AN INTERNAL PARASITE OF THYSANOPTERA. 27 



takable signs of parasitism. Two of these died, but on December 13, 

 from the otlier two, parasitic larvae had emerged and formed naked 

 pupae. These parasitic pupae were sent to Dr. Howard in the hope 

 that the adult could be reared and identified, but unfortunately 

 both died and it was impossible to identify the species. At that 

 time Dr. Howard wrote to the author and advised him of the scien- 

 tific interest attached to this insect, and requested him to make 

 careful collections of the host larvae in order to recover the parasite, 

 if possible. 



This work was immediately taken up, but it was not until the 

 following year, during February, 1911, that the larvae of Heliothrips 

 fasciatus were again found in the field. From that time until July 1, 

 1911, large numbers of the larvaB of this thrips were collected and 

 reared to adults, but in no case was there a sign of parasitism. How- 

 ever, on July 3 one prepupa of Ileliothrips fasciatus gave unmistakable 

 signs of parasitism, but it died before the parasite matured. 



Wliile collecting thrips material at Hollywood, Cal., on June 29, 

 1911, a very minute hymenopteron was observed on the underside 

 of a bean leaf in company with larvae of this same thrips ; and wliile 

 it was being carefully examined through a small hand lens it appeared 

 to oviposit once in a thrips larva. After this, as the insect was not 

 again observed to come into contact with thrips larvae, it was cap- 

 tured and put in 50 per cent alcohol. Wlien the minute size of this 

 insect was taken into consideration, it was at once evident that the 

 single case of apparent oviposition must be more or less doubtful, 

 and that it was very essential that the insect be reared to support 

 this observation. This was actually accomplished on July 29, 1911, 

 when an adult of this same species was reared from a larva of Ilelio- 

 thrips fasciatus, collected at HollyAvood on June 29, 1911. From then 

 until November this parasite has been collected and reared in large 

 numbers. 



CLASSIFICATION AND ORIGINAL DESCRIPTION. 



Thripoctenus russelli Crawford is a minute insect belonging to the 

 hymenopterous family Chalcididae and to the subfamily Tetrasti- 

 chinae. Mr. Crawford ^ has erected a new genus and species for tliis 

 insect. He places the genus near Winnemana, but separates it 

 from the latter by the absence of two longitudinal grooves on the 

 scutellum. 



The following technical description of the genus and species is 

 taken from Mr. Crawford's paper: 



Bolons^s to the tribe Tetrastichini; antennre with two joints in the funicle, one very 

 small ring joint, club three-join tod, the joints fused; i)arai)sidal furrows indistinct, 



' Loc. cit. 



