PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 205 



Can you tell us something more about it, Mr. Sen ? 



Cryptorrhynchus gravis does great damage to mango fruits in Bengal, jjj^ p^ q^ gg^^ 

 The grub bores into the fruit and makes it useless, eating its way through 

 the pulp. In some trees all the fruits are attacked. It is a regular 

 pest attacking the same tree every year. The early maturing varieties 

 of mango are more attacked than the late ones. 



Life-history. — Early in April the female weevil lays small white eggs 

 (about 0"5 mm. long) on the surface of the fruit when it has attained 

 nearly half its size. The egg is covered by a coating of black hard sub- 

 stance giving the appearance of a black spot which is about 1 mm. long. 

 From the egg hatches out a tiny white legless grub in a week or so which 

 bores into the fruit and feeds within. The black coating then falls off and 

 the wound also heals up to such an extent as not to be easily detected. 

 The grub has 11 body segments. It continues to feed within till it 

 is fijllgrown in about a month. It then pupates inside and subsequently 

 the weevil emerges by cutting its way out of the fruit. The life-history 

 occupies about a month and a half. It has only one brood in the year. 

 Immediately after the mango season and during the rains it has been 

 found to hibernate in the bark of the affected tree either in its natural 

 cracks or amongst the roots of epiphytes growing on them. 



It is a very bad pest in Eastern Bengal and Assam," but does not Mr. Ghosh, 

 occur in Western Bengal although fruits from Eastern Bengal are carried 

 all over the country. I brought some infected fruits to Pusa and found 

 that the grubs did not live here after September. 



It is peculiar that, although these fruits are exported in such quantities, Mr. Fletcher, 

 this weevil does not spread into adjacent mango-growing areas. 



It is believed in Sylhet that the same trees are attacked year after Mr. Ghosh, 

 year and that neighbouring trees are not affected. But that is not a 

 fact, for all trees are attacked indiscrimmately. I found wild mango 

 trees growing isolated in the jungle and these trees bore very small fruits, 

 but even in these the weevils were present. This is an insect which 

 requires working out. 



It is a bad pest throughout Assam. Mr. Gupta. 



Cryptorrhynchus poricollis, Fst. 



Entl. Note 28 ; Proc. Second Entl. Meeting, p. 225. 



Specimens of this weevil were found under bark at Dacca on 27th Mr. Fletcher. 

 July 1911 by Mr. Nowroji who was sent to investigate the damage done 

 by C. gravis. It has also been found underground in the adult state by 

 Mr. Sen at Dacca. It is not definitely known that this species attacks 

 mango. 



