from the field, the most that 

 is expected of them is that the circumstances surrounding such 

 recovery will exemplify the truth of the above remarks. 



ICHNEUMON DISPARIS PODA. 



One of the most distinctive of the gipsy-moth parasites, and one 

 of the first, if not the very first, described as attacking that host, 

 Ichneumon disparis is at the same time one of the less common, if 

 dependence is to be placed upon the rearing records at the labo- 

 ratory. It may be that it is never common, or it may be that it is 

 eastern and southern in its distribution in Europe, rather than 

 central and western; some few incidents in connection with its impor- 

 tation have indicated that perhaps its scarcity in European imported 

 material was due to such material having been collected outside of its 

 natural range. In any event not more than two score of individuals 

 have been reared in the course of the five years since the work was 

 begun. 



Very little is known of its life and habits, other than that it probably 

 attacks the pupse or perhaps the prepupse, and never the active 

 caterpillars. It is thought possible that it hibernates as an adult, 

 and if this is true, it might conceivably be a parasite of importance 

 could enough be secured to make possible a sufficiently strong colony. 

 To date there never has been a single mated pair available for libera- 

 tion at any one time. 



