2 7 O COLEOPTERA 



and applied to the human skin, possesses the power of raising 

 blisters. The life-history is highly remarkable, the most complex 

 forms of liyper-metamorphosis being exhibited. The species now 

 known amount to about 1500; there can be no difficulty in 

 recognising a member of the family by the above characters, 

 except tliat in a very few cases each claw bears a projecting 

 tooth, instead of an elongate appendage parallel with itself. The 

 penultimate tarsal joint is scarcely ever broader than the pre- 

 ceding : the colour and style of markings are extremely varied. 

 There are two very distinct sub - families, Cantharides and 

 Meloides ; the former are winged Insects, and are frecpiently 

 found on flowers or foliage. The Meloides are wingless, and 

 consequently terrestrial ; they have a very short metasternum, 

 so that the middle coxae touch the hind ; and they also have 

 very peculiar wing-cases, one of the two overlapping the other 

 at the base ; in a few Meloids the wing - cases are merely 

 rudiments. 



The post-embryonic development of these Insects is amongst 

 the most remarkable of modern entomological discoveries. The 

 first steps were made by Newport in 1851,' and the subject 

 has since been greatly advanced by Fabre, Eiley, and others. 

 As an example of these peculiar histories, we may cite Ei ley's 

 account- of Ejncanta vittata (Fig. 140), a blister-beetle living 

 at the expense of Xorth American locusts of the genus Calop- 

 tcMis. The locust lays its eggs underground, in masses sur- 

 rounded by an irregular capsule, and the Epicauta deposits its 

 eggs in spots frequented by the locust, but nut in special 

 proximity to the eggs thereof. In a few days the eggs of 

 the blister-beetle hatch, giving rise to little larvae of the kind 

 called triungulin (Fig. 140, A), because each leg is terminated by 

 three tarsal spines or claws. In warm, sunny weather these 

 triungulins become very active ; they run about on the surface 

 of the ground exploring all its cracks, penetrating various sjiots 

 and burrowing, till an egg-pod of the locust is met with ; into 

 this the triungulin at once eats its way, and commences to devour 

 an egg. Should two or more triungulins enter the same egg-pod, 

 battles occur till only one is left. After a few days passed in 



^ ■' Oil the Natural History, Anatomy, and Develoimient of the Oil-Beetk', 

 Meloc," Tr. Linn. Hoc. .\.x. 1851, p. 297 ; and xxi. 1853, p. 167. 

 - llci^. U.S. cnt. Commission, i. 1878, p. 297. 



