19-22.] 



The Arri.E Blossom Wervh. 



G39 



take place during the larval life and the last of these reveals 

 the pupa or chrysalis, which occupies the capped blossom for 

 about a week, at the end of which period the young adult 

 emerges, and, :ifter hardening up, cuts its way out. 



The young adult weevil emerges about the beginning of J une 

 in early seasons, but not until the end of June in late seasons, 

 and spends about a month feeding on the under-surfaces of 

 the young leaves of the apple (Fig. 3). It discards the lower 

 epidermis and feeds on the mesophyll or internal leaf tissue 

 leaving the upper epidermis intact. Feeding goes on for from 

 three weeks to a month, at the end of which time the weevils 

 begin to seek winter quarters, selecting the following sites : — 



(«) Cracks and crevices in the trunks of apple, pear and plum trees and 

 any other trees near the plantations. Cajiker spots are often 

 selected. 



(h) Dead leaves, heaps of refuse, and under old grease hands where a 



paper foundation is used, 

 (c) Hedge hottonis and in the sf)i]. 



Certain conditions seem to be necessary in the winter site 

 selected, and the result is that when these conditions are ful- 

 filled large numbers of hibernating weevils may be found close 

 to each other. In Worcestershire, the principal hibernating 

 quarters of the large bulk of weevils in plantations of smooth 

 barked trees were found to be under the paper of old grease 

 bands on both plum and apple trees. 



Natural Enemies. — The Apple Blossom Weevil suffers to 

 some extent from the attacks of birds, fungi, and insects. The 

 birds which chiefly take the adult weevil are the woodpecker, 

 tits, nuthatch and chaffinch, w^hile the sparrow is recorded as 

 pecking open the ' ' capped ' ' blossoms and taking the larv?e 

 or pupae. 



At Long Ashton many dead weevils were found during the 

 winter; these had all been killed by a fungus which was appa- 

 rently a species of Isaria, a common insect-attackino- fungus. 



The principal insect enemy of the Apple Blossom Weevil is an 

 Ichneumon fly, Pimj^Ia pomomm (Ratzl. The female parasite 

 seeks out the young flow^ers infested with weevil grubs and 

 therein lays an egg either on or near the body of the grub. 

 This egg hatches and the young parasite, emerging, attaches 

 itself to the larva or pupa of the weevil and proceeds to feed, 

 growing very rapidly at the expense of its host which is finally 

 destroyed. Dr. Imms, of the Department of Plant Pathology 

 at Eothamsted, has shown" that this parasite is recorded as 



* Aimals of Applied BioloL'-y, Vol. IV, 1917, No. 4. ^ 



