8 BULLETIN 417, U. S. DEPARTMENT OF AGRICULTURE. 



All outbreak of Heterocampa guttivitta in the White Mountam dis- 

 trict of New Hampshire and parts of Maine began to attract atten- 

 tion in 1906 and 1907. The moths increased rapidly for several 

 years and large areas of hardwood growth on the mountain sides 

 were completely stripped. In 1909 this destruction reached its 

 climax. Calosoma frigidum had by this year increased to such 

 proportions that its effective work was everywhere evident in local- 

 ities where these caterpiQars had made their appearance. The 

 junior writer had an opportunity of visiting several localities in 

 North Conway, Intervale, and Tamworth, N. H., on August 20, 

 1910, when conditions were almost entirely relieved in so far as the 

 ravages of the caterpillars upon the foliage were concerned. Ex- 

 aminations were made of many small areas of leaf mold where the 

 moths had pupated in August, 1909, and it was found that an average 

 of 87 per cent of the pupae had been destroyed by the larvae of 0. 

 frigidum, and that 3.7 per cent had died from the attack of parasites 

 or from other causes. The remaining 9.3 per cent emerged during 

 the spring of 1910, and the females deposited eggs that were imme- 

 diately attacked by a small egg parasite, Telenomus gra-ptse. How., 

 which destroyed practically all of them. This shows the good work 

 of Q. frigidum coupled with the timely aid of parasites.^ 



A similar example of effective control to that of C. frigidum on 

 Heterocampa guttivitta in New Hampshire was noted by Dr. J. B. 

 Smith ^ in southern New Jersey a few years ago. This had to do 

 with an outbreak of a geometrid caterpillar which covered the scrub 

 oaks in enormous numbers. Calosoma scrutator and C. wilcoxi Lee. 

 were also there in enormous numbers on the young oaks, feeding 

 upon the geometrid caterpillars. Dr. Smith visited the locality the 

 year following the outbreak but could not find a single specimen of 

 beetles or caterpillars. This is an instance in which the beetles 

 came in and made an entire clean-up of the lepidopterous pest, after 

 which they evidently migrated to other sections and in aU proba- 

 biUty many died of starvation. 



Oalosoma calidum is quite common in localities where cutworms 

 are doing great damage to crops. It is sometimes difficult to find 

 adults of this species or their larvae actually preying upon the worms, 

 but the evidence of their presence in such an environment usually 

 bespeaks their mission. Besides, as stated before, it is believed that 

 0. calidum is more or less nocturnal in its food habits, which is much 

 in its favor as an efficient enemy of cutworms. Numerous other 

 accounts are on record concerning the beneficial work of the various 

 species of Calosoma, although the previous records of some of the 

 species are rather fragmentary. 



LIMITS ON INCREASE OF SPECIES OF CALOSOMA. 



Probably the most potent factor to be reckoned with when con- 

 sidering the increase of any species of Calosoma is the possible food 

 supply. Second to this is the feeding and pupation habits of its 

 lepidopterous host, for it is necessary that the caterpillars be feeding 

 and pupating at the time when the adult beetles will reproduce. 



> The notes with others were published by Messrs. Burgess and Fiske in the Journal of Economic Ento- 

 mology, Volume 3, Number 5, page 389, 1910. 

 i Smith, J. B. [Note.] In Ann. Ent. Soc. Amer., v. 4, p. 179, 1911. 



