126 APPLIED ENTOMOLOGY 



Control. — The adult beetles can be killed by spraying the leaves with arsenate 

 of lead using 3 or 4 lb. of the paste in 50 gal. of Bordeaux mixture, just before 

 or as soon as the first signs of feeding appear, and again after 10 days. Great 

 care must be taken, however, to do this work thoroughly, as the beetles avoid 

 sprayed foliage. The beetles may also be jarred off the vines, particularly on 

 warm days, onto sticky boards, fly paper, or sheets or some other type of catcher 

 placed beneath the plants, whence they can be gathered and destroyed. The 

 pupae are located within a few inches of the top of the ground and are mostly 

 within two or three; feet of the vine. In this state of their existence they are easily 

 destroyed by any thorough breaking up of the soil where they are, and this is 

 taken advantage of by throwing up the earth on each side of the vines in the fall 

 to form a ridge. Most of the larvae work up into this to pupate, the following 

 spring, and while the insects are in the pupa stage there this ridge should be hoed ■ 

 away by a horse-hoe and by hand, or by the latter alone for small areas. Later 

 cultivation will reach some of those escaping the first treatment which in the 

 grape belt named is usually about the middle of June. 



The Calif ornian species is a Httle smaller than the one just described, and jet- 

 black or brown. Its habits and methods for controlling it are about the same as 

 with the eastern pest. 



The Elm Leaf Beetle {Galerucella luteola Muls.). — This European insect 

 appears to have reached this country at Baltimore about 1834 and has now spread 

 through most of the New England and Middle Atlantic States and westward 

 nearly to the Mississippi River, though not everywhere present within these 

 limits. 



The adult beetle (Fig. 118) is about a quarter of an inch long, dull yellow in 

 color, with black spots on the head and pronotum, a black band near the outside 

 of each elytron, and a short streak at the base of each, nearer the middle. The 

 beetles winter over in protected places and in the spring the dull yellow has 

 changed to an olive-green (Fig. 118). They fly to the elm trees when the foliage 

 develops, and feed, eating irregular holes in the leaves and from time to time lay- 

 ing yellow eggs on the underside of the leaves, usually about 25 in number and 

 nearly always in two rows, side by side (Fig. 1,18). The eggs hatch after about a 

 week and the tiny yellow and black grubs feed for about 3 weeks, working on the 

 under surface and leaving the upper epidermis of the leaf unbroken. When full- 

 grown (Fig. 118) and about half an inch long they crawl down the tree to the 

 trunk and pupate for from 1 to over 3 weeks according to the temperature, either in 

 crevices of the bark on the lower part of the trunk or on the ground near the foot 

 of the tree (Fig. 118). In the more northerly states the larvae feed during June. 

 Farther south they begin in May and a second generation feeds during the late 

 summer or early fall. The European elms are most severely injured by this 

 insect but other species often suffer greatly. 



Control. — ^Spraying the trees about the time the eggs are laid, i.e., soon after 

 the leaves are fully grown, with arsenate of lead is the usual method of control. 

 The strength of the material should be increased above the standard to 5 lb. of the 

 paste, to obtain good results, and it should be kept in mind that as the grubs do 

 not feed on nor reach the upper surface of the leaves, the spray shoald be directed 

 as far as possible onto the under surfaces. 



