INDIRECT INJURIES CAUSED BY INSECTS 81 



animal, appearing to be seized with a kind of frenzy, begins to gambol, 

 and run with such swiftness that nothing can stop it. From this sem- 

 blance of temporary madness in oxen when pursued and bored by the 

 OEstrus, the Greeks applied the term to any sudden fit of fury or violent 

 impulse in the human species, calling such ebullition an CEsfrus. The 

 female fly is observed to be very expeditious in oviposition, not more than 

 a few seconds; and while she is performing the operation, the animal 

 attempts to lash her off, as it does other flies, with its tail. The circular 

 hole, made by the augur just described, always continues open, and in- 

 creases in diameter as the larva increases in size; thus enabling it to 

 receive a sufficient supply of air by means of its anal respiratory plates, 

 which are usually near the orifice. But though these insects thus torment 

 and terrify our cattle, they do them no material injury. Indeed, they 

 occasion considerable tumours under the skin, where the bots reside, 

 varying in number from three or four to thirty or forty ; but these seem 

 unattended by any pain, and are so far from being injurious, that they are 

 rather regarded as proofs of the goodness of the animal, since these flies 

 only attack young and healthy subjects. The tanners also prefer those 

 hides that have the greatest number of bot-holes in them, which are always 

 the best and strongest. 1 



The Stomoxys, and several of the other flies before enumerated, as well 

 as the dog and American ticks, are as prejudicial to the ox as to the horse. 

 One species of Hippobosca, I have reason to believe, is appropriated to 

 them ; yet, since a single specimen only has hitherto been taken 2 , little 

 can be said with respect to it. A worse pest than any hitherto enumerated 

 is a minute fly, concerning the genus of which there is some doubt, Fabricius 

 considering it as a Rhagio (R. columbaschensis) and Latreille as a Simu- 

 lium 3 ; but to whatever genus it may belong, it is certainly a most de- 

 structive little creature. In Servia and the Bannat it attacks the cattle 

 in infinite numbers, penetrates, according to Fabricius, their generative 

 organs, but according to other accounts their nose and ears, and by its 

 poisonous bite destroys them in the short space of four or five hours. 

 Much injury was sustained in 1813 from this insect in the palatinate of 

 Arad, in Hungary, and in the Bannat ; in' Banlack not fewer than two 

 hundred horned cattle perishing from its attacks, and in Versetz, five 

 hundred. It appears towards the latter end of April or beginning of May 

 in such indescribable swarms as to resemble clouds, proceeding, as some 

 think, from the region of Mehadia, but according to others from Turkey. 

 Its approach is the signal for universal alarm. The cattle fly from their 

 pastures ; and the herdsman hastens to shut up his cows in the house, or, 

 when at a distance from home, to kindle fires, the smoke of which is 

 found to drive off this terrible assailant. Of this the cattle are sensible, 



1 Much of the information here collected is taken from Reaum. iv. Mem. 12. ; and 

 Clark in Linn. Trans, iii. 289. 



8 The writer of the present letter is possessor of this specimen, which he took on 

 himself in a field where oxen were feeding. 



3 In the Systema Antliatorum (p. 56.) Fabricius most strangely considers this 

 insect as synonymous with Culex reptans L., calling it Scatopse reptans, and dropping 

 his former reference to Pallas, and account of its injurious properties. Meigen (Dipt. 

 i. 294.) makes this insect a Simulia, under the name of <S". maculata. It is repre- 

 sented by Coquebert, whose figure is copied in the translation of Kbllar's work 

 referred to above, and also in the next page. 



Q 



