DAMAGE CAUSED BY ANIMALS. 199 



I do, on the whole, comparatively little injury to species of sylvi- 

 cultural importance. Both the larvse and the beetles feed 011 

 foliage, gnawing away the parenchym between the ribs and the 

 veins, and leaving only the skeletons of the leaves, so that their 

 attacks are very easily distinguished from those inflicted by other 

 kinds of insects. 



As it is principally the less important kinds of forest trees 

 that suffer most from these particular enemies, trees like Aspen 

 and Saugh, which are themselves not infrequently classifiable as 

 noxious weeds, the injuries they inflict on woodlands are com- 

 paratively slight on the whole, and any real damage that is done 

 is usually confined to Alders and Willows. They are insects with 

 simple annual generation. 



The following four species comprise those of chief sylvicul- 

 tural importance : 



The Blue Alder Leaf-beetle, Chrysomela (Agalastica) alni. This 

 is a small violet or steel-blue beetle, 0*24 to 0'28 inches long, with 

 black feelers, breast, and legs. The larva is 0'4 inches long, 

 6-footed, of a blackish colour, with somewhat of a greenish lustre, 

 rather hairy, and with transverse marks across the rings on the 

 back. 



Whilst swarming during May and June as beetles, and again 

 as larvse appearing in June, this insect feeds on the leaves of the 

 Alder, and is at times very troublesome in nursery-beds. By 

 collecting the beetles after August, or during the time of swar- 

 ming in spring, when it is easier, their numerical increase may be 

 held greatly in check. 



The Red Poplar Leaf-beetle, Chrysomela (Lino) populi (vide 

 Plate I. fig. 9). The beetle is 0'4 to 0'48 inches in length ; the 

 body is blackish-blue in colour, and the elytra brick-red, with 

 black points at their extremities ; the feelers are short, com- 

 pressed, and thicken considerably towards their ends. The 

 6-footed larvse are of a dirty white, with many black dots, and 

 two white excrescences on the sides of the second and third rings. 



Both as beetle and larva, they principally feed on Poplars and 

 Aspen, but also on the foliage of Willows, when they can be 

 somewhat destructive, as they may often seriously retard the 

 development of the withes in the willow-coppices. 1 The beetles 



1 Hags of Salix purpurea and S. pentandra, together with their varieties, suffer 

 most from leaf-beetles. Trans. 



