BENEFICIAL INSECTS. 



the air ; large numbers can be seen in a wheat-field where aphis s 



abundant. These flies deposit small 

 white eggs singly on the wheat near the 

 \ / colonies of aphis; a maggot hatches, 



I / formed like the typical fly maggots, 



^y vafip s- thick at the hind end, tapering to a 



^^^^^^ point at the headless front end, with a 



^^^Bfc^^. pair of strong hooks in the mouth; 



j ^l \^ the maggot is green and moves slowly 



/^ ^\ ^V ^ about the leaf, feeling in every direc- 



/ V tion. It is blind and strikes about 



sT \. 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 1 is very common in 



FIG. 343. 



Ground Beetle 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 

 upon special destructive insects. 

 The Sk-spotted Tiger Beetle 2 is 

 abundant in rice-fields in Bengal ; 

 it flies with great rapidity and feeds 

 upon the Rice Bug. A ground 

 beetle 3 is said to feed upon the 

 young North- West locusts. The 

 larvae of other ground beetles feed 

 upon such caterpillars as live 

 exposed on 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- 



FIG. 344. 

 The Six-spotted Ground Beetle. 



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



l Syrphus agyptius. Wied. (Syrphidse.) j a Cicindela sexpunctata L. (Cicindelidse.) 

 3 Calosoma orientate Ho. (Carabidse.) 



