72 



BULLETIN 417, U. S. DEPARTMENT OF AGRICULTURE. 

 FOOD CONSUMED BY LARV^. 



Daily records were kept of a series of larvae' reared in 1909 and 1910. 

 It was observed that the larvae destroy and consume large numbers 

 of caterpillars in comparison to larvae of Calosoma calidum. Large 

 caterpillars of Malacosoma americana and Porthetria dispar were 

 offered for food. A few records follow: 



Table 18. — Food eaten by larvse of Calosoma reticulatum, 1909, 1910. 



No. 



Date 

 hatched. 



Date 

 ceased 

 feeding. 



Mala- 

 cosoma 

 ameri- 

 cana cat- 

 erpillars, 

 fourth to 

 sixth 

 stages. 



Porthe- 

 tria dis- 

 par cater- 

 pillars, 

 sixth 

 stage. 



Total. 





1909 



1909 



1909 



1909 



1909 



1506A 

 1506B 

 1506C 

 1506D 

 1506F 

 15061 



June 21 



...do 



...do 



...do 



...do 



...do 



July 8 1 

 14 

 12 

 16 1 

 121 

 12 



6 



8 

 5 

 6 



7 

 7 



20 

 31 

 33 

 23 

 29 

 37 



26 

 39 

 38 

 29 

 36 

 44 





1910 



1910 



1910 



1910 



1910 



1506AB 

 1506AC 

 1506AD 

 1506AE 

 1506AF 

 1506AG 



June 13 



...do 



...do 



...do 



June 14 

 ...do 



July 5i 

 2 

 June 30 

 July 4 



5i 

 61 



26 



25 

 24 

 24 

 25 

 24 



22 

 29 

 15 



45 

 35 

 45 



28 

 34 

 19 

 49 

 40 

 49 



1 Full-grown larva died. 2 All sixth-stage caterpillars. 



Very little variation was found between the two series, as an average 

 of 36 caterpillars was destroyed by 6 specimens fed in 1909 and 37 

 by the same number in 1910. The larvae in both series continued 

 their activity and feeding over an average period of 21 days. The 

 same period is required by larvae of Calosoma calidum. 



Three larvae were fed to maturity in 1911 on pupae of Malacosoma 

 americana after the latter had been stripped from their cocoons, and 

 when necessary large caterpillars were substituted. Ten pupae were 

 killed and wholly or partly devoured by the first-stage larvae, nine 

 pupae and three fifth-stage caterpillars by the second-stage larvae, 

 and nine pupae and three sixth-stage caterpillars by the third-stage 

 larvae. Assuming that about the same amount of food was contained 

 in a large caterpillar as in a pupa, an average of 11 to 12 pupae were 

 consumed to complete the larval growth. 



HABITS OF LARVAE. 



During the spring ana summer of 1911 data were collected in an 

 experimental way to determine the climbing habits of these larvae. 



May 29 six young first-stage larvae were tested (PI. Ill), and one 

 of them immediately climbed upon the tree to a height of 5 feet, then 

 fell to the ground. This larva climbed with considerable ease. 

 Another specimen ascended 1J feet before falling. June 5 all the 

 larvae had molted and made no attempt to climb of their own volition 

 while they were under observation. They were put upon the bark 



