November 1S97.] 



psrcHE. 



137 



Head transverse, wider than the thorax, 

 concave behind, about three times as wide as 

 thick antero-posteriorlv, the space between 

 tlie eves about twice as wide as the eve or a 

 little more than twice the widtli of tlie eye; 

 viewed from in front subtriangular; ocelli 

 reddish, subtriangularly arranged. Antennae 

 inserted on the middle of the face, 13-jointed. 

 with 2 ring-joints, the scape extending to 

 middle ocellus or half as long as the flagel- 

 lum without the pedicel, the latter obconical, 

 smooth, shorter than the first flagellar joint ; 

 flagellum subclavate or gradually incrassated 

 towards tip, clothed with a short rather dense 

 pubescence, the joints delicately fluted, the 

 first joint the longest, less than twice as long 

 as thick, the second a little shorter, the fol- 

 lowing gradually and imperceptibly sliorten- 

 ing so that the last joint is scarcely as long 

 as wide. 



Thorax a little more than three times as 

 long as wide at the widest part of the prono- 

 tum, rounded anteriorly and with its upper 

 surface narrowed at the middle, the niesono- 

 tum as long as wide posteriorly, slightly 

 narrowed anteriorly, with the parapsidal fur- 

 rows only indicated anteriorly; axillae as 

 wide from each other as their width at base, 

 tlie scutellum proper convex, longer than 

 wide; metathorax not short, with a distinct 

 median carina, the lateral folds wanting, or 

 at least only indicated by foveae at base, the 

 spiracles not large, rounded, with ratlier 

 broad sulci behind. Front wings with the 

 nervures pale, the marginal nervure one and 

 a half times as long as the stigmal, or a little 

 longer, the stigmal two-thirds as long as the 

 postmarginal, subclavate, the postmarginal 

 a little shorter than the marginal. Abdomen 

 conic-ovate, as long as the thorax, the second 

 segment the longest, as long as segments 3-5 

 united, with a large fovea at base above 

 where it unites with the short petiole, and 

 with its posterior margin squarely truncate, 

 segments 3-6, subequal, the 7th longer than 

 the foregoing, the 8th conic. 



$■ Coeruleous; tibiae except at both ends 



embi'owned, the scape yellowish beneath, 

 the flagellum long, filiform, with black pile, 

 all the joints long, cylindrical, the first the 

 longest, as long as the scape, or about 7 times 

 as long as thick, 'the following very gradually 

 shortening; abdomen oblong, nearly linear, 

 with a large oblong, yellow spot on basal 

 third above; otherwise as in female. 



This ■ species was bred by Dr. 

 Marchal, itr June, 1S95, from Cecido- 

 myia destructor Say attacking stems 

 of wheat. 



The species coines evidently nearest 

 to H. torymoides Thomson, but is 

 readily separated in the 9 by color, 

 the shorter abdomen, relative length of 

 the segments and by the length of the 

 flagellar joints, while the $ is at once 

 distinguished by the very long joints of 

 the flagellum which are clothed with 

 black pile, not white pile as in H. 

 torymoides. 



( s) Eitpcliitits atropiirpiireiis 



Dalm. g 9 . 



(6) Polygiiotus {Platygaster) zos- 

 Ine Walk. $ . 



With the above parasites I found also 

 a single male specimen of Isosoma 

 brcvicorne Walk. 



Dr. Marchal also reports Oscim's 

 pusillus as occurring in the oat stubble. 



Host. 



Cecidomyia avenae 



Marchal. 



( 1 ) Boeotomns coxalis Ashm. $ . 



(2) Merisus destructor Say $ 9 • 



(3) Homoporiis lunigerm^e.^ $ 9- 



(4) Etipelmus atropurpuretis Dalm. 

 ( = a/rocoerz^/ez^j Thoms.) ^ 9- 



(5) Eupehnus degeeri Dalm. 9 ■ 



