198 



MEANS OF DEFENCE OF INSECTS. 



pleasant and annoying. Some, however, are less disgusting, 

 particularly Lygceus Hyoscyami, which yields, De Geer found, 

 an agreeable odour of thyme. 1 — Several lepidopterous larvae 

 are defended by their ill smell ; but I shall only particularise 

 the silk-worms, which on that account are said to be un- 

 wholesome. — Phryganea grandis, a kind of May-fly, is a 

 trichopterous insect that offends the nostrils in this way ; but 

 a worse is Chrysopa 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. — Num- 

 berless Hymenoptera act upon the olfactory nerves by their 

 ill or powerful effluvia. One of them, an ant (Formica fcetida 

 De Geer, f ceteris Oliv.), has the same smell with the insect 

 last mentioned. 2 Our common black ant (F. fuliginosd), 

 whose curious nests in trees have been before described to 

 you, is an insect of a powerful and penetrating scent, which 

 it imparts to every thing with which it comes in contact ; and 

 Fabricius distinguishes another (F. analis Latr., f ceteris F.) 

 by an epithet (fcetidissima) which sufficiently declares its 

 properties. Many wild bees (Andrena) are distinguished by 

 their pungent alliaceous smell. Crabro U-flavum, a wasp- 

 like insect, is remarkable for the penetrating and spirituous 

 effluvia of ether that it exhales. 3 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 

 Mesembrina mystacea, a fly 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. 4 And another 

 (Sepsis cynipsea) emits a fragrant odour of beaum. 5 — I have 

 not much to tell you with respect to apterous insects, except 

 that lulus terrestris, a common millepede, leaves a strong and 

 disagreeable scent upon the fingers when handled. 6 Most of 

 the insects I have here enumerated, probably, are defended 

 from some enemy or injury by the strong vapours that exhale 



1 De Geer, iii. 249. 374. 2 De Geer, iii. 611. 



2 Kirby, Mon. Ap. Angl. i. 136. note a. 



4 De Geer, vi. 134. Meigen, Dipt. v. 12. 



o De Geer, vi. 135. 33. 6 ibid. vii. 581. 



