158 



INSECTS. 



SECTION TRIMERA. 



Two families, of which one only need be noticed here, are included in this 

 section. The Coccinellidce, or lady-birds are so familiar to everyone that it is quite 

 unnecessary to describe their general appearance. They are resembled in shape 

 by some other beetles, but in such cases the lady-birds may be distinguished by their 

 three-jointed tarsi, clubbed antennae, and the hatchet-shaped terminal joint of their 

 palpi. These charming little insects have always been held in much respect, as the 

 different names given to them testify, and it is well that it should be so. For 

 while the species of a few genera (Epilachna, Lasia) are herbivorous in their 

 habits, the great majority live — especially in the larval state — upon green-fly and 

 plant-lice, and, by keeping these noxious insects in check, perform a useful service 

 to man. The lady-birds are found in nearly all parts of the world, and over a 



6 



LADY-BIRDS. 



1, Micraspis duodecimpunctata (nat. size and enlarged) ; 2, Coccinella septevipunctata ; 3, Larva (enlarged) ; 4, 

 C. impustulata ; 5, 0. bipunctata and dark variety ; 6, Chilocorus bipustidatus. 



thousand different species are known. Among several species occurring in Britain 

 the two commonest are, perhaps, the large seven-spotted Coccinella septempuncta 

 and the small two-spotted C. bipunctata. The latter varies in colour to a 

 great extent, so that between the typical form with red elytra marked with two 

 black spots, and others in which the elytra are entirely black, one meets with 

 almost every intermediate condition. The larvae of these species may often be 

 seen walking about on leaves that are infested with green-fly. They may be 

 recognised by their slate-blue colour, marked with some yellow dots, and by the 

 greed with which they devour the aphides. The larvae, when about five or six 

 weeks old, are ready to pupate. Fixing themselves by the tail-end to a leaf, they 

 cast their skin, and the pupae, resting upon the cast-off larval skin, remain attached 

 to the leaf. The beetles emerge about eight days later, so that the whole course of 

 development from the egg to the perfect insect is completed in less than a couple 

 of months. 



C. J. GAHAN. 



