132 On the Life Histortf of " Wireivorms" 



pupae have been found from the latter end of July up to the middle of 

 September. 



It is often stated, for instance by Miss Ormerod(i8), that the larva de- 

 scends for a considerable distance beneath the surface to pupate. Reh (20) 

 however says that it pupates close to the surface ("in geringer Tiefe") 

 up to a depth of 10-15 cm. This also has been my experience, principally 

 with A. ohscurus, the following being records from my note book of 

 two tests made by digging in the sod heaps at Windermere, each to a 

 depth of one foot. 



5. viii. 18. 2 



pupae at 1" from surface 6. viii. 18. 1 pupa at 1" from surface 



pupa ,, 2 

 „ less 3" 

 „ „ 3" 



„ „ 4" 



2 pupae ,, 1-2" 



1 pupa „ 2" 



1 „ „ 3" 



2 pupae ,, less 4" 

 1 pupa „ 4" 



Larvae pupating in pots at Rothamsted were similarly found in some 

 cases quite near the surface and though they are found to a much 

 greater depth than those mentioned, the habit of pupating deep in the 

 soil, beyond the depth of a plough, is by no means universal. 



Natural Enemies. 



This subject has been so thoroughly dealt with in the paper by 

 Ford (11) already quoted, that there is but little to add. In confirmation 

 of the value of birds in reducing the number of "wireworms," reference 

 may be made to the work of Miss Laura Florence at Aberdeen (lO) 

 especially in regard to the quantity consumed by other gulls than the 

 black-headed gull, which has been well-known as an ally of man in this 

 respect. Hammond's work (14) on the food of birds in the Eastern Counties 

 of England is also of great value, bringing out, amongst other points, the 

 fact that the skylark is of assistance in the control of these pests. 

 Berry (3) found many wireworms in the crops of pheasants in Scotland, 

 but Evershed and Warburton (9) appear to have found but few. Probably 

 local and temporary conditions account for the difference. 



There is no doubt that birds are one of the most important factors 

 in the natural control of wireworms and it is probable that under 

 conditions where such a course is possible, their numbers might be 

 appreciably reduced if poultry, especially those of good foraging strains, 

 were run for a time on land newly ploughed out of grass. 



Wireworms do not appear to be attacked by internal parasites to 

 any great extent. Marsham(i7) records that liierkander found six out of 



