A. D. Imms 223 



four dorsal. The apical region of the abdomen is prolonged posteriorly 

 into a pair of short appendages, which are imperfectly two-jointed, and 

 rounded at their extremities. On either side of these appendages, is a 

 pair of papillae, each carrying a conspicuous curved spine, considerably 

 longer than the spines on any of the preceding segments ; a pair of smaller 

 spines are also present ventrally. 



Length 5 mm.; maximum breadth across the thorax 1-5 mm. 



9. THE FEMALE PUPA. 



The female pupa (Plate XII. fig. 4) differs from the male pupa in that 

 the antennae extend as far backwards as the sixth abdominal segment 

 while the hind legs reach to the seventh segment. The terebra is folded 

 back over the dorsal side of the abdomen, its apex reaching to the middle 

 of the first segment. The latter is unarmed, but the second and third 

 segments are each provided with a pair of small dorsal spines. The fourth 

 segment has four similar dorsal spines and two ventral spines; vestiges 

 of a second and outer pair of ventral are also present. The fifth segment 

 is armed with four dorsal, two ventral and two prominent lateral spines 

 — one on either side. The sixth segment has usually six ventral, four 

 dorsal and large lateral spines. The seventh or apical segment is pro- 

 vided, on either side, with a pair of large curved ventro-lateral spines as 

 in the male, and, furthermore, is prolonged backwards in the form of a 

 pair of unjointed appendages each surmounted by a conspicuous spine. 



Length 4-25 mm. to 4*45 mm. ; maximum breadth across the thorax 

 1-5 mm. 



10. EFFICIENCY AS A PARASITE. 



Between May 25th and 29th, 1916, 1270 apple buds, harbouring the 

 weevil in various stages of development, were separately examined under 

 a binocular microscope. Among these infested buds 349 contained larvae 

 of Pimpla pomorum. This gives a ratio of parasitism working out at 

 27-4 per cent., which is a relatively high one, and remarkably near to 

 that found by Decaux to be efiicient in France in the control of the 

 weevil by means of species of Braconidae. A further 605 buds gave in- 

 conclusive results, and are not included in this enumeration. Many of 

 them were either attacked by mould or were empty, or contained dead 

 or sickly hosts, without certain indications of being parasitised by the 

 Pimpla. The appearances in many cases suggested that the parasite had 

 been present, but had died along with the host. Mould favoured by wet 

 weather, appeared often to kill the latter when parasitised, and the 

 parasitic larva usually died also as the result. When the petals of the 



