2<>4 SOME SOt IH INDIAN INSECTS, ETC. [CHAP. XXI. 



the solitary wasps, are commonly seen in bungalows. A few 

 species, however, arc known to parasitize grasshoppers, their larvae 

 feeding on the egg-masses, and are therefore beneficial. We have 

 bred an undetermined species from the egg-masses of the Deccan 

 Grasshopper (Colemania sphenar hides). 



Amongst other parasites of grasshoppers must be reckoned the 

 Blister Beetles, whose larvae feed on and destroy the egg-masses 

 of grasshoppers, and these beetles are therefore highly beneficial 

 in their early stages, whatever damage they may do as adult 

 insects. 



Besides doing good as predators and parasites, insects may be 

 beneficial indirectly in other directions, as in checking the growth 

 of weeds, breaking up of dead wood and acting as scavengers of 

 dead animal matter. As regards the checking of weeds, there are 

 few if any plants which arc not subject to attack by insects of 

 some or many kinds and weeds are no exception to this rule. But, 

 whilst insects may do a little good by checking the growth of 

 weeds, this is hardly a factor to be relied on by the agriculturist 

 to supersede the necessity of weeding, and on the other hand many 

 insect pests breed freely on weeds and thereafter invade the 

 adjacent crops and damage them. In forest regions especially, 

 where there is always a quantity of dead wood present, this has a 

 regular and characteristic fauna of its own which feeds upon it 

 and rapidly reduces the dead wood to a state in which it can again 

 form part of the soil, and in such cases the action of these insects 

 is undoubtedly beneficial under natural conditions. Dead animal 

 matter has also a special fauna of its own, various insects feeding 

 On it and laving their eggs on it so that it is rapidly consumed. 

 The Dung Beetles of numerous kinds are common and well-known 

 examples, the beetles separating small pieces of dung which they 

 form into a ball and roll along the ground to a suitable spot, where 

 it is buried and either eaten by the beetle itself or an egg laid on 

 it and the ball left for the food of the future larva. In the case of 

 si line of the larger species, such as Heliocopris bucephalus (see 

 figure 121), the ball may be very large and solid, as much as six 

 inches in diameter, and may be buried at a depth of several feet. 

 The dispersal and reduction of dead animal matter by insects in 

 this way is obviously beneficial by ensuring its more rapid 

 blending with the soil. 



