185 



parasite since determined as Euhiomyia calosomae, Coq. Townsend's 

 description of this fly is quoted and an account is given of each instar. 

 It has been bred from G. sycophanta in many parts of eastern Massa- 

 chusetts and in parts of Maine, New Hampshire and Rhode Island, 

 It is probably native to New England, having been first bred from 

 C. calidum, which it has infested to the extent of 4*4 per cent, for 

 a period of years, the figure for C. sycophanta being only 3'4 per cent, 

 or less during 1915-1918. 



The eggs of E. calosomae are laid on the exterior surface of the 

 adults of Calosoma (the larvae not being attacked) singly, or hi 

 groups of 2, 3 or 4. The period of oviposition during three years' 

 observations was from 19th July to 16th August. Several experiments 

 in longevity gave an average of 18 days. E. calosomae hibernates in 

 the second larval instar within the body cavity of the beetles. The 

 young larva upon hatching enters the body, probably through the 

 spiracles, and reaches the second instar about the time that the 

 beetles enter the earth for hibernation. In spring the parasitised 

 beetles, weakened by the presence of the parasite, begin to work 

 their way upward through the ground in search of food. They die 

 after two or three days on, or near, the ground surface, and the parasites, 

 emerge shortly before the normal field emergence of C. sycophanta^ 

 There are two full generations of E. calosomae in a year and a partial 

 third under favourable conditions. The egg-stage lasts from 3 to 24 

 hours, the larval stage from 9 to 12 days, pupation from 9 to 18 days. 

 If beetles infested by flies of the summer generation immediately 

 become inactive and dormant, the parasite apparently does hkewise ,' 

 but if the host continues to feed actively, the parasite reaches the; 

 adult stage and gives rise to a partial second summer generation. 



This parasite has been bred from C. sycophanta, C. frigidum and 

 C. calidum collected in the field in New England, and from one 

 individual of Carabus nemoirdis , and it is probable that other beetles 

 belonging to these genera are attacked. The only instance of second- 

 ary parasitism has been the discovery of one puparium of E. calosomae 

 containing a larva of Chalcis sp. There is an abundance of E. calo- 

 somae issuing in late July and August, after the beetles have begun 

 to enter the ground for hibernation, and many must perish unless 

 they attack some other host than Calosoma or Carabus. This mav 

 account for the present limits to the increase of the parasite. Should 

 C. calidum become very abundant in eastern Massachusetts and 

 New Hampshire, where C. sycojjhanta is already numerous, the 

 abundance of the parasite may also increase materiaUy, and constitute 

 a serious handicap to the usefulness of C. sycophanta in New England. 



Wade (0.). The Four-Spotted Cowpea Weevil (Bruchus quadri- 

 maculatus, Fabricius). — Oklahoma Agric. Expt. Sta., Stillwater, 

 Bull. 129, November 1919, 14 pp., 6 figs. [Received 2nd March 

 1920.] 



Bruchus quadrimaculatus, F., its life-history, natural enemies, and 

 methods of control are described. About seven generations of the 

 insect take place in. a year, and though depredations start in the 

 field, the greatest damage is done to the stored seed. 



(673) B 



