The Tea insects of India. 



its eggs on the ground, From these eggs emerge small curved white 

 grubs armed with powerful jaws with which they bite off the roots of 

 plants. These grubs never quit the ground. They moult at intervals 

 and gradually grow bigger until ih->y become of the size shown in the 

 left hand bottom figure, or even bigger than this. They then moult 

 their shins for the last time and transform into white motionless 

 creatures (or pupse), one of which is depicted, natural size, in the right 

 hand bottom figure. The pupa lies dormant for a time in the ground, 

 and then its skin splits down the back, and out of it emerges the 

 beetle which makes its way out of the ground. The beetle flies about 

 for a time and perhaps eats a few leaves, but its chief object in life is to 

 find a mate and to become the parent of another generation. Thus the 

 circle goes on continuously. 



With regard to the time spent by the insect in its various stages of 

 growth all that we know is as follows. A number of nearly full-grown 

 grubs, sent to the Indian Museum, Cale itta, from Darjiling in October 

 1891, remained in the earth at the bottom of the breeding-cage in 

 which they were kept, until the following February, when a beetle 

 emerged. This shows that the insect passes the cold weather in the 

 ground, for in the moist warm climate of Calcutta it is certain to 

 develop at least as fast as in the hills, and possibly considerably faster. 

 The beetle of a species belonging to the same family has been noticed 

 by the writer emerging in large numbers from the ground, on the Cal- 

 cutta maida>i,m the latter part of the hot weather, so the probabilities 

 are that the hot season is the usual time for emergence. Under these 

 circumstances the eggs would be likely to be laid about the beginning 

 of the rainy season in I>3oithern India ; but this point requires confirma- 

 tion. How long is spent by the grubs in the ground before they become 

 full grown we do not know, but the fact that the European species 

 Melolontha vulgaris, Fabr., spends more than three years in this stage,^ 

 while the American species MacrodactyUis svhspitiosns, Fabr., spends the 

 greater part of one year,^ leads to the supposition that an equally 

 long period may be required in India. Much, no doubt, depends upon 

 the climate of the locality ; for warmth and damp are almost certain to 

 accelerate development, whereas dryness and cold retard it. In any case, 

 a generation of the insect is almost certain to occupy one year, and it is 

 quite possible that it takes two or even three years to complete. 



On Ceylon coffee estates, where Melolonthini larvse at one time 

 proved very troublesome, the only method of treatment that seems to 

 have been at all successful was digging out the grubs by hand; and this, 

 though very costly, was generally admitted to be the most satisfactory 

 method of dealing with the pest- 



' Ormerod. * Packiini, 



