.MIT. 23. BLISTER BEETLE IRICRANIA PARKER .\ND BOVING. 9 



homogeneous, transparent substance that in chemical composition 

 seems closely related to chitin (fig. 36). In the bottom of this cell 

 the bee places a quantity of food composed of honey and pollen 

 mixed into a sticky semi-fluid mass. Then within the cell she de- 

 posits an egg attaching it by one end to the side of the cell wail 

 above the food mass (lig. 36.) The parasite within the cell can, 

 therefore, readily reach the ogg without coming in contact with the 

 food at all. 



A^^ien the Meloid larva gains entrance into the cell of Golletes it 

 attacks and devours the egg of the bee. This is the normal pro- 

 ceedure but it is not absolutely necessary that the parasite, in order 

 to survive, make its first meal upon the egg of the host. For we 

 reared one parasite in the laboratory from egg to adult wholly upon 

 the food (pollen and honey) provided by the bee for her offspring. 

 By devouring the egg of the host the parasite in addition to obtain- 

 ing a nutritious food performs an act of self-preservation ; for if the 

 egg of the host were permitted to hatch and the young survive, the 

 quantity of food available would be insufficient for the two larvae 

 and both would perish. If the beetle is to survive, the egg of the 

 host must be destroyed. The food thus derived from the egg of the 

 host is sufficient for the development of the first instar. During this 

 period of development the larvae expands greatly so that the chi- 

 tinized rings of the abdomen are widelj^ separated and its length in- 

 creases to nearly double that of the instar on its emergence from the 

 egg (fig. 37). After the first moult the body of the larval beetle 

 assumes a boat-shaped form with the spiracles placed dorsally, for 

 the larva, which normally while in its first stage remains on the side 

 of the cell, now rests directl}^ upon the food mass and its shape is 

 such that it floats safely upon the semi-fluid food in much the same 

 manner as a duck floats on water (fig. 38). This same position with 

 relation to the food mass is maintained by the following third in- 

 star (fig. 40), but b}?^ the time the fourth instar is reached so much 

 of the food has been consumed and the larva has grown to such size 

 that it may now safely assume any position in the cell that may be 

 necessary to enable it to obtain all the food remaining (fig. 41). 



On the morning of June 9, 1920, a number of brood cells of 

 Golletes was obtained from the nesting gi'ound each of which con- 

 tained a parasite in the first stage. In six of these the parasites were 

 still feeding on the egg of the host and these molted for the first 

 time as follows: 2 on June 14; 1, June 15; 2, June 17; and 1, June 20. 

 In regard to six others the egg of the host had already been com 

 pletely devoured and molting took place as follows: 1, June 9 (at 4 

 o'clock in the afternoon) ; 1, June 11; 1, June 12; 1, June 14; and 2, 

 June 17. From the data given above it is evident that the time re- 



