158 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
a few steps ahead of the intruder, only to ahght suddenly in an open 
spot and turn to face him in an aggressive posture. These so-called 
tiger beetles are well named, for like their cousins, the ground beetles, 
they live by preying on other insect life. Their method of suddenly 
pouncing on their prey still further carries out the metaphor. 
In striking contrast to the active habits of these adult beetles, their 
early life as larvae is spent in cylindrical burrows in the hard-packed 
ground. In these holes the larvae patiently wait with their heavily 
chitinized heads and long, upward-turned and toothed mandibles pro- 
jecting to grasp the unlucky insect that may wander by. In order to 
prop themselves in the top of these burrows and possibly to prevent 
larger prey which they may grasp from pulling their bodies out of 
the holes, the fifth abdominal seoment is provided with a hump and two 
or three pairs of recurved hooks. 
Ramity CUPESIDAE 
A single species of the family Cupesidae, Cupes concolor Westw., 
is mentioned here, not so much because of its economic importance, as 
it feeds only in moist rotting wood, but because of its peculiar larva. 
This is an elongate, fleshy, soft-skinned larva, 20 to 25 mm. in length 
when full grown, adapted to wood boring. The head is somewhat em- 
bedded in the prothorax, and the ninth abdominal segment ends in a 
short truncate spine. The legs are fleshy, five-jomted, and provided 
with a movable claw, a character common also to the families Rhy- 
sodidae and Micromalthidae, and a feature characteristic of the sub- 
order Adephaga, in which this form has been placed. These charac- 
ters will distinguish the larva from any other Coleoptera, but in 
addition, the mandible is provided with a molar structure which grinds 
against a strong hypopharyngeal chitinization, 
The adult is slender, somewhat depressed, 7 to 11 mm. in length, 
grayish brown and covered with small ale and has brownish 
blotches forming three indistinct bands on the elytra. The head is 
tuberculate and constricted into a neck; the antennae are slender and 
about as long as the body. | 
The larvae feed in decaying, moist wood and are often found in the 
basement timbers of old houses. Usually the wood is so permeated 
by decay that the insects cannot be considered as injurious. They 
have been found in pine, chestnut, and oak, and probably attack many 
other woods. 
Famity MICROMALTHIDAE 
Micromalthus debilis Lec., a minute, black shining beetle, 2 to 3 mm, 
in length, related to Cupes and Clinédium, is mentioned because of tts 
remarkable larva and complicated biology. The larva is thin-skinned 
and soft, with five-jointed legs, each leg provided with two claws, and 
the ninth abdominal seoment carries a pair of recurved terminal 
spines, one ventral and one dorsal. The ligula and hypopharynx are 
chitinized, and the mandible has a well-developed molar structure. 
Several distinct larval forms have been described by Barber (27) 
and by Pringle (358), such as caraboid, cerambycoid, and curculioid, 
which appear during the complex metamorphosis of this species. The 
most unusual characteristic, however, is that certain stages of the 
larva give birth to living young of the caraboid type of larvae. 
