LIFE-HISTORY OF BLISTER-BEETLES. 299 



"while tbey will feed upon those of other species in confinement, I have so far found 

 none in the deeper-necked, nnrrower, more compact egg-pods either of Calo2)tenus femur- 

 rubriim, C. atJanis, or C^dipoda sulphurca, in which the eggs are regularly and quadri- 

 liuearly arranged as in those of C. spretus. 



Not only have I found a large proportion of the egg-pods of C. dlfferentialis naturally 

 infested with these Epicauta larva3, hut I have succeeded in hatching and reariog num- 

 bers in-doors, and have them even at this writing (Octoher 30), by hundreds, in all 

 stages from the first larva to the pseudo-pupa. The larval habits of the genus may bo 

 illustrated by reciting those of one of the species, viz, vitiata. 



From July till the middle of October the eggs are being laid in the ground in loose, 

 irregular masses of about 130 on an average — the female excavating a hole for the pur- 

 pose, and afterward covering up the mass by scratching with her feet. In confinement 

 she sometimes omits both these instinctive acts and oviposits on the surface of the 

 ground. She lays at several different intervals, producing in the aggregate probably 

 from four to five hundred ova, judging from examinations made on the ovaries of some 

 that were gravid. She prefers for purposes of oviposition the very same warm sunny 

 locations chosen by the locusts, and doubtless instinctively places her eggs near those 

 of these last, as I have on several occasions found them in close proximity. In the 

 course of about 10 days — more or less, according to the temperature of the ground — 

 the first larva or triungulin hatches. The hatching takes place without the aid of any 

 rvptor ovi, for the egg-shell is so delicate that it easily splits, from mere expacsion, 

 along the back near the head, and breaks and shrivels up with the escape of the larva. 

 These little triungulius (PI. IV, Fig. 2), at first feeble and iDcrfectly white, soon assume 

 their natural light brown color and commence to move about. At night or during 

 cold or wet weather all those of a batch huddle together with little motion, but when 

 warmed by the sun they become very active, running with their long legs over the 

 ground, and prying with their large heads and strong jaws into every crease and crev- 

 ice in the soil, into which, in due time, they burrow and hide. Under the microscope 

 they are seen to fairly bristle with spinous hairs, which aid in burrowing. As becomes 

 a carnivorous creature whose prey must be industriously sought, they display great 

 power of endurance, and will survive for a fortnight without food in a moderate 

 temperature. Yet in the search for locust-eggs many are, without doubt, doomed to 

 perish, and only the more fortunate succeed in finding appro]3riate diet. Upon the 

 slightest disturbance they curl up in a ball with the head bent pretty closely on the 

 breast. 



Reaching a locust egg-pod, our triungulin, by chance, or instinct, or both combined, 

 commences to burrow through the mucous neck or covering, and makes its first repast 

 thereon. If it has been long in the search, and its jaws are well hardened, it makes 

 quick work through this i)orous and cellular matter, and at once gnaws away at an 

 e^g, first devouring a portion of the shell, and then, in the course of two or three days, 

 suckiug up the contents. Should two or more triungulins enter the same egg-pod, a 

 deadly conflict sooner or later ensues until one alone remains the victorious possessor. 

 By the time the contents of an egg are consumed, the body of the parasite has percep- 

 tibly increased so that the white sutures between the segmental plates show con- 

 spicuously, especiallj' as there is a tendency on the part of the animal to curve its body, 

 and bi:ing the sutures more into relief A second egg is attacked and more or less com- 

 pletely exhausted of its contents, when a period of rest ensues, the triungulin skin 

 splits along the back and there issues the Second Larva (PI. IV, Fig. 4) — white, soft, 

 with reduced legs and quite different in general appearance from the first. This molt is 

 experienced about Iheeighthday from the first taking of nourishment. The animal now 

 naturally lies in a curved position (PL IV, Fig. 4, d), but if extracted from the egg-pod, 

 will stretch itself and move with great activity, reminding one very strongly of many 

 Carabid larvte, for which reason I would designate this as the Carabidoid stage of the 

 second larva. After feeding for about another week, a second molt takes place, the 

 skin, as before, splitting along the back and the new larva hunching out of it until the 



