[54 



SOME SOUTH INDIAN INSECTS. ETC. [CHAP. XVI. 



object of girdling the twigs in this way being to provide a suitable 

 amount of food free from sap, for the larva.- to feed on. The larvae 

 of most longicorn beetles, it may be noted, feed on dead wood. 



Blister Beetles of various species often do great damage to crops 

 h\ devouring the flowers and tender shoots. Cereals and legumi- 

 nous crops, such as gram, are especially subject to attack and there 

 seems to be some special attraction for these beetles in flowers of a 

 yellow colour; the common red-barred black Zonabris pustulata, for 

 example, feeds indifferently on yellow flowers such as those of red 

 gram, cotton and prickly-pear. Whether these beetles are to be 

 ranked as pests or beneficial insects is at present, however, an open 

 question. In the adult state they certainly do harm to crops. The 



Fig. 71.— A Blisti i beetle | Mylabris indica . 

 1 he small outline figure shows the natural size. (Original.) 



bfe-histories of very few species are known at all but the larvae of 

 most of those that are known are parasitic on the eggmasscs of 

 grasshoppers; and we have bred two distinct species of blister- 

 beetle- (one ot which is apparently Gnathospastoides rouxi, Cast) 

 from eggmasses ot the destructive Deccan grasshopper (Colemania 

 splienarioides). It therefore the larva of a blister-beetle destroys 

 even one eggmass containing (say) forty eggs of a grasshopper, the 



