496 MAIZE 



CHAP. 467. The Angoumois Grain-moth (Gelechia cerealella). — 



' • The eggs of the moth are laid on the grain and in due course 

 the larva, in the form of a minute caterpillar or "worm," as in 

 the case of the grub of the weevil, bores its way into the soft 

 part of the grain, feeds and grows, pupates and finally emerges 

 as a full-grown moth, ready to mate and lay a fresh lot of eggs. 

 The holes in the grain formed by the larva of this insect are 

 shown on Fig. 191. 



468. Remedies for Insect Pests. — The storage of grain in 

 weevil-proof tanks and silos greatly reduces the loss from this 

 source, but it is not entirely effective because weevils and grain- 

 moths (in the egg or larval stage, or even as adults) may be 

 brought into the tanks with the grain, and thus start fresh 

 infection. An application of carbon-bisulphide in the propor- 

 tion of 1 lb. to 1 ton of grain or in empty tanks or stores 

 I lb. for every 1,000 cubic feet, is said by entomologists 

 to be the simplest and best remedy. This substance is highly 

 explosive, and the greatest care must be exercised that no 

 light be allowed in or near the place where the carbon-bisulphide 

 is in use. 



The late Mr. C. B. Simpson, Entomologist of the Trans- 

 vaal Department of Agriculture, replied as follows to a corre- 

 spondent, in the Transvaal Agricultural Journal ; — 



" You are indeed unfortunate on account of the fact that your 

 mealies became infested in the field. The weevil usually hides 

 in cracks and crevices, or in grain which is strewn about and 

 attacks the new grain as soon as it is stored. A thorough 

 cleaning of the building in which mealies are to be stored is, 

 therefore, one of the best preventive measures. Many farmers 

 in Natal and Cape Colony have found that large tanks, made 

 of corrugated iron, are most admirable for storing mealies. 

 These tanks, which hold from fourteen to fifteen bags of mealies, 

 are filled almost to the top with the grain and a lighted candle 

 is placed in the tank and is allowed to burn until the air is 

 exhausted, after which the tank is securely closed. Some 

 farmers go so far as to state that this burning candle kills all 

 the weevils already in the grain and prevents others from 

 entering ; I do not, however, place any confidence in the 

 candle as a destroyer of insects, but on account of the fact that 

 the tank is tight, no insects can enter. Bags of mealies may 

 be stored in tight iron buildings or large tanks. The ideal 



