22 MISC. PUBLICATION 241, U. S. DEPT. OF AGRICULTURE 
MYIOCEPHALUS BOOPS (Wesmael) 
(Figs. 1, G; 2, D 
Microctonus boops Wesmael, Monographie des Braconides Belgique, p. 59, 1835. 
Gamosecus laticeps Provancher, Additions et Corrections au Volume II de la 
Faune Entomologique du Canada traitant des Hyménoptéres, 1886, p. 126. 
Microctonus laticeps Provancher, Additions et Corrections au Volume II de la 
Faune Entomologique du Canada traitant des Hyménoptéres, 1888, p. 379. 
Myiocephalus boops Marshall, in Andre, Species des Hyménoptéres d’Europe & 
d’ Algérie, v. 5 bis, p. 218, 1897. 
The writer has studied both the type of boops, which is in the 
Academy of Sciences at Brussels, and that of laticeps, which is in the 
Provincial Museum at Quebec, and is of the opinion that the two are 
conspecific. | Soy yey 
The following description, together with the generic diagnosis given 
above, will readily distinguish the species: 
Length about 3.5 to 4 mm. Clypeus strongly convex, the basal foveae un- 
usually large and distinct; face broad, minutely granular and opaque; malar 
space longer than basal width of mandible, longer in male than in female; frons 
finely granular, with some weak transverse striae below median ocellus; antennae 
longer than the body, about 30-segmented; vertex finely coriaceous; thorax mostly 
finely shagreened; propodeum indefinitely finely sculptured, with a weak median 
carina basally and with carinae bounding the impression on posterior face; first 
abdominal segment very narrow, with conspicuous glymmae at base; ovipositor 
sheaths a little shorter than first abdominal segment. Head yellow, vertex 
broadly black, antennae dark brown, scape and pedicel yellowish; thorax black 
above, yellow on sides and below; first abdominal tergite blackish, remainder of 
abdomen yellowish brown; legs entirely yellow; wings hyaline. 
The writer has seen only 3 North American specimens, the type 
of laticeps and 2 specimens in the National collection, a female from 
Ottawa, Canada, and a male from Stony Island, N. Y., the latter 
collected July 8, 1896. 
The host is unknown. It should be noted, however, that Morley 
has recorded falconivibrans from a nest of Formica rufa Latr. 
The Genus SYNTRETUS Foerster 
Perilitus Haliday (Sectio C), Ent. Mag. 3: 38, 1835. 
Microctonus Wesmael (in part), Monographie des Braconides Belgique, p. 54, 
1835; Westwood, An Introduction to the Modern Classification of Insects, 
v. 2, Gen. Syn., p. 61, 1840; Marshall, Ent. Soe. London Trans. 1887: 81; 
Ashmead, U. S. Natl. Mus. Proe. 23: 116, 1900; Viereck, U. S. Natl. Mus. 
Bul. 83: 94, 1914. | 
Syntretus Foerster, Verhandl. Naturh. Ver. Preuss. Rhcinlande 19 (N. F. 9): 251, 
1862; Szepligeti, Hymenoptera. Fam. Braconidae, in Wytsman, Genera 
Insectorum, fase. 22, p. 172, 1904. (Genotype, Microctonus vernalis 
Wesmael.) 
When Foerster described Syntretus, in 1862, he named Microctonus 
vernalis Wesmael as type. At the same time he designated Perilitus 
aethiops Nees type of Microctonus Wesmael. This was the first 
valid type fixation for Microctonus, Westwood’s designation of 
Perilitus idalius Haliday, in 1840, being unacceptable since that 
species was not originally included. Nevertheless, the name Microc- 
tonus has been generally employed for the group which is typified by 
udalius and vernalis rather than aethiops, Syntretus having been treated 
as a synonym. Only Szepligeti appears to have used Syntretus 
properly, as the valid name for this group, but he left the identity 
of the true Microctonus in doubt. As late as 1914 Viereck named 
Microctonus vernalis type of Microctonus, disregarding Foerster’s 
