338 
COLEOPTERA. 
in wliicli the upper surface is somewhat granulose, and Opatrum. 
depressum, Fabr., which is figured here. These species occur sometimes 
in incredible numbers ; we have seen a field of six-foot-high indigo so 
infested that every stem was black ; the beetles always shun light and 
in the dense indigo crop they live in shade and feed on the abundant 
dry leaves that fall. When the crop is cut they are brought in with 
it to the vats and sometimes cover the surrounding masonry, etc. A 
number of beetles were confined in the insectary and fed on these 
leaves ; larvae were eventually found which were reared without diffi¬ 
culty but which lived wholly on the surface of the soil under the cover¬ 
ing of leaves. On first seeing the multitudes of these beetles that exist, 
one is tempted to wonder where their larvae could have been ; we 
realise it after having reared them and it is possible then to dimly see 
how vast may be the fauna hidden away like this on the soil and how 
important their work of disposing of plant refuse is. Opatrum apparently 
like most of its family, is wholly a feeder on dead or decaying vegetable 
tissue and the beetles have been found to even eat planks laid on the soil. 
The genus Toxicum is marked by the erect horns of the males ; 
these beetles are found under bark ; the function of the horns is 
unknown. The two species 
of Tribolium occur widely 
spread, T. ferrugineum , Fabr., 
T. confusus , Duv. Both are 
pests of stored produce and 
occur frequently in dried in¬ 
sect collections. The latter 
is stated to be abundant in 
America, but we have been 
unable to recognise it in our 
long series. We reproduce 
the figures illustrating the 
differences in the two species 
in Chittenden’s paper (U. S. 
Dept, of Agri. Ento. Bull., 
N. S. 4). It is, however, re¬ 
corded from rice in Rangoon 
Fig. 215.— Tribolium confusum, A. head 
OF T. CONFUSUS, B. FERRUGINEUM. 
[After Chittenden.) 
