24 MISC. PUBLICATION 174, U.S. DEPT. OF AGRICULTURE 



or a little broader than long, longitudinally striated, with a slight transverse 

 prominence at base, and clothed with long hairs ; second tergite a little longer 

 than the following tergites combined, polished, the two basal foveae short and 

 smooth and pilose at the bottom, the rest of tergite bare; tergites beyond the 

 second subequal, smooth, and each with a transverse row of hairs ; first sternite 

 hairy, the second bare, following sternites with a transverse row of hairs. 



Color black, more or less shining ; antennae brownish black, the flagellum 

 frequently brownish testaceous ; mandibles reddish ; legs brownish black, the 

 front tibiae and more or less of their femora usually reddish ; pubescence 

 grayish except the tuft of hairs on scutellum which is yellow ; wings very 

 slightly fuscous. 



Male. — Length 1.5 to 1.9 mm. Antennae not distinctly clavate, the flagellar 

 joints all of approximately the same thickness ; scape subequal to the five 

 following joints together ; pedicel about twice as long as broad ; first flagellar 

 joint shorter than pedicel, about one and one half times as long as broad at 

 apex, its apex as broad as apex of pedicel but its base! much narrower ; second 

 flagellar joint longer than the first joint and a little longer than pedicel, 

 cylindrical with its apex obliquely truncate ; third flagellar joint a little longer 

 than broad, subtriangular, distinctly shorter than second ; fourth to seventh 

 joints subequal, nearly cylindrical, and about one and one half times as long 

 as broad; apical joint conic-ovate and approximately twice as long as the 

 preceding joint. Abdomen a little broader than the thorax, broadly rounded 

 at apex, the second tergite usually with a few very weak and short striae at 

 base. Otherwise like the female. 



Described from 10 specimens reared from Phytophaga destructor 

 in France by P. Marchal and 4 specimens reared from the same host 

 insect by T. Cheviroff, Leningrad (St. Petersburg). 



REVIEW OF LITERATURE 



This species was described under the name Platygaster remains 

 by Walker in 1836 from specimens collected on grass near London, 

 England. In 1856 it was transferred by Foerster to his genus Trich- 

 acis along with two other species. In 1897 Ashmead identified as 

 T. remulus specimens which had been reared by Marchal from the 

 hessian fly in France and during the same year Marchal published a 

 very interesting account of the postembryological development of the 

 species. MarchaFs paper was reviewed by Howard the following 

 year, and this review was quoted by Osborn. The species was re- 

 described and figured in 1900 by Pospjelov, who recorded it as a 

 parasite of the fly in Russia. In 1906 Marchal recorded further 

 detailed studies on its embryology, and in the same year Kieffer 

 redescribed it from specimens transmitted to him by Marchal. It 

 was recorded as a parasite of the fly in Poltava, Russia, by 

 Znamenski in 1923, and in 1929 Meyer again mentioned its occur- 

 rence in Russia. Kieffer included it in his monograph of the family 

 Scelionidae in 1926, and in giving its distribution mentioned only 

 England and France. Hans Blunck in 1931 recorded the species 

 as a parasite of Mayetiola phalaris Barnes in Pomerania. 



One specimen of the series from which the foregoing description 

 was drawn is without much doubt a part of the material upon which 

 Ashmead based his determination of the species for Marchal. The 

 other nine specimens from France were reared by Marchal at Blois, 

 France, in March 1903. These were not seen by Ashmead but were 

 identified by Marchal himself, and were sent to L. O. Howard in 

 1921 and by him turned over to the present writer. They undoubt- 

 edly constitute a part, at least, of the material upon which Marchal's 

 later biological notes on the species were based. Nothing is known 

 of the history of the Russian specimens. 



