Jan., '07] ENTOMOLOGICAL NEWS. 9 



his back it takes him half an hour before he makes a motion 

 to get on his feet. 



So far as I can find out, he has no likes or dislikes to make 

 him an easy capture, there is no particular place he prefers to 

 stay, he don't belong to any club, he don't play golf or other 

 games. Clubbing a tree for him won't do much good, as he 

 grits his teeth and stays there, nine times out of ten. I con- 

 clude that he will not be exterminated by collectors, and be- 

 fore all the latter are supplied with a good series, some method 

 of propagation must be invented. 



Some recent work on the development of Hymenop- 



terous Parasites. 



By Dr. Wm. A. Riley. 



In the Entomological Xews for September, 1905, I called 

 attention to the discovery, by Marchal, of a new type of de- 

 velopment, occurring in certain parasitic Hymenoptera. In 

 studying the development of Agcniaspis fusicollis and of Poly- 

 gnotus mimitus, Marchal* found that a single egg, in the 

 morula stage, would spontaneously break up and give rise to 

 many distinct individuals. I referred to the observations of 

 Pergande and of Giard, who found nearly three thousand 

 individuals of Litomasiix truncatcllus in a single larva of 

 Plusia gamma, and to Giard's prediction that here, too, would 

 be found a case of polyembryony. 



There has come to hand a paper by Filippo Silvestrit who 

 has studied the life history of this parasite and brought to light 

 many interesting and striking facts. 



♦Marchal, P. 1904. Recherches sur la biologie et la developpemcnt 

 defl Hymenopteres parasites. 1. La polyembryonie specifique ou ger- 

 minogonie. Arch. zool. exp. (4) ii. PP257-335. pis. ix-xiii. 



fSilvestri, F. 1906. Contribuzione alia conoscenza biologica degli 

 imenotteri parassiti. 1. Biologia del Litomastix truncatellus. From 

 Ann. Scuol. Agric. Portici.. vi. 51 pp., 5 pi. and 13 text figs. This paper 

 is a second preliminary note. The first, which summarizes the es- 

 sential features of Silvestri's work, but is not illustrated, appeared Nov. 

 10, 1905, in the Rendic. R. Acad. Lined ser. 5, vol. xiv. pp. 534-54-'. 



