March 1895.] INJURIOUS INSECTS AND FUNGI. 



318 



The larva, or wirevv^onn, of Agriotes lineatus (Fig. 4) is 

 from six to seven-eighths of an inch long, very shiny, and of 

 yellow colour, becoming more chestnut coloured when dead. 

 It has a few hairs on its body, and three pairs of four-jointed 

 legs on the first three segments, and a sucker foot on the 

 terminal segment. It has very strong mandibles or jaws 

 meeting over the mouth, well adapted for biting roots and 

 fibres. With these jaws it quickly tears away the soft parts of 

 the slightly bulbous stems of wheat, oat, and barley plants just 

 above the roots, and kills the plants ; it also bites off the 

 sprouting bines in hop hills, and. the slender roots of young 

 turnips, mangels, carrots, and parsnips. 



After a long period of life, varying from three to five years, 

 according to circumstances, the larva goes down deep into the 

 earth, makes a little oval cocoon of particles of soil, and changes 

 to a pupa (Fig. 5), from which the beetle emerges in two or 

 three weeks. 



The larva of Agriotes sputator, said by Taschenberg to be 

 especially fond of salad plants, is smaller than that of Agriotes 

 lineatus^ but similar in shape and general appearance, and the 

 larva of Agriotes ohscnrus is much like thafc of Agriotes 

 lineatus in si i ape, size, and colour. 



Methods of Prevention and Remedies. 



From the experiments at Cornell University Station, alluded 

 to above, Messrs. Comstock and Slingerland conclude that it is 

 almost impossible to extirpate wireworms by any of the means 

 there adopted. These experiments embraced an endeavour to 

 protect seeds, which are so liable to attack just after germination, 

 by coatings of Paris green, tar, &c., and by soaking them in 

 solutions of salt, chloride of lime, copperas, kerosene, turpentine 

 and strychnine. These processes were found to have no effect 

 in preventing the attack or killing the wireworms. 



As regards the suggestion that wireworms may be starved 

 out by fallowing land, or by cultivating crops distasteful to 

 them, the Cornell experiments were equally unpromising. 

 Messrs. Comstock and Slingerland advise farmers not to lose 

 the use of the land for a season, and the labour necessary to 

 keep it free from vegetation, in the hope that they may starve 

 out the wireworms. The sowing of buckwheat, mustard, and 

 rape, supposed to be the special a,version of wireworms, was also 

 tried without any satisfactory results whatever. 



In the same series of experiments, kerosene oil solution made 

 of one part of oil to 20 parts of water, was sprayed on soil in 

 a cage containing 25 wireworms. The solution was made to 

 penetrate the soil by frequent sprayings. Though this process 

 was effective to some extent, it could not be profitably applied 

 on a large scale. The cost would be great, as 1,000 gallons of 

 oil would be required per acre, and this would have to be driven 

 into the soil by frequent sprayings. 



