6 BULLETIN 156, U. S. DEPARTMENT OF AGRICULTURE. 



the rearing cages on August 26 and adults emerged as late as the 

 middle of September at Grimsby. Ontario, Canada. 1 



The pupal stage usually lasts from 15 to 19 days. One specimen 

 collected at Watertown, Wis., by Mr. Dayis pupated on August 8 

 and the adult emerged August 19. A specimen collected at Bridge- 

 port. X. Y., pupated on August 12 and emerged September 1. Other 

 specimens collected July 25 at the latter place became adult Au- 

 gust 12. 



The pupal chamber consists of an oral cell, the long axis of which 

 is perpendicular, located at a uniform depth of about 5 inches be- 

 low the surface of the soil. The dust mulch in the case under dis- 

 cussion was 4 inches deep and the pupal cells were about 1 inch 

 deeper than cultiyation in the moist, firm soil. The pupa stands 

 erect in the cell with the head upward, the laryal exuyium being 

 at the bottom of the cell. 



The adult evidently passes the remainder of the summer in the 

 pupal cell, in which it also later hibernates. Matured adults were 

 found in these cells in the fields at Bridgeport, X. Y., as late as 

 September 15, and in our rearing cages adults passed the winter 

 without feeding or drinking. 



Three distinct generations of larvae were collected in the field in 

 the summer of 1913 — full-grown larvae about to pupate, half-grown 

 larvae, and larvae about one-fourth inch long — actively feeding on 

 the corn. We have now in the laboratory, subject to outdoor tem- 

 perature, two distinct generations of larvae collected in the summer 

 of 1913. The first generation — that is, the largest larvae collected — all 

 transformed to adults during August. Mr. Pettit and several others 

 have made similar observations, and there is no doubt that this 

 species, at least in the northeastern United States, spends three years 

 as a larva. 



FOOD PLANTS. 



Agriotes mancus was observed at Bridgeport, X. Y., feeding upon 

 corn seed and roots, potato tubers, wheat roots, carrots, and the un- 

 derground stems of string beans: a single specimen was also found 

 within the stem of the common field mushroom {Agarieus camves- 

 tris). Other writers have found it attacking the cucumber, turnip. 

 and cabbage. Mr. Theo. Pergancle, of this bureau, records 2 a larva 

 of this species feeding on the larva of a lamellicorn beetle in one of 

 his rearing cages. The writer is of the opinion, however, that nor- 

 mally this species is not predaceous. 



1 Pettit, J. Description of the wheat wireworm (Agriotes mancus Sayi. In Canad. 

 Ent., v. 4, No. 1, p. 3-6. fig. 1, January, 1872. 



2 P. S. Dept. Agr., Div. Ent., Notes, v. 4, No. 2795, Oct. 5, 1882. 



