84 



The fourth, or Trimerous section contains but few families, of which 

 it is only necessary for us to name but one : 



Coccinnellidae, the lady-birds, or plant-louse beetles. 



In order to aid the reader as far as possible in his efforts to deter- 

 mine species from larval characters, I present the following remarks 

 in reference to the larvae of families containing injurious species: 



The larvae of the leaf-chafers, and stag-beetles (Lucanidae, Mclolonthi- 

 dae,Rutelidae and Cetoniidae) are thick, fleshy grubs, with a distinct head, 

 which is usually dark or brown, with strong jaws. As a general rule 

 they are more or less enlarged toward the hinder extremity, the last 

 segment usually the largest; the back is generally wrinkled transversely. 

 They have but six feet, situated on the first three segments behind 

 the head ; are generally more or less curved or bent, and lie upon one 

 side, in which position they feed. As a matter of course, they and 

 all other larvae vary according to the size of the species and 

 the age at which they are observed. Some, as those of the stag 

 beetles, are found in rotten or decayed wood, and are seldom injurious; 

 others, as those of the May-beetles, June-bugs, vine-chafers, etc., reside 

 in the ground, living upon the roots of grasses and other plants, some- 

 times doing immense injury to meadows. 



The common "white grub" is an example of this group. 



Here I must warn the reader against making a mistake in suppos- 

 ing that no other larvae except these have this form. These char- 

 acters are mentioned simply to inform him that when he finds a 

 larva of this kind feeding 'upon the roots of grass, shrubs, straw- 

 berries, etc., in all probability it belongs to this group, and thus assist 

 him in his search for the species. 



The larvae of the Saw-horned wood-beetles (Buprestidae) are some- 

 times called hammer-headed larvae, from the great development of 

 the first segment. 



The whole body is usually slightly flattened, especially the segment 

 immediatelv behind the head, which is much expanded laterally, 

 sometimes to twice the width of the head and of the posterior seg- 

 ments ; the latter being more rounded than the first and nearly equal 

 in size. They are footless grubs, and are found boring into timber, 

 often doing much injury to fruit and other trees. The flat-headed 

 borer of the apple tree (Chrysobothrus femoratits) is a familiar ex- 

 ample. 



There are other wood-boring larvae, which somewhat closely re- 

 semble the Buprestian larvae. These belong chiefly to the Lamiinae, 

 a sub-family of the Oerambycidae, or long-horned wood-borers. They 

 are rather more cylindrical than the Buprestians, and they are gener- 

 ally nearly of a cylindrical form. The round-headed apple-borer 

 Saperda Candida or bivittata is an example of this sub-family. 



The larva of the other long-homed wood-boiers, at least those of the 

 sub-families Prioninae and Ocrambyeinae are similar in form, but have 

 six minute 1< gs on the first three segments. Belonging to the latter 

 is the locust-borer (Gtytus robiuiae). In all these wood-borers the head 

 is smaller than the first segment. 



The larvae of the Elaters, Snap-jacks or Snapping-beetles, are 

 elongate, cylindrical worms, generally quite slender, with the divi- 

 sions between the segments not strongly marked ; six small legs on 



