214 A. D. PEACOCK — ENTOMOLOGICAL PESTS 



pests have been noticed. The beetles, Lagria villosa, F., and L. viridipennis, F., 

 and the locust, Zonocerus variegatus, L., are general leaf -eaters which also 

 frequently damage maize. 



Beetles that attack stored grain. 



It is unnecessary to enlarge upon the habits and life-histories of these 

 universal pests, foremost among which are, Calandra oryzae, L., Tribolium 

 castaneum, L., Laemophloeus pusilhcs, Schon., and Silvanus snrinamensis, L. 

 They have been already well worked out, Calandra oryzae by the Entomological 

 Department of India and the others by the Agricultural Department of the 

 United States. 



The main problem was the destruction of the pests. This is not very difficult 

 if modern methods of storing and fumigating are employed, but it is a different 

 matter where no facilities exist. A certain amount of work, though little, was 

 done. 



The natives often store maize in their huts on shelves above the cooking place, 

 so that heat and smoke may circulate among the corn and, presumably, destroy 

 any pests present. Experiments were therefore commenced to ascertain what 

 practical value this method possessed for storing seed on a large scale for food 

 and market. Cobs with the sheath leaves, stripped cobs, and seeds, to the 

 amount of two tons, were placed in sacks, palm oil pots and securely lidded or 

 sealed kerosene tins. They were stored in a rain-proof native hut about 24 ft. 

 by 12 ft. and were arranged on shelves round the hut about 3 ft. and 5 ft. from 

 the ground. Two hot fires were made or replenished in kerosene tins every day 

 at 6 a.m., 8 a.m., 12 noon, 2 p.m., and 5 p.m. They were moved at intervals so 

 that different portions of the maize received a due proportion of heat and smoke. 

 One man was kept practically all day at the work. 



During the last fortnight of the Entomologist's tour when the experiment was 

 under his supervision, the temperature of the hut could not be raised to more than 

 85° F. Of course the temperature of the maize directly above the fires was 

 hotter ; indeed, in some cases it was scorched. 



As much heat as could be obtained with safety was obtained, but without 

 checking the ravages of the pests. Even the increased heat induced in the 

 tightly packed seeds had no effect. The results, after continuing the work for a 

 long time, might have improved. But even if they did, sufficient was done to 

 show that the method was too cumbersome and risky for any problematic value 

 it may possess. The same amount of labour put into fumigation methods would 

 attain, far more efficiently, the end desired. 



The fumigatorium which is being built at Ibadan is a most necessary building. 

 But fumigation carried on under European control and the popularising of 

 fumigating methods among the natives are different matters. Carried out 

 willingly and with understanding, fumigation by the native ought to be a fairly 

 simple matter. All the apparatus required is substantial air-tight receptacles, 

 sufficient in size and number for the needs of the crop, and a quantity of carbon 

 bisulphide. It is suggested that, as the making of air-tight wooden boxes in the 

 Colony has been found very expensive, it may be cheaper to have the parts 



