272 INDIRECT BENEFITS DERIVED FROM INSECTS. 



while writing this letter, tin Elater quite alive and ac- 

 tive, which three or four ants in spite of its struggles 

 were carrying off. An observing friend of mine % who 

 was some time in Antigua, informed me that in that 

 island, a kind of ant which construct their nests in the 

 roofs of houses, when they meet with any animal larger 

 than they can carry olTalive, such as a cockroach, &c., 

 will hold it by the legs so that it cannot move, till some 

 of them get upon it and dispatch it, and then with in- 

 credible labour carry it up to their nest. Madam Me- 

 rian, in her account of the periodical ants mentioned to 

 you before '*, and which is confirmed by Azara*^, notices 

 their clearing the houses of cockroaches and similar ani- 

 mals ; and the Formica omnivora is very useful in Cey- 

 lon in destroying the larger ant, the white ant and the 

 cockroach ''. 



You are not perhaps accustomed to regard wasps and 

 hornets as of any use to us ; but they certainly destroy 

 an infinite number of flies and other annoying insects. 

 The year 1811 was remarkable for the small number of 

 wasps, though many females appeared in the spring, 

 scarcely any neuters being to be seen in the autumn •"; 

 and probably in consequence of this circumstance, flies 

 in many places were so extremely numerous as to be 

 quite a nuisance. Reaumur has observed that in France 

 the butchers are very glad to have wasps attend their 

 stalls, for the sake of their services in driving away the 



^ R. Ki((oo,i;sq. "p. 124 



"= Voyagcx, i. 185. " Percival's Ceylon, 307. 



° Mr. Kiiiglit made the same observation in 1806, and supposes (he 

 scarcity of neuters arose from the want of males to impregnate the fe- 

 males. P/iilos. Trans. \801, p. 243. 



