THE GENUS CALOSOMA. 33 



HABITS OF LAKV^. 



Experiments were tried with larvae of this species in all stages to 

 secure data on their habits of fmdmg food, using the apparatus showT' 

 m Plate III. 



June 24, 1912, Mr. Dudley began an experiment with two first- 

 stage larvse. They were placed several times upon the bark of the 

 tree, as they did not seem to venture there of their own volition. 

 When this was done they would either f aU to the ground or advance 

 to the nearest loose scale of bark in their path and remain there until 

 disturbed. 



June 26 and 27, the two larvae molted to second stage. They 

 acted in a similar manner in this stage. They were usually found 

 buried in the earth in the morning instead of in the food cage at the 

 top of the tree. 



On July 2, one larva died in the second stage and the other molted. 

 The third-stage larva was put upon the bark of the tree several times 

 and would climb 6 to 12 inches around or down the tree before falling. 

 This larva became rather sluggish by July 12 and was removed from 

 the experiment. 



July 16, the junior writer hberated two large third-stage larvse in- 

 side the circle, and observed their movements at intervals for two 

 days, after which time they were becoming exhausted from lack of 

 food. One larva, when placed upon the trunk, ascended 12 inches 

 before f allhig, which was the best record for distance covered during 

 the period of the experiment. 



These experiments were repeated in 1913 with practically the same 

 result, except that in one case a first-stage larva after being placed 

 upon the tree was able to chmb about 4 feet before falling. This is 

 the best record made by any larva of this species but hardly indicates 

 that the species commonly chmbs to any marked extent. 



The movements of these larvae are very similar in all stages to 

 those of C. calidum and C.frigidum. It was necessary to remove the 

 larvae from the experiment at intervals in order for them to feed, in- 

 dicating that this species must secure food on or near the ground. 



COLONY AND CAGE EXPERIMENTS IN GREENHOUSE. 



During th(! early spring of 1910 it was necessary to secure lepidop- 

 torous larvie witli wliich to feed specimens of Calosoma and Carabus 

 after their emei-gence from hibernation. After much inquiry, a sup- 

 ply was found in a range of greenhouses at Brighton, Mass. The 

 proprietor is a wholesale grower of roses, A/^paragus sprengeri, and 

 Asparfigvfi pluraosufi and his greatest insect pest on aspai-agus is a cut- 

 worm, jVortua clan/hMina Harr. There are several generations 

 arjiiuaUy and the proprietor and foreman report that the worms can 

 be fouful in various stages during most of the year. The proprietor 

 n-soi-ts to pr)is(jnf'(J bran mash and hand picking to combat the pest. 

 lie <laijiis an annual loss of S2,500 from tliis insect which includes 

 •SI, 000 expended for hand picking at night and other methods, and 

 SI ,oOO damage as a result of th(! cutting off of the tender terminals of 

 the plants, which ch(!cks their growth. 



Cutworms collected by the laborers at night were us<h1 to HmhI 

 Culosf)ma anrl ('arabns. In return for this act of kin(hi(^ss in foiwiinl- 

 ing Ihcni (hiily to th<^ laboratory during the early spring, an expori- 

 54880"— Dull. 417— 17 3 



