178 "Journal of the Asiatic Society of Bengal. [May, 1906, 
specimens, but always much smaller than with the female, The 
insect, as a whole, appears distinctly smaller than the female. 
It will be seen that there is absolutely no difficulty even at 
first sight in distinguishing the sexes. The points which settle 
the sex to a casual observer, are :— 
1. The size of the orange spot on the pronotum and scutel- 
lum. Inthe female it is much bigger than in the male, and 
in fact in the latter it is often hardly to be seen. 
2, The shape of the abdomen, which is always larger and 
stouter in the female. 
3. The size of the insect, the female being always distinctly 
bigger in every respect. 
4, T 
samples could not be made by myself personally, but the ease of 
distinction prevents the possibility of any material error, and 
are about equally diffic 
that no material error is introduced on this account. They are 
away. ; 
nif - ‘ . F , 
The only error which may seriously affect the figures, is the 
fact that the numbers were, on the who . 
years, owing to the measures taken against the insect. It 18 
a factor which might influence the relative numbers of the sexes, 
in a manner of which we know nothin 
exceedingly numerous, while in December the number usually, 
ace not always, rapidly drops. I give a special table of rai 
all each month at Behalli, in order that its distribution relative 
to ae may be ascertained. ‘ 
gigas eee years are taken together, the figures seem 10. 
~ 
Sg amie IND Se Gast eee Thee pan ee A of ee ee ee a, 
SS a Sa Se AE ee ees ie com ea tien emer ore en ae TRU ele sa - 
