lOG 



THE AGRICULTURAL NEWS. 



April 4, 1908. 



INSECT NOTES. 



Practical Remedies for Insect Pests. 



The concluding portion of Mr. Ma.xwell-Lefroy's 

 article (reprinted from the A<iri.cidturiil Jojirnal of 

 India), dealing with methods of destruction of common 

 insect pests, is given below : — 



A familial- pest tf) cultivatms in .^om^.• [larts of India, 

 and also in other parts of the world, is the eoninion white 

 ant. Investigation ill) t'"' tl^^' pre.sent shows that the destruc- 

 tive 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 mound.s above the surface of 

 the .soil. Where the termites nest deejdy as in the deeji 

 alluvial soils of the Gangetic and Indus plain.s, practical 

 means of checking them are difficult to find ; Ijut where 

 they nest at the .surface, a great deal can be done to check 

 them by the .systematic destruction of I he nests : the .simplest 

 method is to dig into the nest and pour in abundant boiling 

 water ; the sign of success is when the very large white 

 fiueens 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 Imlia, there is no reason why any termite nest should 

 be billowed to remain, and a little systematic cttbrt by each 

 village would keep the land pi'actically free from this 

 destructive insect. 



Another common pest is the weevil whose grub tunnels 

 in sweet [xrtato.s, rendering them wholly nidit for food. We 

 have seen fields, where a crop has been dug, covered with 

 potatos which were thoroughly infested and left to breed 

 weevils, thus providing m plenlifnl supply of insects to infest 

 other fields or the next ciop. This might reailily be avoided 

 if these potatos were gathei'ed and buried in a pit under 

 a. fi>ot of luird trodden soil. It is only puic coinnion-sense to 

 take such a precaution anil so prevent tlic ninll iplication of 

 the insect to attack the ne.vt crop. 



For some pest the bag and frame so extensively used in 

 the destruction of the lioppers of the liondiay locust is 

 a jiractical niitliod. 'i'he surface grasshoppers do a very 

 large amount of (himnge yearly among the young crops. 

 They 'lie llattcnrd illicit-, white below, with the upper 

 .surface rougliencd and eiirthv in icilour ; thcv abound in 

 the fields and hop out js one walks along. If a wide 

 bag on a frame is run tlirongli the field fairly rapidly, 

 the grasshopper, ms it jumps up, is caught liy the bag 

 and swept up. At the end of each run the bag is twisted up 

 and the insects are shaken into a corner and destroyed. 

 In this way a large area can be rapidly and thoroughly cleared 

 either before the cro}) is up or while the plants are still young. 



The bag in its vai'ious forms is useful in many cases where 

 its application is once understood, and it provides the most 

 practical remedy against a fairly universal i)est of rice, the 

 rice bug. 'I'iiis is a slender green insect, which flies readily 

 when full-grown ; it emits the u.sual aromatii' odour of its 

 class, and an infested field may often be known by that alone. 

 As the rice conies into car, the bugs assemble there and .suck 



out the milky juice in the develo])ing sfrain. The grain then 

 whitens and the ear has nothing in it when it comes to harvest. 

 A light bag, S feet wide, run rapidly thrfiugh the field, brush- 

 ing the tops of the rice, sweeps up these Ijugs, and though .some 

 escape, the Ijulk are captured. A bag must be used, as the 

 insects escape from a [ilain cloth, unless it is smeared 

 with sticky matter ; the bag is considerafily nujre effective if 

 first soaked in kerosene, or in an emulsion made by shaking up 

 kerosene with sour milk. This method like the others men- 

 tioned above is in aijplieation on the Pu.sa farm, where ordinary 

 coolie labour is employed ; as socni as the bug is found the 

 bag is used and there is no difficulty in checking this jiest. 



liice is constantly attacked by another class of pest, 

 which \ields to simjile treatment if that treatment is carried 

 out o\ei- any area larger than a few acres. This pe.st is the 

 stem borei-, a caterpillar which eats ujj the centre of the grow- 

 ing shoot of the rice and kills it. The result is that each 

 .shoot withers, and as a single caterpillar in many cases attacks 

 several shoots, the damage to the ripening crop is considerable. 

 This form of damage is reported from practically every rice- 

 growing tract in India ; several in.sects aie concerned which 

 are all (|uick breeders, and of which tun or three broods 

 complete their life-history in one crop. For all these there is 

 but (pue practical cure : that is, to pick them all (mt from the 

 beginning. If the cultivator would learn that withered rice 

 .shoots contain a caterpillar which, if left alone, breeds and 

 niulti|)lies (|uite naturally, he might .systematically pick out 

 and burn all withered shoot.s. These are sufficiently ea.sy to 

 see, and it does not reipiire much time or labour to go over 

 some acres of jiaddy. Were this known to the cultivator, and 

 were he to do it, we believe that no cases of destruction by 

 these |)ests would ever be seen. In some cases, it is possilile 

 also to utilize another method, depending upon tlu' fact that, 

 like the moth liorer of cane, the stei'i borer of rice sjieuds the 

 cold weather or liol weatliei' when the crop is not growing, 

 in the stubble. Where this stubble can be taken out and des- 

 troyed, it destroys tlio.se in.sects which live over until the 

 next crop and then emerge to breed. How fai- the destruc- 

 tion of rice stubble is possible depends upon locul conditions, 

 but it is always a valuable .safeguard. 



It is |)erhaps needless to multiply instances of simple 

 methods of destruction. For very many pest.s, the renieily is 

 there to hand, namely, to destroy the insects when they first 

 appear, and so to save tlu' later destruction <'aused by their 

 natural increa.se. We have cited cases eniaigh to show that, 

 in very many instances, there are simple methods by which 

 the cultivator could materially les.sen the losses caused to his 

 irop by insects. It is |)eihaiis needless to say that there are 

 othei- ca.ses where eiiually simple remedies couhl be devised 

 //// //(( riiltivntar, if he knew how his pe.sts lived and multi- 

 plied. In most ca.ses, the .scientific study of an injurious insect 

 shows what its weak points aie. but to take advantage of 

 them re(|iiires also a very thorough knowledge of local agri- 

 culture, which no one per.son can have for more than a limited 

 area. The treatment of .such pests must be a matter for the 

 future, but there seems to be no reason why efforts should 

 not now be made to bring home to the cultivator the facts 

 regarding such simple pests as it is possible for him to cure, 

 and thereby to open his mind to the realization of the fact 

 that the knowledge of the pest's life-history is the first 

 essential, and that, given this, it is often within his scope to 

 devise .some means of circumventing the enemy. The cases 

 enumeialed above are cited as being those in which there 

 exists a simple practical remedy for a particular pest. If the 

 cultivator can be induced to adopt one of these and so to 

 lessen the damage to his crop in any one case, a great step 

 forward will have been made. 



