52 



Life History 



The egg is white, elongate, 2.5 mm. long, and suspended from 

 the upper side of the cell by a filament of about the same length. 

 One egg is placed in each cell of stored up caterpillars. The egg 

 hatches in but a few days, and the whitish larva at once begins 

 eating its food-supply of caterpillars. It grows rapidly, finishing 

 its food-supply and becoming full grown in o to 7 days. It is 

 then a fat, footless grub (Plate VI, fig. oa) about 15 to 17 mm. 

 long and 5 mm. thick, curved ventrally. In a day or two it 

 spins a layer of whitish silk over the inncn* surface of the cell, 

 not making a regular, close-fitting cocoon. 



Pupation soon takes place. The pupa (Plate \], fig. 5b) is 

 white for several days; finally it gradually turns black a few 

 days before it becomes adult. The pupal period is about 15 days. 

 At times they may pass long periods of time as full-grown larvae 

 in their cells before pupation, prol)ably a provision t(j enable 

 them to survive long periods of drought in some of the 

 drier regions. I found such a larva in a mud wasp's nest, 

 June 5th, 190(>. It remained in this condition in a tube in the 

 laboratory of the experiment station till Dec. Dtli, 1906, when 

 it pupated. This was a period of a little over (i months as a 

 full-grown larva, and there is no knowing how long it had been 

 in this condition when discovered. Pupation took place after 

 a period of about 2 weeks of rainy weather with " Kona" storms. 

 It remained in pupal stage 18 days, when the adult was fully 

 developed. 



Parasite {Agcniaspis sp?) (Plate VI, fig. H) 



Unfortunately the good work of Odynerzis nigripe?mis is much 

 checked by reason of its being parasitized by a very small C'halcid 

 Fly. This parasite I have found widely distributed on Hawaii, 

 Maui and Oahu. In a number of instances I have bred them 

 from O. nigripennis larvae; and much oftener have found in 

 nigripennis nests the empty larval skin from which the parasites 

 emerged. The nigripennis larva(> are allowed to become full- 

 grown; the numerous tiny larvae of the parasite feeding inside, 

 and pupate shortly after the host larva is full-grown. They 

 completely' fill the latter and can be seen through the transparent 

 skin, packed so close that tlie skin has bulges where it conforms 



