AGRICULTURAL ENTOMOLOGY 239 



occur when conditions are favourable. The caterpillar tunnels mtoa 

 single gram, and us in the case of the wheat weevil it remains 

 invisible until just before it transforms into a chrysalis. It then cuts 

 a small round valve-like door which is -pushed open by the emerging 

 moth, after it lias worked its way through the slight silken cocoon 

 in which the chrysalis is wrapped. The insect passes the winter in 

 the caterpillar stage inside grain stored in granaries. A temperature 

 of 104 degrees Fahrenheit, when continued for two days, is said to 

 have been found sufficiently high to destroy the insect, which is 

 therefore essentially the inhabitant of temperate regions, and is little 

 likely to prove destructive in the plains of India, though it may do a 

 good deal of damage in the hills. 



In this connection I may observe that there is a somewhat similar 

 insect, which may perhaps be Tinea graneUa, which attacks stored 

 dhan in Bengal to a considerable extent. It differs from Gelechia, 

 cerealetta in living to a greater extent outside the grains, and in 

 spinning the grains together into a silken web, also in pupating in 

 cracks and corners of the granary. In both cases, however, old 

 infested granaries are the sources from which infection arises, so that, 

 clearing up the old granaries and removing all the old infested gram 

 before bringing in the new crop is certainly likely to be of use, 

 though the fact that the eggs of the Anjoumois moth are sometimes 

 laid upon grain standing in the fields makes its eradication more 

 difficult than is the case of such a purely granary pest as the wheat 

 weevil and the dhan moth. 



The next insect which I have to show you is the palm weevil 

 (Bhynchophorus ferruginem) , which has been sent to me during the 

 past year, as attacking date palms both in Saharanpur and Lucknow, 

 The insect has long been known as destructive to cocoanut palm trees 

 and often does a great deal of damage. According to Mr. Ridley 

 who investigated the habits of the insect in Singapore, the beetles fly 

 at night and deposit their eggs at the base of the leaf stalks, any 

 mechanical injury, and especially holes made by the rhinoceros 

 beetle in the stalks, being taken advantage of for the purpose. The 

 arvae tunnel into the heart of the trees, the chrysalids being formed 

 in Gocoons made of fibre in the burrow. When badly attacked the 

 trees generally die, but w T hen they are only slightly attacked they 



