December, '09] journal of economic entomology 459 



any obstacle for the purpose of oviposition. There is reason to 

 suspect, therefore, that Dr. Smith unwittingly supplied a compara- 

 tively few females which were actually reared from his material with 

 conditions peculiarly suitable for their rapid reproduction, with the 

 extraordinary results which he chronicles. 



Bathythrix pimplae, originally described by Dr. Howard from a 

 few specimens reared by him from cocoon masses of the tussock moth, 

 and considered to be a parasite of Pimpla inquisitor, was reared in 

 rather small numbers in the aggregate from the cocoons of Spilo- 

 eryptus. Usually only one or two cocoons in each mass were attacked, 

 and two or three of the secondary usually came from each individual 

 host cocoon. Like Dibrachys, Bathythrix responds almost immedi- 

 ately to forcing, and the females are able to oviposit for two genera- 

 tions in the sluggish larvae of the Spilocryptus. It is very probable 

 that there is at least one full generation in the spring, and possibly 

 two or more. 



Hemifeles periliti Ashm. was occasionally encountered as a parasite 

 of Spilocryptus, and in one very remarkable instance, of Ophion. No 

 living specimens were secured, and since it was difficult positively to 

 distinguish its cocoon exuviae, etc., from those of Bathythrix, its 

 identity could only be established through the occasional dead adults 

 found. The occurrence of a dead adult within the cocoon of Ophion 

 established this record indisputably, and it is indeed remarkable that 

 a species which can successfully mature within the cocoon of a minute 

 Apanteles can also attack a host at least one hundred times larger 

 than itself. 



An undetermined species of Pimpla was reared in very small num- 

 bers from the old cocoon masses of Spilocryptus, within which it had 

 apparently passed a considerable portion of the previous summer. It 

 was thought possible that the record was based on error, and that the 

 actual host was some other insect which had sought the shelter 

 afforded, but later another individual was reared from a cocoon of 

 Ophion, and its identity as a secondary parasite associated with 

 promethea was definitely established. 



Another secondary parasite, not yet determined, but belonging to 

 the exceedingly remarkable genus Perilampus, was reared from the 

 puparia of Achaetoneura, from the cocoons of cecropia. 



Spilochalcis, which was reared by Dr. Smith in some numbers ap- 

 pears to be a rather uncommon insect in southeastern New England, 

 and no surprise was felt in not encountering it at all in this work. 



