PARASITES OF THE TETTIGID^E. 39 



and he has given excellent drawings, including the 

 mouth organs of the larvae.* 



Mr. Albert Michael, the accomplished author of the 

 * British OribatidaB,' remarks that the Trombiid^ are 

 strictly predatory in the adult stage, but that they 

 have larvae which — although not truly parasitic any 

 more than the gnat or leech — will yet attach them- 

 selves to the bodies of insects, or even of mammals, 

 and are usually separated from their hosts only by 

 death or by artificial means. These pests, burrowing 

 into the skins of warm-blooded animals, cause intense 

 irritation, and in hot countries they sometimes set up 

 dangerous inflammation. The harvest bug, or rouget 

 of the French, is here a familiar example.! 



The Oribatidae, or, as they are sometimes called, the 

 *' eyeless beetle mites " (although they do not attack 

 beetles), are in no ways predatory like the Trombiidae. 



It is not always the same species which causes such 

 intolerable itching on our legs after walking on the 

 long grass in autumn ; but the chief offender is the 

 larva of Trombidium Jiolosericeum. It must not be 

 supposed that one species of Tromhidium is parasitic 

 solely on one species even of insects. On the contrary, 

 the larvae of several species of Tromhidium may be 

 found parasitic on the same insect, and the larvae of 

 one species of Tromhidium may be seen to attack 

 several insect hosts. " In fact, they may get on to 

 almost any living creature which they can obtain, and 

 which is large enough to carry them about; but doubt- 

 less certain animals — such, for instance, as the little 

 crustacean Phalangidae, or so-called long-legged harvest 

 spiders — are more infested than other small animals." 



The adult Tromhidia are free living; and can exist 

 away from any host, but they certainly attach them- 

 selves to some kind of host if they have any chance 

 of so doing. 



* " Memoire sur les Metamorphoses des Acaiiens et sur celles des 

 Trombidions," An. Sc. Nat. 6 ser. Zool. t. 4, 1876. 

 t See " Oribatidae," Eay See. 1883, vol. i. p. 5. 



