106 PSYCHE [October 
OLIGOSITA AMERIGANA ASHMEAD SPECIES NOVA, A NEW CHAL-— 
CIDOID OF THE FAMILY TRICHOGRAMMIDAE FROM 
ILLINOIS. 
BY A. A. GIRAULT, UNIVERSITY OF ILLINOIS. 
I HAVE been requested to draw up the following description of a species of 
Trichogrammidae, which, though undescribed, has been mentioned in the literature 
for several years past, in fact as far back as 1903. It is the first species of the genus 
Oligosita Haliday (Walker) to be described from North America and is parasitic on 
jassid eggs, as will be shown later. In 1903, Professor F. M. Webster published a 
brief paper entitled Some Insects Inhabitants of the Stems of Elymus canadensis 
(Webster, 1903 a) in which it is stated in regard to this species: 
“*Oligosita americana Ashmead MS. nov. sp. Also reared from same species 
of grasses from Princeton, Ind., and in connection with Eurytomocharis eragrostidis 
Howard, at Urbana. ‘This is the first time this genus has been recorded in America.” 
The species is marked with an asterisk to show that it also was reared from 
Elymus virginicus and the original rearings were made at Urbana and Champaign, 
Illinois, in connection with studies on species of Tsosoma inhabiting the stems of 
various grains and grasses. In this way, the parasite became connected with Isosoma 
as host, and in the same year, Webster (1903 b) recorded it definitely from the eggs of 
Isosoma hordei (Harris) in these words: “There is little doubt that Oligosita ameri- 
cana Ashm. and Polyneura citripes Ashm.' both attack and destroy the eggs, as I 
have reared them in numbers from stems of Elymus inhabited by the larvae, and also 
the stems of other grasses inhabited by other Isosoma larvae.” (p. 33). Webster 
adds further, in connection with Isosoma grande (Riley), “not with certainty from 
Isosoma grande Riley,’ and also he indicates it to be an egg-parasite of Isosoma 
tritici (Fitch) and I. captivum Howard. ‘The hosts of the parasite were therefore 
listed in accordance with the foregoing by Girault (1907). So far as I am able to 
find, it has not been mentioned again in the literature. 
Recently, I have been informed by Mr. R. L. Webster of Ames, Iowa, who reared 
the species at Urbana, Hlinois in 1905 from the eggs of a jassid determined by Herbert 
Osborn as being those probably of Dorycephalus platyrhynchus Osborn, that its 
previous record from the eggs of species of Isosoma by the elder Webster (1903; 
1 Polynema citripes Ashmead, a nomen nudum . 
