Beetles 
2 93 
get on to the body of the female of one species of bee; but it has no dis¬ 
crimination whatever of the kind of object it requires, and, as a matter of 
fact, passes with surprising rapidity on to any hairy object that touches it; 
hence an enormous majority of the young are wasted by getting on to all 
sorts of other insects; these larvae have been found in numbers on hairy 
Coleoptera, as well as on flies and bees of wrong kinds; the writer has ascer¬ 
tained by experiment that a camel’s-hair brush is as eagerly seized, and 
passed on to, by the young Meloe as a living insect is.” 
The commonest Eastern species of blister-beetles belong to the genus 
Epicauta. They feed when adult on the leaves of potato—being therefore 
often called potato-beetles—and on the pollen of goldenrod. E. pennsyl- 
vanica is uniformly black; E. cinerea is grayish black or even ashy, always 
with the margins of the elytra gray; E. vittata (Fig. 401) is yellowish or reddish 
above, with head and prothorax marked with black and with two black stripes 
on each elytron. In Meloe the wings are lacking and the elytra short and 
diverging; M. angusticollis , the buttercup oil-beetle, i to J inch long, 
of violaceous color, is the commonest eastern species. In the west the 
commonest blister-beetles are metallic green and blue and belong to the 
genus Cantharis. 
Another small family of rarely seen heteromerous beetles, which, how¬ 
ever, possess an extremely interesting and wonderfully specialized life-history 
and show a marked degenerate structure due to their parasitic habits, is 
the Stylopidae, or wasp parasites. Indeed these 
curiously modified beetles differ so much from 
all the other Coleoptera that some entomolo¬ 
gists look on them as composing a distinct order 
which these naturalists call Strepsiptera. The 
males are minute with large fan-shaped wings 
and reduced, short, club-like elytra. The 
females are wingless and never develop beyond 
a larval or grub-like condition. They live in 
the body of a wasp or bee (Fig. 403)—certain 
foreign species parasitize ants, cockroaches, and 
other insects—while the free-flying males live from only fifteen or twenty minutes 
to a day or two: three days is the longest observed lifetime of active adult 
existence! The youngest larva of the Stylopids—the egg-laying has not 
been observed—is a minute, active, six-legged creature, not unlike the Meloid 
triungulin, which attaches itself to the larva of a bee or wasp and burrows 
into its body. There it lives parasitically, meanwhile undergoing hypermeta¬ 
morphosis in that after its first moult it becomes a footless maggot or grub. 
In this state it continues until, if a male, it pupates in the host’s body and 
issues for its brief active adult life. If a female, there is no pupation, but 
Fig. 403.—A wasp, Polistes sp., 
parasitized by (a?) Xenos sp. 
(After Jordan and Kellogg; 
slightly enlarged.) 
