70 CALOSOMA SYCOPHANTA. 



NATURAL ENEMIES OF C ALOSOMA SYCOPHANTA. 



During the sumnier of 1906 the remains of several dead Calosonia 

 beetles were found under conditions which would indicate that the 

 insects had been lulled by some predatory enemy. In fact, one 

 report reached the laboratory that a hairy woodpecker had been 

 observed feeding on C syco'phanta. The localit}^ where this observa- 

 tion was made was visited by Messrs. Titus and Mosher, and wing 

 covers and fragments of legs and bodies of the species were found under 

 a pine tree. Nearby was a nest of young crows, and it is probable that 

 they were responsible for the trouble. 



It is a well-known fact that crows feed on various species of carabid 

 beetles, and specimens of native Calosoma have been found in the 

 crops of these birds by various investigators, so that it would not be 

 strange if they destroyed some of the imported ones. 



In the fall of 1909 a report was received that birds, presumably 

 crows, were destroying the beetles, as a number of fragments of the 

 latter had been found on the ground in woodland near North Saugus, 

 Mass. No absolute evidence was secured to prove that this was the 

 case. 



During the summer of 1910 Mr. H. S. Barber observed that several 

 crows seemed to be loitering about in a locality where the larvae of 

 C. sycophanta were common under burlaps. None of the birds was 

 seen in the act of feeding but the persistence which they exhibited in 

 frequenting the locality aroused the suspicion that tlieir mission was 

 not a friendly one. 



During the summer of 1907 all the dead Calosoma beetles that 

 arrived in the sliipments were isolated to determine whether parasites 

 of any kind would develop, and of 584 beetles which were treated in 

 this way, not one showed evidence of parasitic attack and no parasites 

 were secured. 



In rearing Calosoma beetles it is always necessary to guard against 

 the accumulation of dead or decaying material. If such matter is 

 permitted to accumulate in the rearing jars, the earth soon becomes 

 infested with mites, which later attack the larvae, or even the adult 

 beetles. Probably in nature these insect enemies of the beetles do 

 them no harm, as the conditions are not favorable for the increase of 

 the mites. 



During the summer of 1908 several jars became badly infested with 

 a species of mite which was determined by Mr. Nathan Banks, of this 

 bureau, as Tyroglyphus armipes Bks. The beetles were treated with 

 carbon bisulphid, a small amount being applied with a brush to the 

 underside of the thorax and abdomen, where tlie mites attach them- 

 selves most frequently. 



The beetles survived the treatment perfectly, and after it had been 

 repeated once or twice all the mites were destro)^ed. Several beetles 



