Feb. 2. I920 Life History of Eubiomyia calosomae 491 



elytra, dorsum and lateral portions of prothorax, ventral portion of 

 abdomen, and femora of Calosoma sycophanta. 



During the season of 191 6, summer generation flies in cages deposited 

 95 ^ggs on 38 beetles, and in 1917, they deposited 177 eggs on 68 beetles, 

 or an average of more than 2 per beetle for each season. Of those de- 

 posited in 1 91 7, 61 eggs were found on the abdomens, 52 on the protho- 

 races, 20 on the metathoraces, and scattering ones on the legs and elytra 

 of the various beetles. The largest numbers deposited on one beetle in 

 the breeding experiments were 10 and 9 during 191 6 and 1917, respec- 

 tively. 



The period of oviposition in the cage experiments was from July 28 to 

 August 16 in 1916, from July 22 to August 12 in 1917, and from July 19 to 

 July 27 in 1918. 



The flies in the breeding cages are most active during the late afternoon 

 and early morning — the times at which adults of Calosoma are least 

 active. Oviposition was obser\^ed in a cage on August 6, 191 5, at 5.50 a.m. 

 and at 6.35 a. m. The flies were observed to run after the beetles as early 

 as 4 a. m. — the breaking of day. Eggs have also been found deposited 

 on beetles between 5 p. m. and dusk. The female fly lights near the bee- 

 tle and mounts upon the dorsum of its host either by crawling upon it 

 or by a short flight. The beetles in cages sometimes show little disturb- 

 ance from the presence of the parasites near or upon them. Occasionally 

 they are seen to run slowly away from the active flies. 



COPULATION 



Attempts were made to observe copulation of this species at various 

 periods during the season in 191 5 and 191 6. Pairs of flies were inclosed in 

 lamp chimneys and glass jars and provided with foliage and a sugar 

 solution. Observations were made frequently, the flies being separated 

 at night and returned to the receptacle each day, but negative results 

 attended these efforts until 1917. 



On July 21, 1917, one male and three female flies issued in a vial. 

 The male, which was less than 24 hours old, was transferred to a vial con- 

 taining another female of the same age. Copulation ensued within two 

 minutes, continuing for a period of six minutes, whereupon the pair was 

 transferred to the large breeding cage with other specimens. After this 

 period many fertile eggs were secured during the progress of the experi- 

 ment. 



LONGEVITY 



On July ID, 1 91 5, two males and two females, newly issued specimens, 

 were inclosed in a wooden tray with glass cover to obtain data on the lon- 

 gevity of the species. Foliage and cotton saturated with sugar solution 

 were also supplied in the tray. The length of life was as follows : One 



