ENEMIES OF APHIDES. 165 



19. — Head much longer than its width between 



the eyes ... ... ... Cardiastdhus. 



20, — Species elongate, glabrous, parallel-sided. Xylocoris. 



The only one of these genera which is definitely shown to 

 comprise aphis-eating species is Ani/wcoris, but it seems probable 

 that continued observation may reveal the same habit in others, 

 particularly in Tetraphleps (Fieb.) and perhaps Acompocoris (Reut.). 

 The genus Piezostethus (Fieb.) contains one species, L.formicetorum 

 (^Boh.), which appears to find a suitable home in the nests of 

 Formica rubra. Hence, it may be found under these conditions 

 in company with aphides possessing the same habit. 



The details of the genus Anthocoris will be given later on. 

 The family Capsidce — which, although very often stated to 

 contain vegetable feeders only, includes, as has been mentioned, 

 several genera of more or less carnivorous proclivities, whilst the 

 species of two genera can be demonstrated to consume aphides 

 as ordinary food. It is a numerous family, exhibiting a great 

 variety of structure, of environment, and habit ; but the patient 

 observation of the student is not unlikely to be rewarded by the 

 addition of some of its genera to the list of Aphis-eaters, in 

 addition to those of Capsus and Plagiognathiis. 



The following tabular account of the genera of the Capsidce. is 

 taken from Mr. Saunders' exhaustive work : — 

 I. — Head channelled in the centre or trans- 

 versely impressed on the vertex ; ante- 

 rior margin of pronotum not callosely 

 raised ... 

 2. — First joint of the posterior tarsi much 



longer than the second 

 3- — Head channelled down the middle 

 4. — Base of pronotum truncate, covering the 



base of the punctured scutellum .,. Miris (Fab.). 

 5- — Base of pronotum emarginate, not 

 covering the base of the impunctate 

 scutellum ... ... ... Megalocera:a{¥\Q!o.) 



6. — Head transversely impressed on vertex.. 

 7- — Eyes not, or scarcely, projecting beyond 



the lateral margin of the pronotum ... Acetropis (Fieb.). 



