THE CANADIAN ENTOMOLOGIST. 67 



THE COLEOPTERA OF CANADA. 



BY H. F. WICKHAM, IOWA CITY, IOWA. 



XV. The Chrysomelid/E of Ontario and Quebec. 



The above family is of immense extent and attains, in the tropics, a 

 considerable development in the size of its members, though not equalling 

 in this respect its wood-eating neighbours^ the Cerambycidas. Towards 

 the north, many groups fade out entirely and the large or gaily-coloured 

 species decrease in number. Nevertheless, the representation in Canada 

 is quite considerable, and since many of the species are closely allied and 

 separate with some difficulty, while tables of genera are widely scattered, 

 or, in many cases, not readily accessible, it has been deemed worth while 

 to bring together the salient characters by means of which the collector 

 in Eastern Canada may hope to identify his captures. 



According to the classification followed in this country, the members 

 of the family agree in these points : The tarsi are broad, spongy beneath, 

 the fourth and fifth joints being so closely anchylosed as to give the 

 appearance of but four joints ; the head has the front small and oblique, 

 the antennae are moderate or short and not inserted upon frontal 

 prominences. The prothorax is most frequently margined and the tibial 

 spurs usually wanting. A few exceptions occur to each of the above 

 characters, but most of the Chrysomelidaj may easily be recognized at 

 sight by their resemblance to a few common types, such as Donacia, 

 Cryptocephalus, Chrysochus, Chrysomela, Ga/eruca, Haltica, Micro- 

 rhopala and Cassida. There is, however, _no uniformity of family 

 habitus, as many of the Cassidini are extremely broad and flattened, while 

 the Cryptocephalini are occasionally nearly globular. 



AH of the Chrysomelidje may be said to be vegetable feeders, and 

 most of them are to be found in every stage upon the leaves, in the stems 

 or about the roots of their food-plants. The larvae are not of a very 

 uniform type of structure, but are modified to suit their particular habits 

 of life. Most of those that feed freely upon the surface of leaves are of 

 rather heavy, subcylindrical or subglobular form and slow in movement. 

 A good example of this type is to be seen in the young of the Colorado 

 potato-beetle. Other leaf-eating larvse, such as those of Coptocycla and 

 its allies, are flattened and curiously armed with spines or covered with a 

 coat of their own excrement. The leaf-mining or stem-boring kinds are 

 usually of more slender, elongate shape and without the conspicuous 



