1906] 
UIKA ULT—TRICUOGKAMMA PRETIOSA RILEY 
137 
TIUCHOGRAMMA PRETIOSA RILEY. (JVIROSITIOX A RESUMpi 
.\LF.C. AR.SE.NK GIRAVI.T, WASHIXGTOX, 1). C. 
Lintner ( 1S83), in I’syclie, lias given an accurate and .somewhat detailed account 
of the oviposition of tliLs minute and very interesting egg-parasite, which ha.s also 
been co])ied verbatim in his second report on the injurious and other insects of the 
state of N'ew York (Lintner, 188.')). The host was IReronun n’6e.9?fSeopoli, formerly 
Ncmatus renirirosus Klug. 
This is the first account of its oviposition published, and although lacking in many 
details, the best one so far placed on record. ( )thers have observed and briefly 
recorded this habit. Riley (188.5), ([noting Hubbard, states briefly that the mother 
parasite works chiefly by day, dej)ositing two ova in each egg of Alabama or lleliothu-, 
often, but a single adult emerged from the host eggs, and occasionally three were 
obtained. Nothing is said in regard to the manner of ovij)osition. P\ W. Mally 
(1902), briefly states the manner of oviposition, with some details; probably he had 
not seen Lintner’s account. The host was llelwlhis obsoleta PYbricius, and the 
account is accurate .so far as given. P'inally, (.^uaintance and Brues (1905), give a 
brief, eondenscal account of its ovijjosition, as a result of recent studies. The fol- 
lowing is but an enlargement of their account. 
During the recent investigations on the cotton bollwonn {Hcliothbf obsoleta 
P"abr.) by the I'nited States Department of Agriculture, in Te.xas, during 1904 the 
writer had occasion, in studying its ])arasites in the laboratory at Paris, to make 
detailed studies on this species of Trichogramma, the most common and useful of 
the many parasites attacking that important pest. Hundreds of si)ecimens were 
reared in confinement, and ample o[>portunity offered to observe its habits closely. 
As shown below, specimens were ])laced on the stage of the microscope, and there 
watched at leisure, while they ran fnisily about among the host eggs, depositing into 
them. 
These observations but serve to confirm those made by Lintner; and it is through 
the kindness of Dr. L. (). Howard, f'hief of the Bimniu of Entomology, that the 
writer is able to offer these more detailed notes on this little egg-[)arasite. 'I'hey are 
also offered as an addition to our knowledge of the habits of the smaller ])arasitic 
Hymenoj)tcra, and to sum uj), as it were, what is now known in regard to the ovij)osi- 
tion-habit of pretiosa. P'urther results of the studies on this in.seet will be offen'd a.s 
time permits. 
