CHALCIDIDiE. 



203 



parasites on other Ichneumon parasites, as there are species 

 preying on the genus Aphidius, wliich is a parasite on tlie 

 Aphis. Mr. Walsh has bred a species of Hocliieria and of 

 Gtyphe, which are parasitic on a Microgaster, which in turn 

 preys upon tlie Army-worm, Leucania unipuncta ; and Chalcis 

 albifrons Walsh, was bred from the cocoons of Pezomachus, an 

 Ichneumon parasite of the same caterpillar. 



The pupjE of some species are said to have the limbs and 

 wings soldered together as in Lepidoptera, and the larvae sel- 

 dom spin a silken compact cocoon. We have 

 probably in this country at least a thousand 

 species of these small parasites, nearly twelve 

 hundred having been named and described in 

 Europe alone. They are generally large enough 

 to be. pinned or stuck upon cards or mica ; some 

 individuals should be preserved in this way, 

 others, as wet specimens. Fig. 136. 



Chalcis is known by the abdomen having a long pedicel, its 

 much thickened, oval thighs, and curved tibiae. Chalcis. bra- 

 cata (Fig. 136), so named by Mr. Sanborn "in allusion to the 

 ornamental and trousered appearance of the posterior feet" 

 is about .32 inch in length. "Reaumur has described and 

 figured a species of Chalcis, which is parasitic in the nest of 

 the American wasp Epipone nitidulans and which he regarded 

 as the female of that wasp." (Westwood.) 



The genus Leucospis is of large size. It is known by having 

 the large ovipositor laid upon the upper surface of the abdo- 

 men, and being spotted and banded with 

 yellow, resembling wasps. One of our more 

 common species is the L. affinis (Fig. 137) of 

 Say. The Cuban i. Poeyi Guerin is para- 

 sitic on the Megachile Poeyi of Guerin. 



The well-known Joint-worm, Eurytoma^ 

 is thought by many to produce galls on 

 wheat-stems. The antennae are, in the male, slender and pro- 

 vided with verticils of hairs. The acutely oval abdomen has 

 a -short pedicel. The hind legs are scarcely thicker than the 

 fore limbs. E. horclei Harris (Fig. 138) is found in gall-like 

 swellings of wheat-stalks. It is still a matter of discussion, 



Fig. 137. 



