196 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



PARASITES ON THE CLOVER-SEED MIDGE. ' 



The first of these parasites belongs to the same subfamily (EurytomlSae) 

 of the Chalcididae as does the celebrated joint worm fly {Isosoma kordei). 

 It was placed in Mr. Howard's hands, and by him determined to be a 

 new species of the genus Eurytoma. He submits the following : 



Generic characters. — Insects of small size and compact form. Head of moderate 

 size ; antennae with females short and nearly naked; of 10 or 11 joints; with males 

 longer and with whorls of hair. Collar very prominent and nearly quadrate. Top of 

 head and thorax strongly punctured. Abdomen smooth and shining; with the $ 

 slightly compressed laterally, and of an irregular oval shape, scarcely pedunculate, 

 very sharjJ at tip; with the ^ rounder, smaller, and with a stout and quite long pe- 

 duncle. Legs rather slender ; middle and hind tibiae with small spines at tip ; huid 

 tibiae without rows of bristles. Subcostal vein strong, and reaching the costa at or 

 slightly before the middle of the wing, continues for a very short distance or not at 

 all along costa before giving off stigma, which is straight, short, and somewhat clubbed 

 at the tip, usually with slight indications of a short branch. 



Eurytoma FUNEBRis n. sp. Male. — Length of body, 1.7'""'., expanse of wings, 2..5™™. 

 Head slightly wider than thorax ; antennae nearly as long as thorax ; flagellum of an- 

 tennae 6-jointed (counting the club as 1 joint) ; joints very strongly incised from above, 

 subeqiial in length except club and first joint ; each joint, except club, with two whorls 

 of yellowish hair, each whorl as long as the joint. Top of head and thorax coarsely 

 punctured, and covered with sparse and very short whitish hair. Subcostal vein yel- 

 lowish and strong, reaches eosta a little before the middle of the wing, and almost im- 

 mediately gives oif stigma ; stigma with a small club and faint indication of a branch. 

 Peduncle very strong and not long ; abdomen very small, less than half the length of 

 the thorax. General color black, eyes dark brown, knees, anterior tibiae, all tarsi 

 light brown. 7 specimens. Female. — Length of body, 1.9 """>., expanse of wings, 2.7 """. 

 Antennae shorter than in $, and joints much more closely united; no hairs; flagellum 

 7-jointed, the club larger in proportion than in the $ . Abdomen longer than thorax, 

 not pedunculated; ovipositor slightly extruded, light brown in color; 8 specimens. 



This species comes very near to tlie European E. gihia, Boh., but we deem it alto- 

 gether likely that it will stand as a distinct species. 



Parasitic upon the clover-seed midge {Ceddomijia legvmenicola Lintuer); working 

 upon the larva while in the clover-seed capsule, undergoing all of ics transformations 

 within the seed vessel, and making its exit as an adult through a round hole cut in 

 the side. May and June, D. C. 



The first specimens of this parasite were found upon the 3d of May, 

 and from that date until the end of June they were ^ery abundant. As 

 stated above, they undergo their transformations within the seed, and 

 as flies gnaw an irregular hole through the seed vessel just large enough 

 to let them out at or shortly after the time when the maggots have left 

 the seed to go into the ground. The examination of many seed heads 

 on the 20 th of June showed the fact that, on an average, five-sixths of 

 the seed had been destroyed by the midges, and that four-fifths of the 

 midges had been destroyed by this parasite. .Hence by tbe good ofllces 

 of this one species of Chalcid the prospective numbers of the next brood 

 were reduced 80 per cent. The funereal Euiytoma, as it may be called, 

 was bred only from the Washington specimens. 



The ]ynsTAKEN parasite {Platygaster error Fitch), — The second par- 

 asite was bred from specimens of the clover-midge, received from Mr. 

 G. C. Snow, of Branchport, Yates County, Xew York. Instead of un- 

 dergoing its transformations entirely within the seed, this parasite de,- 

 velops so slowly that the midge larva has time to leave the clover head, 

 go into the ground, and spin its cocoon before its operations are stopped. 

 The full-gTOwn parasite emerges from the cocoon of its host. 



This parasite belongs to the family Proctotriipidae and seems to be a 

 species described by Fitch as Platygaster error. Tlie specimens descri bed 

 by Dr. Fitch were found in wheat-fields; and he concluded, upon what 

 seem to be very insufficient data, that the insect was an egg x>arasite 



