MEANS OF DEFENCE OF INSECTS. 243 
agreeable odour of thyme*.—Several lepidopterous larvae 
are defended by their ill smell; but I shall only particu- 
larize the silk-worms, which on that account are said to 
be unwholesome.—Phryganea grandis, a kind of May fly, 
is a trichopierous insect that offends the nostrils in this 
way; but a worse is Hemerobius Perla, a golden-eyed 
and lace-winged fly, of the next order, whose beauty is 
counterbalanced by a strong scent of human ordure that 
proceeds from it.—Numberless Hymenoptera act upon the 
olfactory nerves by their ill or powerful effluvia. One of 
them, an ant (Lormica fetida De Geer, fatens Oliv.), has 
the same smell with the insect last mentioned. Our 
common black ant (£. fuliginosa, Latr.), whose curious 
nests in trees have been before described to you‘, is an 
insect of a powerful and penetrating scent, which it im- 
parts to every thing with which it comes in contact; and 
Fabricius distinguishes another (Ff. analis, Latr., fetens, 
F.) by an epithet (_fcetidissima) which sufficiently declares 
its properties. Many wild bees (Melitta K., Andrena F.) 
are distinguished by their pungent alliaceous smell. Crabro 
U. flavum, Helw., a wasp-like insect, is remarkable for 
the penetrating and spirituous effluvia of ether that it ex- 
hales4. Indeed there is scarcely any species in this order 
that has not a peculiar scent.—Some dipterous insects— 
though these in general neither offend nor delight us by 
it—are distinguished by their smell. Thus Musca mys- 
tacea, L., afly that in its grub state lives in cow-dung, 
savours in this respect, when a denizen of the air, of the 
substance in which it first drew breath. And another 
* De Geer, iii. 249. 374. » Tbid. 611. ¢ Vot, I. 4th Ed. 483. 
4 Kirby, Mon. Ap. Angl. 1. 136. note a. 
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