30 CALOSOMA SYCOPHANTA. 



footing. Not only do the larvae secure a part of their prey in the 

 trees, but they molt in crevices of the trunks and branches to a con- 

 siderable extent. This habit is so general that it has been possible 

 to determine quite accurately the dispersion of the species by exam- 

 ining trees for molted skins outside the areas where colonies have 

 been liberated. This work can be done even after all larvae have 

 entered the ground for pupation, so that the time when satisfactory 

 investigations ca*n be made extends over the greater part of the 

 summer. Trees in the gipsy moth infested sections which have 

 been burlapped are favorite resorts for the Calosoma larva?, as they 

 find plenty of food available and are protected in a large measure 

 from enemies that might destroy them. (See PI. VI.) To determine 

 the distance that larvae of this species will climb, the following 

 observation was made at West Gloucester, Mass. July 30, 1908, 

 a number of larvae was liberated in woodland and several were 

 placed at the base of a red oak tree about 10 inches in diameter. 

 Two of these larvae immediately commenced climbing the tree. 

 One ascended to a distance of about 10 feet and as no food was present 

 it retraced its steps and returned safely to the ground. The other 

 continued its journey up the tree. At a distance of 15 feet from the 

 ground the bark became very smooth and offered little opportunity 

 for the insect to obtain a safe footing. It continued to climb, how- 

 ever, until it reached a point about 25 feet from the ground, where 

 it lost its hold on the bark and fell. There is no doubt that 

 these larvae often climb nearly to the tops of rough-barked trees, 

 particularly white oak, in search of food. Several cases hav6 been 

 noted where molted skins were found at least 20 feet from the ground, 

 and they have been observed in masses of pupae on the underside of 

 branches near the tree trunk. The clim])ing habit of the larvae is of 

 great importance, as it increases the opportunity for the development 

 and usefulness of the species. 



Distance Traveled by the Larva. 



Inasmuch as young larvae of this species must be able to find suit- 

 able food in order to develop, the question of their ability to travel is 

 one of great importance. It seemed desirable to test this matter and 

 plans were made and apparatus constructed for the purpose. A 

 young larva was taken which had just hatched, and a record kept of 

 its travels until it died, no moisture or food being supplied throughout 

 the experiment. In order to secure this record a small table 3 feet 8 

 inches long by 2 feet wide was equipped with spools at each end near 

 the top so that a roll of paper could be reeled across the top of the 

 table by turning the spools. (See fig. 14.) Beneath this paper was 

 placed a piece of stiff wrapping paper which extended beyond the sides 



