rnopcirrr ofJB DIVISION OF 



FORESTRY 



COLLEGE OF M AGRICULTURE 

 OF CALIFORNIA 



WIREWORMS AND WHITE GRUBS. 



Several kinds of garden and field crops are injured each year 

 in New Hampshire by wireworms, or by white grubs, or by 

 both. The two are here described together, not because they 

 are nearly related but because the manner of work is similar 

 and the means of avoiding injury is the same for each. 



CHARACTERISTICS OF WIREWORMS. 



While there are several common species of wireworms in New 

 Hamphsire, all are much alike. They are slender, dark brown 

 worms, an inch or so long, and of a distinctly wiry appearance. 

 The three pairs of legs are small, and are near the front end of 

 the body. There are no legs on the middle or hind end. 



They work always beneath the surface of the ground, gnawing 

 the surface of the roots of plants or frequently boring into them. 

 In potatoes, half a dozen worms' may bore into a single tuber, 

 and often when potatoes are dug one or more worms will be 

 found within or protruding from the surface. 



The adults of wireworms are slender, brown beetles, which 

 have the characteristic habit of righting themselves, when 

 placed on their backs, by snapping themselves sharply back- 

 ward so as to throw the body an inch or two into the air. Their 

 common name is snapping beetles or click beetles. 



The beetles lay eggs on the ground. These eggs hatch into 

 very small wireworms. The latter feed and grow, and finally 

 change to a resting stage or pupa. From this the adult beetle 

 emerges. This is the life round for all of them. All the stages 

 except that of the beetle are passed in the soil. The life of the 

 adult beetle lasts but a few weeks. That of the worm stage lasts 

 for two or three years a fact which has an important bearing 

 on the nature of the injury done by them, as will be shown 

 below. 



The normal breeding-place of wireworms is in sod ground. 

 Grass-roots or the roots of weeds form their accustomed diet. 

 Hence we may expect to find many of them in land that has 

 been in sod for several years. Ordinarily their presence in such 

 fields passes unnoticed, because the ground is so full of roots 

 that the feeding is not appreciable. 



The injury to garden or field crops comes about when sod 

 land is broken up and planted to crops. Since the worms require 

 two or more years to mature, many half-grown worms are left 



