570 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



Canker Worms * 



Since the early colonial 

 days Canker Worms have 

 been among the best-known 

 insect pests of the apple 

 orchard, but they are 

 general feeders and attack several orchard 

 and shade trees. According to Dr. W. E. 

 Britton they " seem to have a preference 

 for the foliage of apple, elm, chestnut, pear, 

 oak, hickory, box-elder, and maple, in about 

 the order named," and cherry and plum 

 are recorded by others. The canker worms 

 are among the most common of the " loopers " 

 or " measuring worms," and are the larvae 

 of two nearly related species of moths, very 

 similar in both appearance and habits. The 

 larvae defoliate the trees in early spring, 

 particularly in old sod orchards which have 

 not been cultivated or sprayed. 



The Spring Canker Worm f 



This species is so called from the fact that 

 its eggs are laid in the early spring instead of 

 in the fall, as are those of the other species. 

 It occurs from Maine to Iow r a and southward 

 to Texas, and in Colorado and California, but 

 has not been rep rted on the Atlantic Coast 

 south of New Jersey according to Coquillet. It 



* Family Geometridce. See D. W. Coquillet, Circular 

 9, Div. Ent., U. S. Dept. Agr.; W. E. Britton, Bien- 

 nial Report Conn., Agr. Exp. Sta., 1907-08, p. 777; 

 A. L. Quaintance, Bulletin 68, Part II, Bureau of 

 Entomology, U. S. Dept. Agr. 



f Paleacrita vernata Peck. Family Geometridce. 



FIG. 422. Canker 

 worms dropping 

 from foliage in 

 characterise at- 

 titudes. (After 

 Bailey.) 



