59 



Plagiodera lapponica, Linn., is more elongated and flattened than species of the 

 genus Chrysomela. It is one-fourth of an inch long ; black ; the elytra, orange with 

 black spots, and is found upon alders and willows. The larva is of a dingy yellowish- 

 white colour, with black head and legs. Upon the sides and back are rows of small 

 dusky tubercles ; the outer-dorsal rows being more distinct and capable of emitting from 

 their tips a milky, pungent fluid. 



P. Scripta, Fab., a very closely allied species, (by some held to be but a variety of 

 the last) has proved itself a very destructive insect in the Western States ; especially in 

 the prairie regions, where it has become a grievous pest on account of its depredations 

 on the cottonwood. This tree is grown very extensively as a shade and ornamental tree, 

 and for fuel, and vast groves are stated to have been utterly destroyed by repeated de- 

 foliations. The eggs are laid in clusters, of from ten to one hundred, on the young leaves 

 in the spring and quickly develop. There are two or three broods during the summer. 



Monocesta coryli, Say., (corylus being the latin for a hazel, or filbert tree,) is known 

 in the United States as the Great Elm-leaf Beetle, and is occasionaly very destructive 

 to the red or slippery elm. Its eggs are laid on the under side of the leaves in J une, and 

 from them issue in a few days brown, or yellowish brown larvae, which, growing rapidly, 

 " eat the leaves into rags." About the end of July they enter the ground and pupate. 



The genus Diabrotica contains a number of species, of which D. vittata, Fab., the 

 Striped Cucumber Beetle, is a well-known gardener's pest. It was well figured and 

 described in the Report of 1878. The little lemon-yellow bettle (Fig. 70), 

 with a black head and three black stripes on the wing-covers, makes its appear- 

 ance as cucumbers, squashes and melons commence to show above ground. It 

 feeds upon the young leaves, and at the same time deposits its eggs near the roots 

 of the young vines. From these hatch out slender white grubs having small 

 brownish heads, and slim, pale-brown thoracic legs. Burrowing into the 

 stems just below the surface of the ground (the plants being thereby weakened 

 and often destroyed), the larva reaches maturity in about a month from the deposition of 

 the egg, and is then one-third of an inch long. Leaving the plant it pupates in a little 

 cell in the earth, and emerges after a couple of weeks as a beetle, which feeds upon the 

 young shoots and buds. There are two or three broods during the season, the last 

 remaining in the ground all winter as pupae. An effective, and not expensive, method of 

 protecting the young plants is to cover them with wooden frames having gauze tops. 



A larger but less common species is that known as D. 12-punctata, Oliv., or Twelve- 

 Spotted Diabrotica, which derives its name from twelve black spots upon the elytra 

 (Fig. 71). It is stated by Packard to be injurious to the leaves of the dahlia. 



Within the past few years a beetle belonging to this genus, and closely 

 allied to our cucumber beetle, has become noted in Illinois, Missouri and other 

 Western States as a corn pest. The larvae of D. longicornis, Say, the Long- 

 horned Diabrotica, are very similar in size and appearance to those of our 

 cucumber beetle, and feed on and in the roots of the young corn-plants, 

 causing them to wither and die. The beetle is of a uniform pale greenish- 

 yellow, without any markings. The application of lime and ashes around the young corn 

 is proposed as a preventative. 



Several species of the genera Galeruca and Galerucella are found in Canada, they are 

 similar in form to Diabrotica, but, generally a little smaller and of a darker colour. 

 Galeruca rufosanguinea, Say, is well described by its specific name which means blood- 

 red. It is one-fifth of an inch long and is found upon various trees. Last J une it was 

 abundant on choke-cherry. 



Galerucella marginella, Kirby, has been described by Packard as found in all its- 

 stages upon Myrica gale* in August. The larva is shining black and the beetle closely 

 resembles the following species, except in being darker. 



G. xanthomelina, Schr., (the imported elm beetle) is said to feed upon the elm in 

 such numbers as often to wholly defoliate the trees. In 1879, the elms of Newburg, 1ST. Y., 

 a town celebrated for its fine avenues of this handsome tree, were almost stripped by these 

 beetles. The larvae are thick, cylindrical, blackish grubs, producing greyish-yellow beetles 

 distinguished by three black dots on the thorax, and a black stripe on the outer edge of the 

 elytron. 



