INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 417 



Life History. — The female of the spring eankerworm oviposits in the 

 spring, before the buds of the apple trees start. The eggs are laid 

 singly or in irregular masses in crevices or under the bark scales on 

 the limbs, trunks, twigs or leaves. The young cankerworms hatch out 

 just in time to begin destroying the first young leaves. They often 

 occur in such numbers as to almost entirely defoliate the trees and 

 cause great loss. After they mature they drop to the ground and 

 pupate in a cocoon, just beneath the surface, where they hibernate 

 through the winter, and the adults appear early the next spring. There 

 is but one generation each year. The females, not having wings, must 

 crawl up the tree trunks in the spring to deposit their eggs in suitable 

 places during March and April. 



Nature of Work. — The larva 3 eat ragged holes into the leaves or 

 entirely strip the leaves from the trees and gnaw holes into the young 

 'fruit (Fig. 422). 



Distribution. — This species occurs throughout the apple-growing 

 sections of the central and northern parts of the State. 



Food Plants. — Among the many plants attacked are : apple, apricot, 

 cherry, elm, maple, pear, plum and prune. 



Control. — Inasmuch as the female is wingless, the spread of this 

 pest is not very rapid and control is not so difficult as is the case with 

 many of the orchard caterpillars. The female must crawl up the tree 

 trunk in the early spring to oviposit, and any methods adopted to 

 prevent this will reduce subsequent injury by the larvae. Bands of 

 adhesive paper or cotton around the trunks have proven effective, while 

 one of tree tanglefoot, about two inches wide, has been very satisfactory. 

 Any of these devices will cause the females to oviposit below the bands 

 and the young can be easily and readily killed with a soap wash. The 

 bands should be in place about the first of March. 



In cases where the young caterpillars are already on the trees, or 

 where the above methods have not kept them from the foliage, arsenical 

 sprays should be applied while the caterpillars are still small, as early 

 defoliation is always serious. 



Plowing and harrowing close to the trees in the fall and winter is 

 said to crush numbers of the pupae in the cocoons in the soil and aid 

 in reducing the next spring's broods. 



Natural Enemies. — The eggs are parasitized by chalcid flies and 

 preyed upon by mites, while birds, ichneumonid parasites, tachina flies 

 and predaceous bettles prey upon the larvae. 



THE OMNIVOROUS LOOPER 



Sabulodes caberata Guenee (Family Geometn<la>) 



(Tetrads wgrotata Guenee) 



(Figs. 424-428) 



Description.— The adult is a beautiful, delicate, terra-cotta-colored 

 moth with nearly or pure white ventral surface. Each of the wings 

 has two irregular dusky transverse bands on the upper surface, one on 

 each side of the middle. The margin, near the middle, is extended in 

 a blunt projection. The under surface is creamy-white, peppered with 

 many small dark spots. The abdomen is also sparsely covered with 



27—130(14 



