THE LINDEN LEAF-BEETLE. 479 



9. The Linden leaf-beetle. 



Chrysomela acalaris Leconte. 



Order Coleoptera ; family Chrysomelid^. 



Injuring the leaves, a stout-bodied beetle with silvery wing-covers spotted with 

 green, laying its eggs on the leaves in the spring, from which fat, thick-bodied white 

 grubs develop, with a lateral row of large black dots, and which also prey on the 

 leaves. 



While this beautiful and abuudant beetle is more 

 common on the alder, it also occurs on the lime-tree 

 and elm. They may be found on these trees in April, 

 May, and June, and a second brood in September 

 and October. We have taken them in coitu on the 

 alder in Maine the middle of May. The grubs are 

 hatched from eggs laid by the beetles on the leaves 

 in spring and come to their growth towards the end 

 of June in Massachusetts, according to Harris, who fig. ns.—chrysomeia 

 believes that they go into the ground to turn to pupse. scaiaris. smith da. 



Since the foregoing account was prepared, we have observed this 

 beetle in all its stages. At Brunswick, Me., during July and August, 

 1881, it was very abundant on the numerous linden trees in the campus 

 of Bowdoin College, eating rounded holes in the leaves and causing 

 them to turn yellow and unsightly, as if to prematurely fall. Nearly 

 every tree and, in some cases, nearly every leaf on a tree was infested 

 by the disgusting pale grubs, while scattered patches of eggs occurred 

 on the under side of the leaves; and during the first to last of August 

 the beetles were found not uncommonly upon the leaves. The trees 

 could be protected by showering the leaves with London purple in 

 water when the grubs first appear late in June. From these specimens 

 the following descriptions were drawn up : 



Egg. — Rather large, oval cylindrical, yellow, several together attached by one end ; 

 about LS™"" in length. 



Larva. — Body very thick, curved up like that of the grub of the Colorado potato- 

 beetle, being much swollen behind the thoracic segmeuts, while the tip of the abdo- 

 men is curved down. Head honey-yellow, darker over the jaws ; antennae bluish, 

 except at base ; eyes black. Prothoracic shield blackish in the young before the last 

 molt ; in full-grown individuals not all black, but pale, with four irregularly square 

 black spots. Body behind dirty white with a row of dorsal and lateral dusky spots. 

 Legs pale, spotted with black at the joints. A pair of meso-thoracic spiracles, and 

 eight pairs of smaller abdominal ones. Low down, on the sides of the second and 

 third thoracic segments a curvilinear black spot. Length. 8 to 9™™. 



Pupa. — Body jiure white ; prothoracic shield with long scattered hairs around the 

 edge and in two groups on the back ; antenns© curving around between the eyes and 

 jaws, and with the ends resting on the tips of the elytra. The insect undoubtedly 

 descends into the earth to pupate. 



The heHle. — Head, prothorax, and under side of body dark coppery green, with scat- 

 tered pits. Antennae, palpi, and legs pale pitchy yellow; elytra coppery green and 

 whitish, the green forming a broad median stripe, sending prolongations outwards 

 toward the m'ddle of the elytra, the first pair of branches nearly parallel to the band, 



