50 



that t}iif< is a very valuable fly, as it is very abundant at times on 

 some of the above hosts. 



The maggots or larvae of this parasite feed witliin their living 

 host caterpillars, but do not get their full-growth until after the 

 caterpillar has pupate(l. I never have found more than one 

 parasite per caterpillar, in this species. It does not escape from 

 its host to form a puparium as the f()rmer species does; but forms 

 its puparium withiii tlie pupa of its host, after having consunie<l 

 all the juices of the latter. The puparium of this species differs 

 from that of the former, in being larger, and in having two 

 trihjbed black protul)erances on tlie posterior end, wliich is usual- 

 ly somewliat widened and V)lunt. The adult tiy emerges in al)out 

 15 to 20 days after the pupation of its host. In two instances 

 where the host pupa was opened in order to make observations 

 on the maggot of the parasite, it was found that the adult fly 

 emerged in 11 and 14 days, respectively, from the time its 

 puparium was formed. , , 



Odyncrus nii^ripcnnis (Holmgren). (Plate VI, fig. .I.) 



"Black, the wings infuscate, and with a blue (but not bright) 

 iridescence. A small median spot behind the antennae, and another 

 behind each eye, often flavous. Apex of clypeus depressed, and lightly 

 emarginate. Mesothorax finely, but very densely rugosely-punctate, the 

 punctures generally rather large in the $ . Post-scutellum with a very 

 distinct raised line (usually serrulate or spinulose) at the truncation, 

 Propodeura rough with large, feebly impressed, punctures. Abdomen 

 with the second segment not raised from the base ; beneath, with a wide 

 depression, but shallow, meeting the apices of the costae obliquely, the 

 costae themselves more or less obsolete or indistinct." [Perkins, Fauna 

 Hawaiiensis, I, Pt. I, p. 70, 1899.J 



There are more than 100 species of wasi)s of the genus Odynerus 

 which are peculiar to the Hawaiian Islands. This black species 

 is one of the largest ones. It is distributed to all the islands from 

 Oiihu to Hawaii, and occurs from the coast up as high as 4,000 

 feet in the mountains. Like tlie other menil)ers of the geiuis, 

 they store up caterpillars of medium sized lA-pidoptera as food for 

 their young. Their nests are made in hollow twigs or holes in 

 trees, in holes in rocks, in burrows in earth l)anks, etc., accord- 

 ing to what is convenient in the jiarticular locality. A favorite 



