MEANS OF DEFENCE OF INSECTS. 423 
The caterpillar of the moth of the beach (Stauropus Fagi), called the 
lobster, is distinguished by the uncommon length of its anterior legs. Mr. 
Stephens, an acute entomologist, relates to me that he once saw this 
animal use them to rid itself of a mite that incommoded it. They are pro- 
bably equally useful in delivering it from the ichneumon and its other insect 
enemies. Dr. Arnold has made a curious observation (confirmed by Dr. 
Forsstrém with respect to others of the genus) on the use of the long pro- 
cesses or tails that distinguish the secondary wings of Thecla Jarbas. 
These processes, he remarks, resemble antennz, and when the butterfly is 
sitting it keeps them in constant motion ; so that at first sight it appears to 
have a head at each extremity ; which deception is much increased by a 
spot resembling an eye at the base of the processes. These insects, per- 
haps, thus perplex or alarm their assailants. — Goedart pretended that the 
anal horn with which the caterpillars of so many hawk-moths (Sphingide) 
are armed, answers the end of a sting, instilling a dangerous venom: but 
the observations of modern entomologists have proved that this is altogether 
fabulous, since the animal has not the power of moying them. Their use 
is still unknown. 
Whether the long and often threatening horns on the head, the thorax, 
and even elytra, with which many insects are armed, are beneficial to 
them in the view under consideration, is very uncertain. They are fre- 
quently sexual distinctions, and have a reference probably rather to 
sexual purposes and the economy of the animal, than to anything else. 
They may, however, in some instances deter enemies from attackin 
them; and therefore it was right not to omit them wholly, though I shal 
not further enlarge upon them. Their mandibles or upper jaws, though 
principally intended for mastication, —and in the case of the Hymenoptera, 
as instruments for various economical and mechanical uses, — are often 
employed to annoy their enemies or assailants. I once suffered consider- 
able pain from the bite of the common water-beetle (Dytiscus marginalis), 
as well as from that of the great rove-beetle (Goerius olens); but the most 
tremendous and effectual weapon with which insects are armed — though 
this, except in the case of the scorpion, is also a sexual instrument, and 
useful to the females in oviposition —is their sting. With this they keep 
not only the larger animals, but even man himself, in awe and at a distance. 
But on these I enlarged sufficiently in a former letter.” 
__ These weapons, fearful as they are, would be of but little use to insects 
if they had not courage to employ them: in this quality, however, they 
are by no means deficient ; for, their diminutive size considered, they are, 
many of them, the most valiant animals in nature. The giant bulk of an 
elephant would not deter a hornet, a bee, or even an ant, from attacking 
it, if it was provoked. I once observed a small spider walking in my 
path. On putting my stick to it, it immediately turned round as if to 
defend itself. On the approach of my finger, it lifted itself up and stretched 
1 De Geer, i. 149. 
* Mr. MacLeay relates to me, from the communications of Mr. E. Forster, the 
following particulars respecting the history of Mutilla coccinea, which from this 
Account appears to be one of the most redoubtable of stinging insects. ‘The females 
are most plentiful in Maryland in the months of July and August, but are never 
Very numerous. They are very active, and have been observed to take flies by 
Surprise, A person stung by one of them lost his senses in five minutes, and was 
So ill for several days that his life was despaired of. 
ER 4 
