54 



In shape they are oval or oblong, with numerous short and robust species. 

 The eyes are prominent, and the antennae comparatively short. The larvae of the larger 

 species are found feeding upon leaves, and are stout, cylindrical, fleshy grubs, with 

 rhoracic legs. They are frequently highly coloured, but the majority are not pleasing 

 >bjects, and many species cover themselves with a coat of the excreted fragments of 

 devoured leaves, which gives them a filthy appearance. The larvae of many small species 

 are little flattened worms mining in the leaves, that is they feed upon the inner substance 

 of the leaf, leaving the upper and lower surfaces untouched, and making disfiguring 

 blotches, such as are also caused by larvae belonging to other orders. 



The beetles are frequently very handsome ; resplendent with gay colours and bright 

 metalic lustres, or ornamented with quaint and striking markings. About five hundred 

 species are recorded from the United States and Canada, and in both countries con- 

 siderable damage has been inflicted by different species. 



Descriptions of several species and accounts of their operations have already been 

 given in previous Reports, but as they are scattered through the different numbers, and 

 perhaps inaccessible to some who may receive this, a brief review of them (as they are 

 reached) may not be superfluous. 



The genus Donacia, with which the family commences, approaches in some respects 

 to the Cerambycidae, or "long-horned" beetles, and serves as a partial link between that 

 family and the Chrysomelidae. The beetles of this genus differ from those of most other 

 genera in having longer and more cylindrical bodies and longer antennae. The larvae are 

 said to live in the stems of water-plants, and to make a leathery cocoon in the earth 

 before transforming. I have often found empty cocoons of such nature attached to roots 

 of aquatic plants. 



Donacia proxima, Kirby, probably our largest species is a fine beetle of a deep 

 bluish-black colour above, while the under surface is silvery- white, being densely covered 

 with short hairs. The thighs of the hinder legs (as in many of the species) are swollen, 

 and bear a short tooth. The beetles are found on hot summer days upon the floating 

 leaves of the water-lilies, where they mate and sport in the bright sunshine, which gives 

 to them an added lustre. 



Donacia subtilis, Kunze, our most common species is very abundant in June and 

 July upon rushes and sedges. D. cequalis, Say, may be found towards the end of July, 

 feeding upon the leaves of Sagittariae. D. pubescens, Lee., owing to a coat of yellowish 

 hair, lacks the lustre of the previous species. 



Hcemonia nigricornis, Kirby (Melsheimeri, Lac), is a smaller and more delicate 

 beetle, of a yellowish colour, and having the tip of the wing-cover prolonged in a sharp 

 spine. It occurs somewhat abundantly in the latter part of June upon the leaves of 

 Potomageton natans, where it is, from its colour, very inconspicuous. It seems equally 

 at home in the water as in the air. I have seen, and captured, specimens paired beneath 

 the surface of the water, while other individuals, also completely submerged, were feed- 

 ing upon the epidermis of the leaves. It walks easily upon the surface from plant to 

 plant, and has the habit of running a little distance upon the water and taking flight 

 therefrom, instead of directly from the leaf upon which it has been. 



Leaving the aquatic species, we come to a small, slender beetle, very common upon 

 flowers in spring and early summer. This insect, Orsodachna Childreni, Kirby, varies 

 remarkably in coloration, and several of its varieties were formerly described and known 

 as separate species. It ranges in colour from a tawny-yellow to black, and one well- 

 marked variety has the head and elytra black, while the thorax is red. 



Syneta tripla, Say, is a pretty reddish or yellowish beetle, found in May or June 

 feeding upon the leaves of beech, elm. etc. 



Lema trilineata, Oliv., is about as long as the last species, but is broader 

 and more stoutly built. It is an orange-red beetle, with black eyes, feet 

 and antennae. There are also two black spots upon the thorax, and 

 £he elytra bear three broad, black stripes, which give to the beetle its 

 specific name. (See Fig. 56.) It is found abundantly upon potato plants 

 throughout Canada, and is popularly known as the " Three-lined potato 

 beetle." The eggs are deposited upon the under side of the leaf Fig. 56. 



