WIREWORMS ATTACKING CEEEAL AND FORAGE CROPS. 13 



The beetle of this species is about one-half inch long, quite slender, 

 and jet black in color. The wireworm is very similar to the inflated 

 wireworm. 



Early in April, 1910, our attention was called to a series of severe 

 wireworm outbreaks in the region above outlined. On the 5th of the 

 month the farm of a Mr. Dunnigan, at Connell, Wash., was visited. He 

 w&s at that time reseeding 1,800 acres of wheat which had been killed 

 out by these wireworms. From Connell we proceeded to Govan, Wash., 

 and here we found the wireworms also doing considerable damage. 

 In a fallow field that had been ruined by wireworms when in oats in 

 1909 we found them in enormous numbers. These wireworms when 

 in the field are usually to be found between the dust mulch and the 

 moister earth below. This species is more or less destructive through- 

 out its range. During 1910 reports of severe outbreaks were received 

 from eight wheat-receiving stations in the States of Washington and 

 Idaho. 



LIFE HISTORY. 



This beetle is about during June and July, at which time it 

 deposits its eggs in wheat fields, weedy fallow fields, and volunteer 

 wheat on fallow land. The eggs are undoubtedly laid underground 

 by the female burrowing into the soft earth, as many adults were col- 

 lected in the fields at a depth of from 5 to 8 inches below the surface 

 which were not in pupal cells. Mr. J. E. Graf, of the Bureau of 

 Entomology, has found this to be the case with the sugar-beet wire- 

 worm. 2 The young larvse are to be found in the soil during August 

 and the remainder of the summer, but their depredations are not 

 noticeable at this time, as, in the region where the species occurs, 

 wheat is the only extensively grown crop. The young wireworms 

 pass their first winter in the soil at a depth of from 12 to 20 inches 

 below the surface. The following spring and summer they spend in 

 the summer fallow and are not noticed. Their second winter they 

 again hibernate as wireworms, and in the spring of their third year, 

 the field being now planted to wheat, they turn their attention to the 

 seed and young plants, and it is at this time that their depredations 

 are so startlingly noticeable. They feed during late March, April, 

 and May, and early in June burrow to from 4 to 8 inches below the 

 surface, making small oval cells, in which the very fat larvae lie in 

 an inactive condition during June, July, and early August, when 

 they pupate and the adults emerge from the pupal skins the middle 

 of that month, but remain in the pupal cells the remainder of that 

 summer and the ensuing winter, not emerging from the ground until 

 the fourth spring from that in which the eggs were laid. 



2 Graf, John E. A Preliminary Report on the Sugar-Beet Wireworm. U. S, Dept„ 

 Agr., Bur. Ent., Bui. 123, p. 18, Feb. 28, 1914. 



