AND 01 MER INJURIOUS INSECTS OF I907 AND I908. 



107 



with a fine web, thus in a measure preventing the successful coating 

 of the leaf with poison. Yet an application of four to six pounds of 

 arsenate of lead (Disparene) in a hundred gallons of water, upon the 

 foliage not so covered, which will be later attacked, would bring 

 about the desired result. Further, a spray applied when the worms 

 are newly hatched will be effective before they have begun to spin web. 

 The simpler method above referred to is to break off the "weV* or 

 nest zvhen first observed, before any serious injury has been done, and 

 burn it zmth the contained zvorms, or crush them under foot. The 

 only obstacle, and one which can be readily overcome, to the suc- 

 cessful working of this method, is the fact that their work may escape 

 observation until a small tree is nearly defoliated, or neglect to destroy 

 the nests when first seen. It is to be noted that their nests are de- 

 serted in the fall ; hence destroying these at this time is not effective. 



ITS OCCURRENCE AND FOOD PLANTS IN I907. 



While observed in various parts of the state last summer, its 

 work was most apparently localized in the southwestern corner of 

 Hennepin County, along the line of the Great Northern railroad, in 

 the vicinity of Lake Minnetonka. Going from Minneapolis to Mound 

 on this road, one curiously enough first notices their unsightly nests in 

 the neighborhood of Spring Park, and these become more abundant 

 as Mound is approached. In the vicinity of the latter town, within a 

 radius of about five miles, it has been exceedingly abundant the past 

 two summers and evidences of its work are on every side. It has at- 

 tacked pig-nut, bass wood, elm, maple, birch, box elder, plum, apple, 

 lilac, sumac, wild gooseberry, etc. In fact, it appears to be a general 

 feeder though it shows a marked predilection for pig-nut. 



Fig. 50. The Fall Web Worm: «, dark covered larva from the side; c, the same 

 from above; 6, light covered larva; ri, pupa from below, e, same from side. Bureau 

 of Eatomology, U. S. Dept. Agrl . 



