INDIRECT BENEFITS DERIVED FROM INSECTS. 271 



breeding. The species at present known are formed 

 into two genera, Xenos and Stylops, which are confined 

 to Melitta* and Fespa b . 



The next description of insect destroyers are those 

 which devour them in their Jirst and last states. No 

 beetles are more common after the summer is confirmed, 

 than the species of the genus Telephones. Preysler in- 

 forms us that the grub of T.fuscus destroys a great many 

 other larvae c , and I have observed the imago devour 

 these and also Diptera^-L\m\& has with justice denomi- 

 nated the Cicindelce the tigers of insects. Though de- 

 corated 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, 

 /our 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 scor- 

 pion, which stand erect upon the back of the abdomen, 

 and give them a most ferocious aspect d . This last ap- 

 paratus, according to Clairville, serves the purpose of an 

 anchor for retaining them at any height in their deep 

 cells e . Most of the aquatic beetles, at least the Gyrini 

 and Dytisci, prey upon other insects both in their first 



a Kirby's Mon. Ap. Aug. ii. 1 10-1 13. b Rossi Fn. Etrusc. Mant. 

 c Preys. Bomisch. Insekt. 59. 61. d PLATE XVII. FIG. 13. 



e Entom. Helvetique, ii. 158. 



