230 INDIRECT BENEriTS 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 Telephorus. 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 in- 

 sects. 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 tremen- 

 dous 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 be- 

 sides their threatening jaws armed with a strong internal 

 tooth, being furnished with a pair of spines resembling some- 

 what 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 larvae of the latter have long been observed and 

 described under the name of Squillce, and are remarkable for 

 having their mandibles adapted for suction like those of He- 

 merobius and Myrmeleon ; but they are not, like them, de- 

 prived of a mouth, being able to devour by mastication as 



populous city of Bristol. This was most probably owing to the circumstance of 

 the garden having had brought into it a quantity of fresh earth which appa- 

 rently had been dug 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 Stylops 

 (in one instance of three), or evident signs of a Stylops having escaped from them. 

 These singular little animals, whose economy and systematic place are equally 

 perplexing, Mr. Thwaites informs us " arc 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 appearance in flying very difi^erent from that 

 of any other insect. (Thwaites in Trans. Ent. Soc. Lond. iii. 67.) 



1 Preys. B'dmisch. Insekt. 59. 61. 2 Entom. Helvetique, ii. 158. 



