..iiT. 23. BLISTER BEETLE TEICRANIA PARKER AND BOVING. 5 



were placed in the field on April 1. They began hatching on April 

 25. These eggs were placed in the field on the imder side of a piece 

 of dried cow dung, on which they had been deposited, and then were 

 kept during the period of incubation under conditions as nearly 

 normal as possible. While these eggs were in the field frosts were 

 frequent at night in the early part of April and on one night the 

 ground was slightly frozen. 



In 1917 the beetles appeared in the field in large numbers on April 

 12, indicating that this was the time of maximum emergence, and 

 eggs that year were found hatching in the field on May 12. "Wlien 

 these eggs were deposited is not known, but when other facts to- 

 gether with the meager data actually obtained are taken into con- 

 sideration the probabilit}^ is great that their period of incubation 

 covered approximately one month. However this may be, enough 

 was learned in these investigations to show that, since the beetles 

 normally emerge and lay their eggs a certain length of time before 

 the host emerges and begins nesting, those factors that retard the 

 hatching of the eggs also retard the emergence of the bees, so that 

 when the first larval instars do appear the bees are providing in 

 their nests the food required by the beetle for its survival as a 

 species. 



Just how long this first instar can svirvive in the field after hatch- 

 ing is not known. T^Hien kept confined together in numbers in the 

 breeding jars in the laboratory none survive for a period greater 

 than 11 days. Wlien kept together in a small space the larvae are 

 constantly attacking one another, and, although no case was observed 

 in which one larva killed another outright, there can be no doubt 

 that these constant fights and contentions serve to exhaust the larvae 

 sooner than would be the case if they were allowed to scatter about 

 unmolested, a condition that prevails in the field. Furthermore in 

 the laborator}'^ the larvae were without water or food of any kind. 

 In experimenting with them it was found that the first instars will 

 take water when they come in contact with it and will also eagerly 

 sip honey when they first find it. Their power of resistance to the 

 vicissitudes of their environment is very great. It is next to impos- 

 sible to drown them in water. The means for overcoming this 

 danger, probably the greatest they have to face in the field is found 

 in the development of the last pair of spiracles as will be explained 

 in the discussion of the morphology o,4i|ta|^5j^'8|,^., (See p. 17.) 



Just how the first instar gets down into the nest of 'frMr^kost^ has 

 not been positively learned. The eggs are laid in the immec^i'ate 

 vicinity of the nesting burrows of the host and when the larvae 

 emerge from the eggs they immediately scatter about over the ground 

 in every direction. Under these conditions it is possible that the larva 



20183— 25— Proc.N.M. vol.64 42 



