STATES OF INSECTS. (Jmago.) 343 
partially to the other social insects; amongst which, if 
you consult my former communications, there are some 
exceptions to this slothful character in the males’. 
II. Age. There is less diversity in the duration of the 
lives of insects in their perfect than in their larva or pupa 
state. Some, like several species of Ephemere, live only 
a few hours; some never even see the sun”: others, as 
flies, moths, and butterflies, and indeed the majority of 
insects, a few days or weeks; and a comparatively small 
number, such as some of the larger Coleoptera, Ortho- 
ptera, &c., six, nine, twelve, or fifteen months—a period 
beyond which the life of perfect insects rarely extends. 
Some, however, certainly enjoy a longer existence in the 
perfect state. Mr. Baker kept one of the darkling beetles 
(Blaps mortisaga) alive under a glass upwards of three 
years. The rose-beetle (Cetonia aurata), Rosel informs 
us he fed with fruit and moist white bread for as long a 
period *«. Esper kept our most common water-beetle 
(Dytiscus marginalis) in water in a large glass vessel, 
feeding it with meat, for three years and ahalf4, With 
regard to the Arachnida, from the very slow growth of 
Scorpio europaeus, Rosel suspects that it must live two 
or three years; and Audebert is stated to have kept a 
spider for several*. In this respect insects follow a law 
very different from that which obtains amongst verte- 
* See above, Vot. II. 109, 117. > Vor. I. 286. ode. it, G. 
4 Clairville Ent. Helvet. ii. 214—. I have seen it asserted in some 
popular work on Natural History, (the title of which I do not recol- 
lect,) that Mantis religiosa has been known to live ten years; and a 
Jlea, when fed and taken care of,six. But this is so contrary to expe- 
rience in other cases, that the statement seems quite incredible. 
© Rosel HI. 379. N. Dict. d’ Hist. Nat. ii. 285. 
