170 MODERN CLASSIFICATION OF INSECTS. 
In a few instances which have fallen under my observation, the 
pupe are inclosed in a cocoon.* 
I have reared one of the small species of Megaspilus Westw. (Ce- 
raphron Carpenteri Curt.) from Aphides from the bean. And 
Bouché has described another species of Ceraphron (C. Syrphii), the 
larva of which is long and white, with the parts of the mouth brown, 
and which infests the pupz of Syrphus Ribesii and balteatus. 
(Naturg. d. Ins. p. 175.) 
The species of Platygaster are serviceable in checking the over- 
production of some of the minute Tipulideous insects which infest the 
cerealeous plants, such as Cecidomyia. Mr. Kirby (Linn. Trans. 
vol.iv. and v.), has detailed the habits of two species of this genus, 
Pl. Tipule, which is found on the glumes of the wheat in July, where 
it deposits its eggs in the larvae of the Cecidomyia Tritici; and Pl. 
inserens, which is found in June depositing its eggs in the valvules of 
the corolla of the wheat, the larvae, when hatched, probably attaching 
themselves to the larvee of the same insect. Pl. phragmitis Schrank 
inhabits the panicles of Arundo phragmitis, evidently with a similar 
object. I have reared two species of Platygaster, which are parasitic 
upon the gall-making Cecidomyia of willows, and observed that their 
cocoons, which are very thin and membranous, are attached together 
in a mass, and covered by the thin skin of their victim, the segments 
of which are slightly visible across the surface (jig. 78. 14.); and 
Bouché has described a Diapria, which is parasitic on the larve of 
Cec. Artemisiz (D. Cecidomyiarum ). 
The Canon Schmidberger has published a very detailed account of 
the habits of Inostemma Boscii, under the name of Die paradoxe 
Birn-Wespe, in Kollar’s work upon obnoxious insects ( Verhandl. Land- 
wirthsch.- Gesellsch. in Wien, vol. v. 1837), asserting that it feeds upon 
the young fruit of the pear, and is certainly not parasitical, although 
he had observed the transformations of one of these gall midges in 
* De Geer has figured a minute black species with dirty white legs, which he 
reared from minute cocoons attached together side by side, found in the burrow of the 
larva of one of the pear-leaf miners. The figure has somewhat the air of an 
Encyrtus; but the pup are naked in that genus. Can it be a Platygaster? or is 
it one of the Eulophides, as the antenna seem to imply? (Mém. tom. i. pl. 30. 
fig. 1417.) He has also figured on the same plate another minute black species 
with a large black stigma, which infests the larve of rose-leaf miners. The an- 
tenn are described as very long and multiarticulate, which would prevent this from 
being a Megaspilus, although the size of the abdomen is too large for a Microgaster 
(pl. 30. fig. 21.). 
