April 1908.] 



333 



Plant Sanitation. 



have the insect in them. In many juar- 

 growing districts, especially in the 

 Central Provinces and Bombay Pre- 

 sidency, this hibernates in juar and the 

 caterpillar is constantly found in the 

 stumps left in the ground after the crop 

 is cut. The removal of these stumps is a 

 very valuable remedy, since it removes 

 the pest when it has no other refuge and 

 destroys the insects that would other- 

 wise do much harm later in the season. 

 This is a practical measure well worth 

 impressing on cultivators ; they know 

 the insect, they can be shown it in the 

 juar stump, and though they do not 

 understand its transformation, yet they 

 are open to the commonsense suggestion 

 that these insects will increase later on 

 and attack their crop. Most of these 

 remedies are pure commonsense, and if 

 we could find such weak points in the 

 life of every pest, we would be able to 

 deal more effectively with the problem. 

 Apart from their value as remedies, they 

 are valuable also as demonstrations ; it a 

 start can be made by demonstrating 

 such simple remedies, and the ryot can 

 be induced to take them up at times 

 when the losses from the pest are fresh 

 in his mind, the foundation for further 

 work in checking preventible loss will 

 be laid. It is astounding how univer- 

 sally the simplest remedies are un- 

 thought of by the mltivator, apparently 

 because the question of checking pests 

 never suggests itself until the overwhelm- 

 ing numbers of a caterpillar or grass- 

 hopper make a practical remedy an im- 

 possibility. In very many cases, if the 

 possibility of checking the insect was 

 known to the ryot, he would, from his 

 own intimate knowledge of his crops, be 

 able to prevent or check much of the 

 loss that constantly occurs. 



A case in point is the brinjal crop, a 

 paying vegetable crop grown for long 

 periods on land that can be irrigated, to 

 supply a local market, This plant is 

 destroyed by a caterpillar that tunnels 

 in the stem, and that sooner or later so 

 interferes with the upward flow of sap 

 that the plant suddenly withers ; the 

 cultivator then pulls up that plant and, 

 if not too late, puts in a young one from 

 which he may hope to get a small yield. 

 The withered plant he lays somewhere 

 near by, with the borer in ; this presently 

 transforms and emerges to lay eggs in 

 large numbers on other plants. Had the 

 cultivator burnt his plants from the very 

 first, plucking them out regularly as they 

 withered, he would have prevented the 

 very large loss in the later growth of the 

 crop, a loss that often means a great 

 reduction in the yield of the field. 



Til is a crop from which two pests are 

 very commonly reported ; one is a large 



green caterpillar, with bright oblique 

 stripes on its sides, and a curved horn at 

 the hind end. It grows to a length of 

 three inches and is very conspicuous. 

 The other is a small caterpillar, creamy 

 green, with little black specks, which 

 rolls the leaf and bores in the capsules. 

 Both yield to the same treatment, des- 

 truction by hand token they first com- 

 mence ; the smaller caterpillar especially 

 is checked by this treatment as its life 

 is short, it multiplies very rapidly and 

 it often is very injurious to the seed 

 capsules as the crop ripens. In this case 

 again, it is cheaper and equally effective 

 to remove by hand as to spray with an 

 arsenical poison. 



A familiar pest to cultivators in some 

 parts of India is the common white ant ; 

 investigation up to the present shows 

 that the destructive white ant of the plains 

 is one species only ; in some parts of the 

 country it nests below ground, in others 

 at the surface or it builds up mounds 

 above the surface of the soil. Where 

 the termites nest deeply as in the deep 

 alluvial soils of the Gangetic and Indus 

 plains, practical means of checking ter- 

 mites are difficult to find ; but where 

 they nest at the surface, a great deal 

 can be done to check them by the syste- 

 matic destruction of the nests ; the 

 simplest method is to dig into the nest 

 and pouc in abundant boiling water ; 

 the sign of success is when the very large 

 white queens are obtained as they are 

 found only in the nest itself, and if these 

 are destroyed with as many of the 

 smaller termites as possible, the termites 

 cannot increase until they build up a 

 new nest and rear a fresh queen. In 

 some parts of India, there is little reason 

 why any termite nest should be allowed 

 to remain, and a little systematic effort 

 by each village would keep the land 

 practically free of this destructive insect. 



Another common pest is the weevil 

 whose grab tunnels in sweet potatoes, ren- 

 dering them wholly unfit for food. We 

 have seen fields, where a crop had been 

 dug, covered with potatoes which were 

 thoroughly infested and left to breed 

 weevils, thus providing a plentiful supply 

 of insects to infest other fields or the 

 next crop. This might readily be 

 avoided if these potatoes were gathered 

 and buried in a pit under a foot of hard 

 trodden soil. It is only pure common- 

 sense to take such a precaution and so 

 prevent the multiplication of the insect 

 to attack next crop, 



For some pests the bag and frame so 

 extensively used in the destruction of 

 the hoppers of the Bombay Locust is a 

 practical method. The surface grass- 

 hoppers do a very large amount of 



