NATURAL ENEMIES. 29 
Tn England, Miss Eleanor A. Ormerod and Mr. Fred Knock have 
obtained the following parasites: 
Chalcidid e. 
McrisiiH destructor Say. 
Bceotomua subapterua I 'i ley. 
Aferi8U8 intermedins Lindm. 
Entedon epigonua Walk. 
Eupelmu8 karachii Lindm. 
Eury8capu8 saltator Lindm. 
Tetrastichua rileyi Liudm. 
Tetrastichus (2 species). 
Proctotrypid^e. 
Pohjynotus minimis Lindm. 
Platygaster herrickii Packard. 
Marchal records from Cecidomyia destructor the following as being 
obtained from Vendee: 
Chalcidldae. 
Mersus destructor Say. 
HoIcwm cecidomyia' Ashmead. 
Baotomus riifomaeidatus Walk. 
Eupelmus atropnrpureus Dalm. 
Proctotrypidae. 
Polygnotus minutus Lindm. 
Polygnotus zosini Walk. 
Trichasis remulits Walk. 
Before taking up in detail the species of parasites known to infest 
the insect in America, we may stop to notice the remarkable studies of 
Marclial upon the early development of some of the parasites as observed 
by him. The most striking of these relate to the early stages of Tricha- 
sis remulus, which is said to deposit its eggs in May and June, either 
in the egg or the very young larva of the Cecidomyia, the larva' of the 
Platygaster being always encountered in the very young larva of the 
Ceeidomyia. In some cases where the punctures by the parasite have 
been too numerous the larvae attacked die and dry up without com- 
pleting their development. In such cases the parasites are arrested in 
their development and perish. More often the Oecidomyian larva con- 
tinues to feed and grow to the time of forming the puparium. The 
puparia of the attacked larva 1 are smaller and paler than those of nor- 
mal larva', sometimes even of minute size, generally very flat, and 
always of irregular form. 
The course of development of the Trichasis has been very fully sum- 
marized by Howard* in his review of Marehal's paper, and 1 can do no 
better than reproduce the following extract: 
According to Marchal the first larval form of T.reinxlus corresponds to the type of 
the curious oy clops-like larvae studied by GaniD, and which certain authors regard 
as an adaptive form, while others sec in it an ancestral form. The post-embryonic 
development, according to Marchal, is as follows: 
When they are young and motionless and have not issued from the cysts which 
(Science Vs.. Vol. VII, pp. 246-247.) 
