Feb. 2, 1920 Life History of Eubiomyia calosomae 495 



parasite apparently do likewise. But, on the contrary, if the beetles 

 continue active and feed for a period of 10 days to 2 weeks after becoming 

 parasitized, the larv^ae continue to develop until they reach the adult 

 stage, there being thus a partial second summer generation. 



HOSTS 



Parasites have been bred from adults of Calosoma sycophanta, C. 

 frigidum, and C. calidum collected in the field in New England. Large 

 numbers were bred from the first species because of its great abundance 

 and fewer from the other two species because of their rarity in comparison 

 with C. sycophanta. Eggs have also been deposited on C. wilcoxi in the 

 breeding cage and the parasite reared to the second or hibernating larval 

 instar. The host which died in hibernation contained two larvse. 



One specimen of Carahus nemoralis, collected by P. S. Coffin, Fram- 

 ingham, Mass., May 18, 1916, was dissected and found to contain a large 

 puparium of Eubiomyia calosomae. On July 26, 191 8, two eggs were 

 deposited by the parasites in a breeding experiment upon a specimen of 

 C. nemxyralis. This parasitized host later entered the earth for 

 hibernation. 



It is very probable that this parasite attacks some species of Calosoma 

 and Carabus occurring in New England, other than the ones here recorded, 

 but the remaining species of these genera are comparatively rare. It 

 is also possible that Eubiomyia calosomae may be responsible in a meas- 

 ure for the scarcity of some of the remaining species of the genera. 



I^arvae of Calosomxi sycophanta, C. frigidum, and C. scrutator were 

 exposed to the flies in the breeding experiments but without results. 

 The flies paid no attention to the larvae and made no attempt to oviposit 

 upon them. A collection of i ,546 large larvae of C. sycophanta was made 

 during the summer of 191 5 and reared to maturity to determine whether 

 Eubiomyia calosomae attacks the larvae, but no parasites were reared. 

 Doryphora decemlineata, Lachnosterna sp., Porthetria dispar, Euvanessa 

 antiopa, Hyphantria cunea, and Estigmene acraea larvae were also exposed 

 in the breeding cages but without action on the part of the flies. 



NATURAL ENEMIES 



On November 6, 191 5, one dead adult of Calosoma sycophanta, collected 

 in Randolph, Mass., contained one puparium of Eubiomyia calosomae 

 Coq. On December 14, the puparium was dissected and found to con- 

 tain a large lar\'a of Chalcis sp. as determined by Mr. C. F. W. Muesebeck, 

 formerly of this bureau. Other puparia have been dissected with no 

 further indications of secondary parasitism. 



ECONOMIC STATUS OF THE PARASITE 



This parasite has two complete generations and a partial third per 

 year, adults issuing in May and June and again in July and August. 

 After a few days the flies which issue early have an abundance of hosts 



