I 

 INSECT CONTROL 307 



of one hundred pupae eaten, out of a large number made 

 up of equal proportions of both sexes, seventy-five and a 

 half per cent, were females as against twenty-four and a 

 half per cent, of males. As every female pupa case 

 contains a potential mother moth, the wisdom of nature 

 in endowing Calosoma with its predilection is self-evident. 

 These larvae will also catch and kill adult female gipsy 

 moths, which, being too heavy and clumsy to fly, fall an 

 easier prey than would otherwise be the case. The adult 

 beetles are scarcely less voracious than their larvae ; they 

 climb the highest trees, going out to the branches, twigs, 

 and even leaves in search of caterpillars, which they eagerly 

 devour after having nipped them in the middle of the 

 back. If disturbed in their work, the beetles instantly 

 fall to the ground and hide till the danger, or supposed 

 danger, has passed. 



One of the experiments carried out by the American 

 entomologists is well worth recording here. It has been 

 mentioned that Calosoma and its larvae will not accept 

 substitutes in the way of food, and it is hardly necessary 

 to add that food is necessary, even to a beetle, for proper 

 development. These questions then arose, Could the larvae, 

 on being turned loose in a new land, obtain their own food, 

 and how far could they travel in search of it ? To answer 

 these questions, a young larva was taken when just hatched 

 and a record kept of its travels till it died, no moisture 

 or food being supplied throughout the experiment. For 

 recording purposes, a small table three feet eight inches 

 long by two feet wide was fitted 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 (fig. 96). 

 Beneath the roll was placed a piece of stiff paper, which 

 extended beyond the sides of the paper connected with the 

 reels, and the edges were bent upwards, so as to prevent 

 the escape of the larva from the sides of the table. The 

 paper on the reels was eighteen inches wide. The larva 



