12 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 64. 



In every case in our study of the life-history of this insect, where 

 we followed out the transformations of the individual from ess to 

 adult, these transformations occurred within a period of time ex- 

 tending from April to September, and in every case also the beetle 

 did not rupture its protecting case composed of its cast fourth and 

 fifth skins till it emerged as an adult insect, Wliether so slight 

 a change in the normal course of events as that caused by the removal 

 of this individual from the cell of the bee before it had reached the 

 pupal stage was responsible for the unusual behavior of this larva, 

 or whether this departure from what seems to be the normal course 

 of events in the process of development represents a return to a more 

 primitive stage in the insect's life-history, we are unable to say. 



PART 2. 



MORPHOLOGY AND TAXONOMY. 



A. EGG. 



On page 3 an account has been given of the way in which the 

 egg masses are distributed and cared for by Tricrania, the number 

 of eggs deposited has been given, as well as the size, shape and 

 color of the individual egg. 



In the Nemo gnat hinae the act of caring for the safety of the 

 egg masses is more neglected than in the other blister beetles whose 

 females dig a 3-5 mm. deep thimble or bell-shaped cavity in the 

 soil and deposit one or two egg masses at the bottom of it. Thus 

 Sitaris inuralis, Apalus himaculatus, and Stenoria ancdis lay their 

 eggs as an uncovered pile in some little groove in the galleries 

 of the host bee, and Sitaris rufiqjes^ Sitaris solieH, Nemognatha 

 chrysomelina, and Zonitis hilineatus ^ deposit their sometimes rather 

 numerous egg masses on the leaves or stems of different large herbs. 

 To place the egg masses under small stones or dry cow dung, as 

 Tricrania does, is the simplest way recorded in this group of caring 

 for them. 



The total number of eggs laid by a single female varies much 

 in the Meloids, ranging from about 50 in some of the species of 

 Zonubris to about 2,000 or more in genus Meloe. The Nemognathi- 

 nae deposit as many as Meloe. 



The proportional size of the single &gg depends on the number 

 of eggs laid, being comparatively large, from 2-3 mm. in forms 



* Two egg masses of Zonitis hilineatus were collected by A. N. Caudell, Bureau of Ento- 

 mology, on underside of one loaf of Vcrhesina occidentalis growing near Fletcher's boat- 

 house, south side of Georgetown Canal, Washington, D. C, Aug. 14, 1917. Other egg 

 masses identical to these, from which larvae hatched Sept. 1, 1917, were collected at the 

 same place and on the .same plant species about IJ inches from a si>ent female of Zonitis 

 bilineatua, by H. S. Barber, Bureau of Entomology, Aug. 24, 1917. All egg masses are 

 preserved in the U. S. National Museum. 



