260 
COLEOPTERA. 
mud near rivers ; apparently they require wet material which admits of 
the formation of a burrow, but their choice of locality may be determined 
by their prey^; the burrow extends 
vertically from the surface and the 
larva can move up and down by 
means of the legs and a dorsal hump 
or projection; the head is flat, used 
to carry up the soil when excavating, 
and the very long jaws are turned 
backwards and upwards, so that 
when the flat head is blocking the 
upper end of the tunnel, the jaws 
have free play above and are in a 
position to seize any unwary insect 
that alights or walks within reach. The length of the life-history has 
not been ascertained, but as each species appears to emerge in the imago 
form for a definite period in the year, it is probable that the life-history 
occupies one year or multiples of one year ; the imago lives for several 
weeks. The student should read the life-history of Cicindela campestris, 
an English insect, which occupies three years (Proc. Ent. Soc., London, 
1903, p. XV 7 ). R. Shelford figures the curious larva of Collyris emargi- 
natus, Deg. from Java, which lives in burrows in coffee stems, feeding on 
the insects that go past. The larva has on the fifth abdominal segment 
six hooks, curved forwards, on a protuberance. A similar larva was 
found in China (Trans. Ent. Soc., London, 1907, p. 83). 
The majority of these beetles appear in the rainy months, some 
at the beginning, some later. Our common species are diurnal in habit, 
though some are known to be nocturnal. They are among the most 
active of insects, flying for short distances with great rapidity and also 
running quickly. So far as known all are predaceous on other insects, 
though their exact economic value is difficult to ascertain. Maindron 
records that Derocrania longesulcata, Mon., feeds on Silis (Drilinse), 
and such records of food are noticeable for their rarity. The majority 
are found in damp places, in rice fields or thick vegetation, on river 
banks, on the seashore ; some are found only on trees in forest localities. 
Some are known to emit scents, not of an unpleasant character, but 
Fig. 149 .—Cicindela larva, x 2 
