affecting the Corn- Crops. 
497 
basal segments very much narrowed, rugose, and brown, the others 
forming an elongate-ovate body; ovipositor scarcely visible ; wings 
rather long, transparent, and iridescent ; superior ample, with one 
marginal, two sub-marginal, and two discoidal cells; stigma 
elongate-ovate, and brown, as well as the nervures; inferior wings 
much smaller, the nervures dark and distinct ; legs very slender, 
hinder the longest, anterior ochreous; tarsi fuscous; hinder tro- 
chanters and thighs with an ochreous ring at their union : length 
2^ lines ; expanse 3f. (Fig. 36, magnified). 
All the species of this parasite, of which there are twelve de- 
scribed in the ' British Entomology,' inhabit moist meadows, and 
are principally found from the end of June to September, which is 
strong evidence that many of the Chlorops are bred from the stems 
of grasses. 
Another parasite I bred also from the same stems of wheat and 
barley, which is an exquisitely beautiful little creature in form and 
colour. This had been likewise described by Olivier,* and M. 
Gueriu found some specimens in the bottle containing the corn 
which produced the Chlorops Herpinii and the above Ccclinius. 
On the 11th of last August, and again on the 20th, I found a male 
of this Pteromalus, which had been bred from a stem of the gouty 
barley from Sarsden ; and I soon discovered a little hole, about 
three-quarters of an inch from the base, through which it had 
emerged (tig. 25, d). At the base of another abortive ear within 
the spathe, I found a second specimen of the Pteromalus dead, and 
not a vestige of a pupa-case, showing that this parasite is veiy dif- 
ferent in its economy to the Ccelinius, and lays its eggs in the 
maggots of the Chlorops at such an early period that they are de- 
voured before they have time to change to pupae, so that there was 
nothing remaining in the cavity of the stem but the excrement of 
the Chlorops' maggot. It is however the opinion of some naturalists 
that this family of insects destroys the true parasites by puncturing 
their pupae. 
In a former Essay I described and figured a little fly which was 
parasitic in the pupa) of the "White-cabbage butterfiv." j The 
parasite of the Chloi-ops is closely allied to it, consequently it is 
of the same Order Hymenoptera, the Family CYNiPiDiE or 
Chalchhd^, and the Genus Pteromalus, of which my genus 
Colax forms a section. | It was named, apparently by Olivier, 
Chalcis micans ; and is closely allied to, if it be not identical with, 
Mr. F. Walker's Pteromalus Pione. § 
15. P. micans, the glittering Pteromalus (fig. 37). — Head and 
* Oliv., Mem. Soc. d'Agr., vol. xvi. p. 477, pi. 3,f. 12. 
t Royal Agiic. Jour., vol. iii. pi. E. f. 13. 
t Vide Curtis's Brit. Ent., fol. IGG. 
§ Monographia Chalciditum, p. 224, No. 21. 
