A HISTORY OF KENT 



Mr. Lewis has also found eight galls formed by the following Cynipidx in Kent : — 

 Xestophnes potentillae, Cam. Rhodites rosae, Htg. 



Aulax glechomse, Htg. — eglanteriae, Htg. 



Diastrophus rubri, Htg. — nervOsus, Curt. 



ENTOMOPHAGA 



Ichneumori-Jiies, etc. 



This is by far the most extensive and perplexing section of the 

 Hymenoptera. It is also the one that has been studied least, and it is 

 safe to say that a large number of the species occurring in Kent have not 

 even been described. This section therefore presents an exceptionally 

 interesting and promising field for entomological research. 



The Entomophaga are parasites of the most pronounced kind ; they 

 deposit their eggs inside the bodies of other insects, and the larv£e feed 

 on the living tissues, avoiding the vitals until the fleshy portions have 

 been devoured. For this purpose the female is armed with a sting-like 

 ovipositor, which varies in length. In some of the groups the ovipositor 

 is visible — sometimes it is long — but in others it is concealed. 



The Entomophaga prey mostly upon common species of insects. A 

 few of them confine their attacks to single species, but the majority feed 

 on a variety of species, and attack them in the larval stage. It is usual 

 for a number of specimens to inhabit the body of one caterpillar, and the 

 parasites are almost sure to cause death eventually, although cases are on 

 record in which the victim has arrived at the perfect stage. The 

 victims of many of the Entomophaga are destructive to crops, and were 

 it not for the attacks of the parasites the damage they might do would 

 be very great. The ichneumon-flies are therefore of the greatest 

 economic value, and few insects have a more important part to play in 

 maintaining the balance of nature. 



The species vary in length from about an inch to less than 

 a millimetre. A large number of the species are exceedingly minute, 

 and can only be properly examined under a powerful lens. 



The Entomophaga have been collected to some extent in Kent, and 

 several interesting species have been taken. One or two of these will be 

 mentioned in the following brief notice of each of the main groups. 



Ichneutnonida. This is one of the largest groups, and probably 

 over a thousand species exist in the county, of which only about 300 

 have been recorded. Relative to those of other groups the majority of 

 the species are large. They are slender insects. Many of them are 

 black with yellow and red markings, and the antenns and legs are more 

 or less yellow. The large brightly-coloured species chiefly belong to the 

 extensive group of which the genus Ichneumon, L., is the type. Rhyssa 

 persuasoria, L., has occurred lately near Dover ; it destroys the larvs of 

 Sirex gigas. This ichneumon-fly is nearly an inch in length, and the 

 ovipositor, which is used to drill holes into trees infested with the 

 Sirex larvas, is itself longer than the body. 



Braconidce, This is a moderate-sized group, of which probably over 



