64 CALOSOMA SYCOPHANTA. 



Experiments in Crossbreeding Calosoma sycophanta and C. scrutator. 



During the summer of 1910, Mr. Collins conducted several experi- 

 ments to determine whether these two species would interbreed. 

 The beetles are of nearly the same size and it seemed worth while 

 to determine whether this would occur in the field. 



June 20, 1910, one male C. sycophanta, received from Europe in 

 1909, was placed in a jar with a female C. scrutator which was col- 

 lected in Washington, D. C.,in 1909, and hibernated here the following 

 winter. The male emerged from hibernation June 1 and the female 

 June 5. June 21, 8.30 a. m., Mr. Culver noted that the pair had been 

 attempting copulation for the last half hour. At 8.40 a. m. the male 

 succeeded in his attempt at copulation and remained in coitu until 

 8.43. June 22, 2.48 p. m., Mr. Culver again observed the pair in 

 copulation, and watched them for 7 minutes before they parted. 

 June 23, 1 small egg was found, and on June 25 several eggs were 

 noted in the jar. July 12, none of the eggs had hatched. Jar cleaned 

 out. July 25, the male sycophanta was removed from the jar, and 

 a male scrutator added instead. July 29, female scrutator died. No 

 eggs were laid after the male scrutator was added. 



Another experiment was conducted as follows: June 16, 1910, a 

 female sycophanta emerged from hibernation. The cage was dug up 

 on June 23, but no male was found. The pair were pupae in the 

 fall of 1908 and the female did not reproduce in 1909. June 23, 

 a male scrutator was added which was collected at Onset, Mass., 

 August 3, 1909, and brought to the laboratory. This male was kept 

 in a jar with one female which produced 22 larvae that year. Infertile 

 eggs were seen in the jar containing the female sycophanta on the 

 date the male was added, but the latter paid no attention to the 

 female. June 27, infertile eggs in jar; jar changed. June 28, infertile 

 eggs in jar; jar not changed. June 29, infertile eggs in jar; jar 

 changed. June 30, 2 p. m., the male attempted copulation with 

 female sycophanta three times but was unsuccessful, although the 

 latter stood quietly and attempted to facilitate the operation as much 

 as possible. July 1, 2, 3, 4, and 8, eggs on surface; jar changed. 

 July 9, male scrutator died. Male sycophanta added, copulation took 

 place immediately, and on July 14 larvae hatched from the eggs 

 deposited in the jar. 



In the above experiments with the two species, copulation was 

 attempted and unions effected apparently with difficulty, but all of 

 the eggs were infertile. 



Habits of Flight. 



Few notes have been secured on the flying ability of this species. 

 In the colonies the beetles have been frequently seen running about 

 or climbing the trees, and they often drop from the branches to the 

 ground without making any effort to fly. 



