CHAP. Will.] PESTS OF STORED PRODUCTS. l6l 



ripening grain, but it is an important pest of stored grain, especially 

 of rice, but also of maize, whr.it, cholam, etc., and at a moderate 

 estimate may be said to destroj 5 per 1 ent. of all stored grain 

 which is kept for more than a couple of months after harvest. The 

 whole lite-history is passed in a single grain in which the egg 

 is I. ml, hui the adult beetles live tor a long time and wander 

 aboul freely, biting into many grains, so that they probably do 

 mure damage as adults than when immature. It has been found 

 by experiment that ,1 certain minimum (about 8 per cent.) of 

 moisture in their surroundings is necessary to the successful exist- 

 ence and breeding of these weevils, so that, if grain can be well 

 dried in the sun to reduce 1 1> moisture-content as much as possible 

 and then stored in insect-proof receptacles in a dry place, it will be 

 as secure from attack as is possible under practical conditions. In 

 districts where paddy is stored in jars there should be little 

 difficulty in having the grain sun-dried before storage and then 

 fastening up the jars so as to exclude weevils ; for jars not in use 

 an earthenware cap, luted on with claw might be used, and those 

 in daily use could be covered simply with a fine cloth tied around 

 the neck of the jar. Can' should of course be taken that the jars 

 are thoroughly ( leaned out and free from weevil or old infected grain 

 before filling them afresh and also that all fastenings are really 

 sufficiently tight to be weevil-proof. If the grain is kept in baskets 

 these should at least be plastered over with mud or cowdung to 

 make them tight if possible. 



Triboliiim castaneum (ferrugineum) is a small elongate red-brown 



tie which attacks stored grains and oilseeds and more especially 

 dried provisions, such as biscuit and Horn. It also feeds on dried 

 animal matter and seems to have a special predilection for dried 

 specimens of insects if these an- left exposed in ill-fitting boxes. 

 Not only does this beetle do damage by actual consumption of 

 provisions such as flour, but its presence communicates a peculiarly 

 repulsive taste to the substances on which it feeds, so that whole 

 5 oi flout and biscuits often have to be condemned as unfit foi 

 human consumption on this ground alone. 



Silvanus stirinamensis, so called because it was first described 

 from Surinam, is a small elongate brown beetle with the sidi 

 the thorax produced into sharp saw-like teeth. It is a common 

 insect in stored products generally but a minor pest in comparison 

 with the two preceding species. 



The Bruchidae, 01 Pul B , are short thick-bodied species 



of the characteristic shap. seen in figure 155. Hiey attack especially 

 pulses such as the various grams, lablab, beans and peas, the larva 

 burrowing inside the seed and destroying it and leavii 



