INSECTS AND MANKIND 425 



immigrant to Britain than Blatta orientalis, is said to super- 

 sede its larger, darker relation in many habitations. Certainly 

 it is often present in swarms in the kitchens of old town 

 dwellings, and in or under the cages of monkey-houses in 

 menageries. The large brown American Cockroach (Peri- 

 planeta americana), whose original home was in warm 

 transatlantic countries, is now often abundant on ships 

 and in the sheds of docks and wharves ; it may also be 

 found in greenhouses, at times in company with its close 

 ally P. aiistralasiae, introduced from far Eastern tropics 

 with imported plants. 



Man's insect messmates comprise quite a number of 

 small beetles that live in grain, flour, and other foodstuffs, 

 and often increase in numbers so as to become serious pests. 

 The beetle Tenebrio molitor, with its elongate brown larva 

 the " mealworm," is found throughout the world in stores 

 of cereals ; the grubs pay some small compensation for their 

 depredations by themselves serving on occasion as provender 

 for pet birds. Two smaller " Flour Beetles," Triholitm 

 ferrugineiin and T. confusum, belong to the same family as 

 Tenebrio and live in much the same way. Stores of grain 

 as well as ship-borne cargoes are often infested with two 

 small weevils, Calandra granaria and C. oryzae. During 

 the Great War of 19 14-18 the damage done by these and 

 other food-devouring insects became so serious that in 

 view of the shortage of supplies, a special government 

 commission was appointed to inquire into the ravages of 

 . those insects that must be regarded as pests in ware- 

 houses and on board ship. The common little beetle 

 Anohium paniceian which feeds in great variety of stored 

 foodstuffs is often known as the " biscuit weevil " because 

 of its destructive action on ship's biscuits, though it is 

 systematically far removed from the true weevils (Cur- 

 culionidae), being a member of the Clavicorn family 

 Ptinidae. Various beetles of this family have become 

 established as messmates in human dwellings and store- 

 houses feeding not only on edible grains, meal, and dried 

 fruits, but on drugs (including poisons such as opium, 



