INDIRECT BENEFITS DERIVED FROM INSECTS. 157 
m France by the name of Vinaigrier, is s»nposed to destroy more cock- 
chafers than all their other enemies, attacking and killing the females at 
the moment of oviposition, and thus preventing the birth of thousands of 
young grubs. Lastly come the Brachyptera, many of which prey upon 
insects as well as on putrescent substances. Mr. Lehmann tells us that 
some of them are very useful in destroying a weevil (Apion flavifemo- 
ratum®), the great enemy of our crops of clover seed. 
Amongst the devourers of insects in their perfect state only, must be 
ranked a few of the social tribes, ants, wasps, and hornets. The first- 
mentioned inde“atigable and industrious creatures kill and carry off great 
numbers of insects of every description to their nests, and prodigious are 
their efforts in this work, I have seen an ant dragging a wild bee many 
times bivger than itself; and there was brought to me this very morning, 
while writing this letter, an E/ater, quite alive and active, 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 off alive, such as a cock- 
roach, &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 incredible labour, carry 
it up to their nest. Madame Merian, 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 animals; and Myrmica 
omnivora is very useful in Ceylon in destroying the former insect, the 
larger ant, and the white ant.® 
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 conse- 
quence of this circumstance, flies in many places were so extremely nume- 
rous 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 suke of 
their services in driving away the flesh-fly; and, if we may believe the 
author of Hector St. John’s A verican Letters, the farmers in some parts of 
the United States are so well aware of their utility in this respect, as to 
suspend in their sitting rooms a hornet’s nest, the occupants of which 
prey upon the flies without molesting the family. There are other de- 
vourers of insects in their perfect state, the manners and food of whose 
larvee we are unacquainted with. St. Pierre speaks of a lady-bird, but it 
robably belonged to some other genus, of a fine violet colour, with a 
head hke a ruby, which he saw carry off a butterfly.” Linné informs us 
that Clerus formicarius devours Anobium pertinax. A fly related to Panorpa 
communis appears created to instil terror into the pitiless hearts of the 
1 Latr. Hist. Nat. x. 181. 
2 Linn, Trans. vi. 149. Kirby, Ibid. ix, 42, 43. 
5 The late R. Kittoe, Esq. 
+ Voyages, i. 185, . 5 Percival’s Ceylon, 307. 
6 Mr. Knight made the same observation in 1896, and supposes the scarcity of 
rab ans from the want of males to impregnate the females, Philos, Zyans. 
> p. 243, 
7 St. Pierre, Voy. 72 
