U)'2 The Larval and Pupal Stages q/'Agriotes obscurus 



feed on organic matter in the soil. The medium and large stages were 

 almost invariably observed feeding (with the exception mentioned 

 above in the case of the larger stage), and it seems that they feed con- 

 tinuously, save in the months of December to February inclusive. 

 This observation was obtained from regular examination of potatoes 

 placed in the breeding pots. Feeding is usually active by March and 

 seems to decrease at the end of November. It is very difficult to starve 

 these wire worms. Of 10 large wire worms placed in sifted soil without 

 food November 3rd, 1914, nine were present January 22nd, 1915, and 

 seven on March 8th, 1915. The three missing ones had probably been 

 eaten by the others, as traces of the skins were found. These seven 

 larvae had thus existed in soil free from any vegetable matter visible 

 to the naked eye for 125 days; of the seven larvae only one remained 

 on May 4th, 1915. In a duplicate experiment under similar conditions, 

 10 larvae lived from November 3rd, 1914, to February 11th, 1915, i.e. 

 100 days. The larvae will tolerate a large amount of moisture, and 

 will exist for at least a week in water-logffed soil. On the other hand, 

 wireworms kept in soil not supplied with water and allowed to dry up 

 will die after a couple of days. It is hard to explain their independence 

 of vegetable growth (such as pasture grasses and various crops) for 

 food, in any other way than by assuming that they feed on the organic 

 matter in the soil. This would help to explain the usual occurrence 

 of these larvae in the lighter soils plentifully supplied with organic 

 matter. In several cases, small and medium sized larvae were found 

 buried in the farmyard manure under growing potatoes. It could not 

 be said definitely that the larvae were feeding, but the condition of 

 the mouth parts seemed to indicate that they were. 



The usual depth at which these wireworms are found in the soil 

 varies from one inch in pasture, to eight or nine inches in potato fields. 

 In winter they bury themselves much deeper, and were found as much 

 as two feet deep in the large drainpipes previously described. 



The larvae bury themselves in soil surprisingly quickly, though their 

 rate of progress on the surface is comparatively slow. 



Eighty-three larvae had buried themselves at least two inches deep 

 in soil, of about the same consistency of that in a potato field, in less 

 than twenty minutes. On being exposed to light, they immediately 

 travel in the opposite direction to the source of the light. They travel 

 slowly, but fairly easily on an unpolished surface, and often progress 

 carrying the abdomen bent in a slight curve to one side. This is one 

 of the difficulties that hinder accurate longitudinal measurement. 



