278 



Beneficial insects. 



the air; larg'c numbers can be seen in a wheat-field where aphis is 



abundant. These flies deposit small 

 wliite egg's singly on the wheat near the 

 colonies o£ aphis; a maggot hatches, 

 formed like the typical fly maggots, 

 thick at the hind end, tapering to a 

 point at the headless front end, with a 

 pair of strong hooks in the mouth; 

 the maggot is green and moves slowly 

 about the leaf, feeling in every direc- 

 tion. It is blind and strikes about 

 it in a curious tentative fashion, feeling 

 for a victim. The plant-lice caught 

 by it are drawn in with the hooks, 

 sucked out dry and thrown aside. 

 These maggots demolish whole colonies 

 of the plant-lice and finally turn to 

 one species^ is very common in 



Fig. 343. 



Ground Beefle that attacks the young 



North- West Locust. 



the pupa on the leaf. At least 

 the plains, feeding on aphis of all 

 kinds. 



Many insects are found feeding 

 Upoti special destructive insects. 

 The Six-spotted Tiger Beetle^ is 

 abundant in rice-fields in Bengal ; 

 it flies with great rapidity and feeds 

 upon the Rice Bug. A ground 

 beetle ^ is said to feed upon the 

 young North- West locusts. The 

 larvae of other ground beetles feed 

 Upon such caterpillars as live 

 exposed oil the plant ; these are 

 small slender black insects, which 

 congregate on plants infested 

 with small caterpillars and destroy 

 them. 



There are in addition many 

 insects which prey promiscuously, 

 their life history not being speci- 

 ally modified in relation to their prey as in predators discussed above. 



^Syrphus cpgyptius. Wied. (Syrphidie.) ) ^ Ciciiidela sexpunctata L. (Cicindelidse.) 

 ^ C'alosoma orientale Ho. (Carabidte ) 



Fio. 344. 

 The Six'SjJotled Ground Beetle. 



