339 
Parasite of Acronycta anceedina, the Horse chestnut 
defoliator. 
OPHION AUREOLATUS, Cameron, 
Plate XX, figs. 1, 1a, 10. 
Classification :—Order, HYMENOPTERA. Family, Ichneumonide. 
Parasitic upon the larve of Acronycta anxdina, (See 
No. 1, p. 91.) 
Description. 
Cocoon.—The yrub spins a cocoon consisting of a yellow 
matted silk felt in which it pupates. This cocoon is spun 
inside the lepidopterous pupaand is shown in Plate XX, fig. 1, 
Fig. 1a shows the lepidopterous pupa with a fly emerging. 
Imago.—A moderately large bright yellow fly with two pairs 
of large membranous wings with well-marked veins in them, the 
upper ones considerably larger than the lower. Antenne and 
legs long and slender. The abdomen is joined to the thorax by 
a very slender peduncle, the body swelling out and thickening 
considerably in the vertical plane behind this. The segments 
comprising this thickened portion are curved abruptly and 
vertically downwards. Horizontal length, ~ inch. Length 
taken round curve of dorsal surface of abdomen, 1 inch. Plate 
XX, fig. 14, shows this insect. 
Life-Fitstory. 
The life-history of this ichneumon probably corresponds, as 
far as dates of appearance go, to that of its host Acronycta anze 
dina, the larvze of which moth seriously defoliate the horse 
chestnut in Jaunsar. The caterpillars were excessively numer- 
ous in the years 1899 and 1goo, and inthe latter year large 
numbers of them were parasitised by this ichneumon, I found 
very few larve on the trees in 1got, their numbers having 
been practically decimated for the time being by the parasite. 
Mr. B. B. Osmaston collected a large number of cocoons of 
A. anzdina in August 1900 and made them over to me 
at Chittagong in December of that year. I took them to Dehra 
Dun and bred out flies in February 1901, the dates of issuing 
