MEANS OF DEFENCE OF INSECTS. 243 



(Blatta orientalis, L.)? belonging* to the Orthopiera or- 

 der, is not remarkable for a pleasant scent ; — but none 

 are more notorious for their bad character in this re- 

 spect than the bug tribe (Ciinicidce), which almost uni- 

 versally exhale an odour that mixes with the scent of 

 cucumbers another extremely unpleasant and annoy- 

 ing. Some however are less disgusting, particularly 

 ■Lf/gceus Hyoscyami^ F., which yields, De Geer found, 

 an agreeable odour of thyme ^. — Several lepidopterous 

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

 particularize ^\q silk-worms, which on that account are 

 said to be unwholesome. — Phryganea grandis, a kind 

 of May-fly, is a trichopterous insect that offends the 

 nostrils in this way ; but a worse is Hemerohius Perla, 

 a golden-eyed and lace-winged fly, of the next order, 

 w hose beauty is counterbalanced by a strong scent of hu- 

 man ordure that proceeds from it. — Numberless Hy- 

 Ttie^ioptera act upon the olfactory nerves by their ill or 

 powerful effluvia. One of them, an ant {Formica foetida, 

 De Geer, fcetens^ Oliv.), has the same smell with the 

 insect last mentioned''. Our common black ant (F. fuli- 

 ginosa, Latr.), 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. atialis, Latr., foetcns, F.) by an epithet 

 ( fcctidisshna) which sufficiently declares its properties. 

 Many wild bees {Melitta, K., Andrena, F.) are distin- 

 guished by their pungent alliaceous smell. Crabro 

 U.Jlavuin, Helw., a wasp-like insect, is remarkable for 

 the penetrating and spirituous effluvia of ether that it 



" De Geer, iii. 249. 374. " Ibid. 61 1 . " Vol. I. ?d Ed. 48S. 

 B. 2 



