On the Bionomics and Development of Lygo- 
cerus testaceimanus, Kieffer, and 
Lygocerus cameroni, Kieffer (Procto- 
try poidea-Ceraphronidae), parasites of A phi- 
dius (Braconidae). 
By 
Maud D. Haviland, 
Fellow of Newnham College, Cambridge. 
With 18 Text-figures. 
INTRODUCTION. 
THE Proctotrypoidea have been less studied than most other 
sroups of the Hymenoptera Parasitica. Ganin(1869) was the first 
to study the embryology of certam members of the group (8). 
In 1884, Ayers (2) described the development of the Scelionid, 
Teleas. In 1898, Kulagin (14) resumed the study of Plat y- 
gaster; and in 1906, Marchal (18) published the results of 
his elaborate researches into the embryology and development 
of that family. In recent years much work has been done on 
this group from the systematic standpoint, notably in the 
monographs of Ashmead (1) in America, and of Kieffer (18) in 
Europe, but the life-histories of most of the families are com- 
paratively little known. 
The following is an account of the bionomics and _post- 
embryonic development of two species of the genus Lygocerus, 
of the sub-family Ceraphroninae. These forms are parasites of 
the larvae and pupae of certain Braconidae, of the family 
Aphidiidae, which are themseives internal parasites of various 
plant-lice.* | 
I would here express my sincere thanks to Professor Stanley 
1 A preliminary note on these observations by the writer appeared in 
the * Proceedings of the Cambridge Philosophical Society’, 1920, vol. xix, 
EPevil. 
