Chap. VIII 



Proportion of the Sexes. 



253 



from eggs or caterpillars, I have received only the few following 



cases : — ■ 



The Rev. J. Hellius 83 of Exeter reared, during 1868. V 



imagos of 73 species, which consisted of. . . y 

 Mr. Albert Jones of Eltham reared, during 1868,1 ; 



imagos of 9 species, which consisted of . . . y 

 During 1869 he reared imagos from 4 species, con-l| 



sisting of y 



Mr. Buckler of Emsworth, Hants, during 1 869,\ I 



reared imagos from 74 species, consisting of. . \\ 

 Dr. Wallace of Colchester reared from one brood of 1 1 



Bombyx cynthia y 



Dr. Wallace raised, from cocoons of Bombyx Pernyill 



sent from China, during 1869 /j 



Dr. Wallace raised, during 1868 and 1869, from twoij 



lots of cocoons of Bombyx yama-mai . . ,/i 



Total ... . 



Males. 



Females. 



934 



761 



So that in these eight lots of cocoons and eggs, males were produced 

 in excess. Taken together the proportion of males is as 122 "7 

 to 100 females. But the numbers are hardly large enough to be 

 trustworthy. 



On the whole, from these various sources of evidence, all pointing 

 in the same direction, I infer that with most species of Lepidoptera, 

 the mature males generally exceed the females in number, whatever 

 the proportions may be at their first emergence from the egg. 



With reference to the other Orders of insects, I have been able 

 to collect very little reliable information. With the stag-bee! le 

 (Lucanus cervus) "the male3 appear to be much more numerous 

 " than the females ;" but when, as Cornelius remarked during 1867, 

 an unusual number of these beetles appeared in one part of Germany, 

 the females appeared to exceed the males as six to one. With one of 

 the Elateridse, the males are said to be much more numerous than the 

 females, and " two or thiee are often found united with one female ; 84 

 " so that here polyandry seems to prevail." With Siagonium (Staphy- 

 linidoe), in which the males are furnished with horns, " the females are 

 u far more numerous than the opposite sex." Mr. Janson stated at the 

 Entomological Society that the females of the bark- feeding Tomicus 

 villosus are so common as to be a plague, whilst the males are so rare 

 ris to be hardly known. 



83 This naturalist has been so 

 kind as to send me some results 

 from former years, in which the 

 females seemed to preponderate ; 

 Vut so many of the figures were 

 estimates, that I fcuad it impossible 

 to tabulate them. 



84 Giinther's * Record of Zoo- 

 logical Literature,' 1867, p. 260. 

 On the excess of female Lucanus, 

 ibid. p. 250. On the males of Luca- 

 nus in England, Westwood, ' Modern 

 Class, of Insects,' vol. i. p. 187. On 

 the Siageniurn, ibid. p. 172. 



