1912] Brazilian Ichneumonide and Braconide 227 
The three species of Heterospilus here described may be 
distinguished as follows: 
1. First segment of abdomen as long as broad at tip; abdomen conspicuously 
bandeditwath Vyellowt dicis.cir tree mockertact ie lect sista tiel srous a/erete H. fascitventris 
First segment distinctly shorter then broad at tip; abdomen black, more or 
[SENSEI VISWEN S192 1S Se anereneT arin ths Gs eidioric Alc k 130 > aie See ate ee 2 
2. Ovipositor as long as the abdomen; first section of the radius much shorter 
thanerhewsecond) abdomen placa trainin icra HT. meridionalis 
Ovipositor scarcely more than one-half as long as the abdomen; first section 
of the radius as long as the second; abdomen rufous on the first segment 
anGdepasalehali oft the Seconda. :).loen acre eters oer aoe ts H. dubitatus 
Family ALYSIIDz 
Idiasta nigripennis sp. nov. 
Male. Length 5.5-6 mm. Black, with the thorax and basal half 
of the abdomen honey-yellow; wings very strongly infuscated, almost 
black. Head large, highly polished, a little more than twice as broad as 
long, not narrowed behind the eyes. Clypeus very small, sharply triang- 
ular, closely punctate, face punctulate; front smooth and highly polished 
with a deep transverse depression above the antennz and below the 
ocelli which occupy a small triangle far from the eyes; antennz long, 
one-half longer than the body; with fifty joints. The fourth very 
distinctly longer than the third. Mandibles fuscous, with black teeth, 
coarsely punctate externally. Palpi very delicate and slender, pale 
yellow. Eyes almost circular, their diameter equalling the length of 
the fourth antennal joint. Mesonotum smooth and polished, with deep 
strongly convergent parapsidal furrows which unite far before the 
~ scutellum. Scutellum strongly convex medially in front, straight on 
its posterior edge, and at the base with a broad deep depression separat- 
ing it from the mesonotum. This groove is divided on the median line 
by a fine carina. Pleurze smooth and shining, the mesopleura deeply 
impressed just below the wing and with a foveate impression just before 
the carina which separates it from the metapleura. Metathorax 
smooth, with a strong median carina that bifurcates behind to form a 
broad triangular petiolar area; also with a lateral, strongly sinuate 
carina that curves laterally to go out beyond the moderately small, 
circular spiracle. Metapleura with a large deep foveate impression 
just anterior to the spiracle and a smaller one below, near the middle, 
just behind the anterior margin. Abdomen broadly sessile, peculiarly 
formed at the base in that the ventral part of the first segment spreads 
out laterally beyond the dorsal part; seen from above it is exposed 
behind on each side to a width of nearly one half the dorsal plate. The 
latter is less than twice as long as broad at the tip which is twice as wide 
as the base; spiracles at the middle, very prominent, their tips as far 
apart as the posterior angles; petiole at base with two short, convergent 
carine. Abdomen smooth and shining, but little widened medially 
and one-half longer than the head and thorax together; black above 
beyond the second segment. Legs slender, loosely hairy; entirely 
black, except for yellowish tips to the trochanters, bases to the tibia 
and a fuscous tinge on the tarsi and anterior tibie. Wings blackened, 
