INDIRECT BENEFITS DERIVED FROM INSECTS. 191 



they can either run or fly, renders hopeless any attempt to elude their 

 pursuit. Their larvae are also equally tremendous with the imago,, having 

 eight eyes, four on each side, seated on a lateral elevation of the head, 

 two above and two very minute below, which look like those of spiders, 

 and besides their threatening jaws armed with a strong internal tooth, 

 being furnished with a pair of spines resembling somewhat the sting of a 

 scorpion, which stand erect upon the back of the abdomen, and give 

 ihem a most ferocious aspect. This last apparatus, according to Clairville, 

 serves the purpose of an anchor for retaining them at any height in their 

 deep cells. ^ Most of the aquatic beetles, at least the Gyrini and Dytisci, 

 prey upon other insects both in their first and final state. The larvae of 

 the latter have long been observed and described under the name of SquillcB, 

 and are remarkable for having their mandibles adapted for suction like 

 those of Hemerobius and Myrmeleon ; but they are not, like them, 

 deprived of a mouih, being able to devour by mastication as well as by 

 suction. Another tribe of this order which abounds in species, those 

 predaceous beetles which form Linne's great genus Carabus (EutrecKxnaF) , is 

 universally insectivorous. One of the most destructive is the grub of a 

 very beautiful species, an English specimen of which would be a great 

 acquisition to your cabinet, it being one of our rarest insects^, I mean Calo- 

 soma Sycophanta. This animal takes up its station in the nests of Cnetho- 

 campa processionea and other moths, and sometimes fills itself so full with 

 these caterpillars, which we cannot handle or even approach without inju- 

 ry, as to be rendered incapable of motion, and appear ready to burst. 

 Another beautiful insect of this tribe, Carabus auratus, known in France 

 by the name of Vinaigrier, is supposed to destroy more cockchafers 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 Jlavifemoratum^) , 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 indefatigable 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 bigger than itself; and there was brought to me, this very morning, 

 while writing this letter, an Elater 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- 



' Entom. Htlvetique, ii. 158. 



* In ihe former edition of this work (Vol. IV. p 392.), this tribe is denominated Eupo- 

 dixxa ; but as this seems too near to M. Latreille's Eupoda, belonging to a different tribe of 

 beetles, we have substituted the above name, which means the same. 



3 One was taken at Aldeburgh in Suffolk by Dr. Crabbe, the celebrated poet; another by 

 a young lady at South wold, which is now in the cabinet of Joseph Hooker, Esq.; and a 

 third by a boy at Norwich, crawling up a wall, which was purchased of him by S. 

 "Wilkin, Esq. * Lair. Hist. Nat. x. 181. 



5 Linn. Trans, vi. 149. Kirby, Ibid. ix. 42, 43. « The late R. Kiltoe, Esq, 



