INJURIOUS AND BENEFICIAL INSECTS 



21 



Fig. 29 Elm leaf beetle, 

 adult (reduced from How- 

 ard, U. S. dep't agr., Year- 

 book 1895) 



turn brown. The yellowish, black striped beetles, about J inch 



long, appear in early spring and lay eggs in May. The grubs feed 



in June, changing to yellow pupae the latter part of the month. 



A second brood occurs in July and extends 



into September. Known to occur in this 



state on Long Island, in the Hudson river 



valley north to Schuylerville, and in a few 



places in western central New York. This 



pest prefers European elms, but when 



numerous will seriously injure American, 



elms. 



Treatment: spray the young foliage of in- 

 fested trees with poison early in May to kill 



the beetles. The spray must he throion on 



the under surface of the leaf in order to kill 



the grubs. Kill larvae and pupae on and 



near trunks of the trees either with hot water, with kerosene 



emulsion or by sweeping up and burning. 

 37 Spiny elm caterpillar (Euvanessa antiopa). Large 



black, red marked, spiny caterpillars 

 about 2 inches long may frequently be 

 seen in June feeding on the leaves of elm, 

 willow and several other trees. The 

 parent butterfly is a handsome purplish 

 insect with yellow bordered wings. There 

 are two annual generations in New York 

 state. 



Treatment: remove the gregarious cater- 

 pillars and crush them or spray the in- 

 fested limbs with poison. 



38 Elm bark louse (Go ssyparia 

 u 1 m i). The adult females in June appear 

 like clusters of small lichens on the under 

 side of the smaller limbs of European 

 elms. The young emerge in July. This in- 

 sect appears to be generally distributed in 



the Hudson river valley, and will probably soon make its way to 



Fig. 30 Spiny elm cater 

 pillar (original) 



