ENGLISH: ILLINOIS TREES: THEIR INSECT ENEMIES 



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Fig. 18. — Elm leaf beetle: .4, eggs; B, larva; C, pupa; D, adult. Both 

 larva and adult feed on foliage. The eggs are yellow and spindle shaped ; the 

 larva is spiny and almost black; the adult, about one-fourth inch long, has 

 a yellowish to green body and yellowish legs and antennae. 



on the under sides of the leaves of an elm tree about the time 

 the leaves become full grown. When through feeding, the grub 

 drops or crawls to the ground near the base of the tree, pupates, 

 and transforms to the adult stage to start another generation. 

 The adults hibernate in barns, sheds, and dwellings, where, if 

 present in large numbers, they sometimes become a nuisance. 

 Each beetle is about one-fourth inch long; it has yellow legs 

 and antennae and a yellowish to green body. It chews small holes 

 in the foliage. The female beetle lays 400 to 800 eggs, which 

 hatch in about a week. 



Control Measure 1 or 2 (end of circular) about the time 

 leaves are grown or as soon as damage is observed. 



European Elm Scale, Gossyparia spuria (Mod.), fig. 19. — 

 Although inconspicuous, like other scale insects, the European 

 elm scale occurs in dense populations and sucks great quantities 

 of sap from any tree it infests. Some of the sap is secreted as 

 honeydew, on which a sooty mold may grow. 



The immature scale, which overwinters on a limb or branch 

 or in a crotch of an elm, is about one-tenth inch long, oval, red- 

 dish-brown in color, and has a white fringe. The male completes 

 development in a white cocoon. The female changes little from 

 the overwintering form. In early summer, she lays eggs on a 

 limb or branch. Hatching in an hour or so, the young scales 

 move in great numbers to the under sides of nearby leaves, 



