1350 PAMIIA' LXIV. MELOID/K. 



the medinii iiiiinvssiuii visililc at liase only. lOlytra paralli'l. C'oarsclj' and 

 rather closely i)unetate. Male anteniife with last joint as long as the five 

 preceding, their branches as in bicoJor. Length 11-18 mm. 



Laporte County ; rare. May 25. Taken from beneath bark of 

 pine. 



Family LXIV. INIELOID.F.. 

 The Oil axd Buster Beetles. 



^Mediiiiu or large-sized ])eetles of variable color, having the tho- 

 rax narrower than either head or elytra ; the bodies soft in texture, 

 often loose- jointed and sprawly in appearance and usually slender 

 and subcylindrical in form ; antennie of moderate length and in the 

 male sometimes curiously knotted or otherwise modified; head 

 l)road, vertical and abruptly narrowed into a neck; elytra and sides 

 of abdomen with little or no co-adaaptation ; tarsal claws cleft or 

 toothed, each claAv usually bearing a long appendage closely applied 

 beneath it. 



The name IMeloida; is of uncertain derivation. The larger, more 

 bulky species, belonging to the genus Meloe, when alarmed exude 

 from the joints of the legs a yellowish oily liquid, whence the name 

 "oil beetles," often applied to them. To our more common forms 

 the name "'blister beetles" is given, on account of their possessing 

 a peculiar principle called cantharidine which, w^hen extracted and 

 applied to the human skin, possesses the power of raising blisters. 



In the adult stage the blister beetles are often injurious, since 

 they feed on cultivated plants such as beets, potatoes and tomatoes, 

 and a niuuber of them are called "old-fashioned potato beetl&s, " a 

 term in use only since the Colorado potato beetle invaded the East. 

 In the larval stage, however, many of them are very beneficial, as 

 they feed upon the egg-pods of our eomnK)n grasshoppers, thus 

 greatly lessening the numbers of these insects. The larva? of the 

 ])lister beetles are also peculiar in that they undergo several more 

 changes than do ordinary beetles before reaching the adult stage, a 

 pseudo-pupal or inactive stage following the usual three or four 

 moults of the larval form, this being succeeded by an active stage, 

 which in turn is followed by the usual pupal stage preceding the 

 final moult. The larvje of the "oil beetles" live in nests of bumble- 

 and other bees, feeding upon the honey stored for the young bee, 

 and hence are also injurious in this stage. 



In addition to the more important characters mentioned, the 



