October, '10] 



FISKE AND BURGESS: HETEROCAMPA 



391 



injury from the serious defoliation sustained the previous year. 

 Examinations of the fallen leaves were made in order to determine the 

 percentage of Heterocampa larvae that had been destroyed the previous 

 season, as well as to find out the average number of moths that emerged 

 sucessfully. Mr. Collins continued the work and visited several 

 localities near North Conway, Intervale, and Tam worth where the 

 caterpillars had been abundant during the previous year, making 

 counts of the pupae found in badly infested areas and in sections 

 nearby. The following table gives the summary of the counts made 

 by him in the different locahties and shows the number of pupae 

 destroyed by different natural enemies, as well as the number of moths 

 which emerged in a normal manner. Twenty-seven out of 28 eggs 

 examined by Mr. Collins were found to have been destroyed by 

 Telenomus. 



WORK OF HETEROCAMPA ENEMIES. 



Locality. 



Moths T 

 emerged. 



White Horse Cliff 

 Mount Kearsarge 

 Mount Hurricane 

 Mount Surprise 

 Tamworth, N. H. 

 Tamvrorth, N. H. 



2 

 6 

 5 

 17 

 1 

 3 



34 



By computing the totals in this table it will be found that 87 per 

 cent, of the Heterocampa pupae in the region were destroyed by the 

 larvae oi frigidum during August, 1909, which is slightly higher than 

 the figures secured last summer, and 3.66 per cent, died from the 

 attack of parasites or from other causes. The small percentage of 

 moths — 9.33 — which emerged during the spring would undoubtedly 

 have caused some injury to the foliage had it not been for the interven- 

 tion of the tiny egg parasite already mentioned, although it is fair to 

 assume that the caterpillars would have been seriously decimated by 

 the swarm of frigidum beetles which must have developed from the 

 large number of larvae of the previous year. If we assume that the 

 sexes of the moths were evenly divided, it is apparent that on the 

 average only one female was developed from 21 pupae of the previous 

 year. This enormous reduction which was caused by the work of 

 Calosoma is, of course, of great importance, still it must be remembered 

 that each Heterocampa female is capable of depositing 500 or more 

 eggs according to observations made by Miss Patch on this insect in 

 Maine. It, therefore, is clear that the primary factor in bringing 

 Heterocampa under natural control, aside from the work of Calosoma 

 frigidum was due to the little egg parasite. 



