156 INDIRECT BENEFITS DERIVED FROM INSECTS. 



The next description of insect destroyers are those which devour them 

 in their first and last states. No beetles are more common after the 

 summer is confirmed than the species of the genus Tclephorus. Preysler 

 informs us that the grub of T.fuscus destroys a great many other larvae^ ; 

 and I have observed the imago devour these and also Diptera. Linne has 

 with justice denominated the CicindelcB the tigers of insects. Though 

 decorated with brilliant colours, they prey upon the whole insect race ; 

 their formidable jaws which cross each other are armed with fearful fangs, 

 showing to what use they are applicable ; and the extreme velocity with 

 which 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 

 them 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 larvje of 

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

 Squilhe, 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 mouth, being able to devour by mastication as well as by 

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

 predaceous beetles whicli form Linne's great genus Carabus (Eutrechina^), 

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

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

 acquisition to your cabinet, it being one of our rarest insects **, I mean 

 Calosomn Sycophanta. This animal takes up its station in the nests of 

 Cnethocampa processionea and other moths, and sometimes fills itself so 

 full with these caterpillars, which we cannot handle or even approach 

 without injury, as to be rendered incapable of motion, and appear ready 

 to burst. Another beautiful insect of this tribe, Carabus auratus, known 



from some bank or pathway, containing many of the nests of Andrena convexiuscula, 

 which also abounded in the garden at the same time, and of which Mr. Thwaites 

 captured several, all containing the larva of a Sii/lops (in one instance of three), or 

 evident signs of a Sti/lops having escaped from them. These singular little animals, 

 whose economy and systematic place are equally perplexing, Mr. Thwaites informs 

 us, " are exceedingly graceful in their flight, taking long sweeps as if carried along 

 by a gentle breeze," which, and their large expanse of wing, give them an appear- 

 ance in flying very different from that of any other insect. (Thwaites in Trans. Ent. 

 Soc. Loud. iii. 67.) 



1 Prej'S. Bomisch. Insekt. 50. Gl. 

 • 2 Entom. Hetvetique, ii. 158 



5 In the former edition of this w'ork (Vol. IV. p. 392.), this tribe is deno- 

 minated Eupodina ; but as this seems too near to M. Latreille's Eupoda, belong- 

 ing to a diflerent tribe of beetles, we have-substituted the above name, which means 

 the same. 



* One was taken at Aldeburgh in Suffolk bv Dr. Crabbe, the celebrated poet ; 

 another bj' a young lady at Southwold, which is now in the cabinet of Joseph 

 Hooker, Esq. ; and a third by a boy at Xorvvich, crawling up a wall, which was pur- 

 chased of him by S. Wilkin, Esq. 



