126 



INSECTS INJURIOUS TO VEGETABLES 



increasing its range, and as it has developed an unusual fond- 

 ness for sugar-beet it will in time become a beet pest of great" 

 importance. It has evidently been introduced on the Pacific 

 Coast and has been found destructive as far eastward as 

 Michigan and Nebraska, and has done considerable injury in 

 other localities, including Canada where it was recently very 

 destructive. It is cousin to the native garden webworm, which 

 it resembles in general form. It is, however, darker and about 



Fig. 80.— Beet webwo.m. a. Moth, twice natural size; b, larva, less enlarged; e. upper 

 surface of first proleg segment of larva; d. side view of same; c, d. more enlarged- 

 (After Insect Life.) 



one-fourth larger. Fully expanded the wings measure nearly 

 an inch, and are purplish brown in color, with darker and paler 

 bands, as shown (fig. 80,0). The hibernating caterpillars make 

 a burrow beneath the surface of the ground and construct a 

 cocoon about three times as long as themselves. A similar but 

 shorter cocoon is made by the midsummer brood. 



A favorite wild food plant of this species has been observed 

 — the pigweed or careless weed (Amaranthus) — and injury to 

 sugar-beet has been observed in many cases where the ground 

 was allowed to run to the wild plant. 



Remedies. — The destruction of this and other weeds might 

 in time lead to comparative immunity from the attack of the 

 webworm. Paris green or other arsenical sprayed several times 

 over the infested plants will also compass its destruction. 



