48 ENTOMOLOGICAL NEWS. [Feb., '05 



they both adopt the same method of depositing their eggs on 

 the egg of their host Ccratina dnpla. But in the development of 

 the larva at the expense of the egg or larva of the bee, each 

 of them pursues a different course. The larva of Grotea 

 anguina first increases its size by taking up the contents of the 

 egg or young larva of the bee, but it is still rather small and 

 feeds for several days on pollen and nectar before undertaking 

 the task of breaking through the partition into a neighboring 

 cell in search of a bee larva for food. It starts out as a carni- 

 vorous larva, thereupon it passes over to the diet of a vege- 

 tarian, and finally returns to carnivorous habits. Habrocyptus 

 gfu-nicJieri, on the other hand, does not destroy the egg of the 

 bee, and furthermore it spares the life of the bee larva until the 

 latter has reached a considerable size. During more than one- 

 half of its larval existence it partakes of a very small amount 

 of food, derived superficially from the egg or the larva of the 

 host, and it grows extremely slowly. But finally, by killing the 

 bee larva and feeding on its contents it enters a period of rapid 

 growth, and later on it invades one or more of the bee cells in 

 pursuit of prey in exactly the same manner as does the larva 

 of Grotea anguina. The time necessary to complete the growth 

 of the larva is about the same in either of the species, being 12 

 or 13 days, but in the later development there is a great differ- 

 ence between the tw^o. After completing its cocoon, the larva 

 of Grotea anguina remains as a so-called resting larva in a 

 state of inactivity until the spring of the following year, when 

 it pupates, and appears as a mature insect at about the time 

 the Ceratlna bees start to build their nests. During this entire 

 period, lasting at least 10 months, the resting larva might 

 suffer injury from different sources (attacks of parasites, 

 inclemency of the weather, etc.) if not properly protected, and 

 we understand the importance of the strong defensive parti- 

 tions erected at the upper and lower end of the cocoon cham- 

 ber. Furthermore, the parasite does not always deposit its 

 egg in the lowest cell, but sometimes as high up as the jth 

 cell, as observed in one of the nests. In such a case there may 

 be several young bees emerging from the lower cells in late 

 summer. These, in order to leave the nest would have to break 





