ENTOMOLOGY 



FIG. 61. 



em 



Left hind leg of Bittacus. c, coxa 

 genuina; em, epimeron; es, episternum; f, 

 femur; m, meron; t, trochanter. 



dragon flies form a basket for catching the prey on the wing. 

 Modifications of the front legs for the purpose of grasping 

 occur in many insects, as the terrestrial families Mantidae (C) 

 and Reduviidae and the aquatic families Belostomidse and 



Naucoridse (D). Swim- 

 ming species present special 

 adaptations of the legs (Fig. 

 228), as described in the 

 chapter on aquatic insects. 

 In digging insects, the fore 

 legs are expanded to form 

 shovel-like organs, notably 

 in the mole-cricket (Fig. 62, 

 ), in which the fore tibia 

 has some resemblance to the 

 human hand, while th tarsus and tibia are remarkably adapted 

 for cutting roots, after the manner of shears. The Scara- 

 bseidae have fossorial legs, the anterior tarsi of which are in 

 some genera reduced (F) or absent; they are rudimentary in 

 the female (G) of Phanceus carnifex and absent in the male 

 (//), and absent in both sexes of Deltochilum. Though 

 females of Phanceus lose their front tarsi by digging, the de- 

 generate condition of these organs cannot be attributed to the 

 inheritance of a mutilation, but may have been brought about 

 by disuse; though no one has explained why the two sexes 

 should differ in this respect. Many insects use the legs to 

 clean the antennae, head, mouth parts, wings or legs ; the honey 

 bee (with other bees, also ants, Carabidse, etc.) has a special 

 antenna-cleaner on the front legs (Fig. 263, D), which is 

 described, with other interesting modifications of the legs, on 

 page 271. 



Indeed, the legs serve many such minor purposes in addi- 

 tion to locomotion. They are generally used to hold the 

 female during coition, and in several genera of Dytiscidse 

 (Dytiscus, Cybister) the male (Fig. 62, /) has tarsal disks and 

 cupules, chiefly on the front tarsi, for this purpose. Among 



