234- DISEASES OF INSECTS. 



large beetles, where do they take their principal growth ? 

 It cannot be as parasites on the little bees or flies that 

 they are usually found upon ; they must soon desert 

 them, and like their kindred blister-beetles, as is most 

 probable, have recourse to vegetable food. What an 

 anomaly in rerum natura ! It is much to be wished that 

 some skilful insect-anatomist would carefully dissect the 

 Meloe ; or perhaps by digging round the roots of the 

 ranunculuses and other acrid plants the larva of that 

 beetle might be discovered in a later stage of growth, 

 and so this mystery be cleared up. I should observe 

 here, that Scopoli has described three parasites as Pedi- 

 culi ; viz. P. rostratus, coccineus, and Cerambycinus ; the 

 first of which Fabricius has adopted under the name of 

 P. Gryllotalptf, but which are all evidently hexapod 

 Acarina*. 



Acariasis seems a disease almost as universal amongst 

 insects as Scolechiasis ; with this difference however, that 

 Acari most commonly take their station upon them in 

 their perfect state. You have doubtless often observed 

 the common dung-beetles (Geotrupes) covered on the 

 underside of their body with small mites (Gamasus 

 Coleoptratorum) which look as if they were engaged 

 in suction they are often so numerous that no part is 

 uncovered; they also attack other beetles 5 , and are some- 

 times found on humble-bees. They are easily disturbed, 

 run with great swiftness, and may often be seen in hot- 

 beds and fermenting dung prowling in search of the 

 stercorarious beetles. But the most remarkable insect 

 of this kind is the Uropoda vcgetajis : it derives its nu- 

 triment from the insects it assails not by its mouth, but 

 3 Ent. Cam, 10524. b Hister particularly. 



