TEOCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 35T 



field crops such as sugarcane, rice, wheat, barley, maize, etc. They 

 gnaw the roots of plants but more often the base of the stem, causing 

 entire young plants and shoots to wither. Usually they avoid wet and 

 muddy places and are common in all moist soils. Thus, rice plants- 

 standing in water or growing in muddy places are immune but are liable 

 to attack when the water dries up. Most of the other important crops 

 such as sugarcane, wheat, barley, etc., cannot be grown in water and the 

 moist soils in which they can be grown are the most favourable situations 

 for termites' activities. Only in the case of sugarcane have attempts 

 been made to check their ravages. The setts are liable to be attacked 

 as soon as they are placed in the ground and in the worst cases all the 

 setts may be eaten. Trials in treating the setts with chemicals, etc., 

 which can act as repellents, formed a subject-matter of discussion at the 

 Second Entomological Meeting and the information regarding them will 

 be found at pages 137 — 139 of the published Proceedings of that Meeting. 

 It is a common behef that sugarcane setts are attacked only through the 

 cut ends and recommendations have been made to protect the ends by 

 dipping them in melted resin. Our experience has been that setts 

 may be attacked at any point on their surface as well as at the ends and 

 that it is the young shoots which require to be protected more than the 

 setts. Our observations at Pusa as well as outside and the experiments 

 which we have carried out to protect setts against termites go to show 

 that the hability of cane to damage by termites depends largely on the 

 nature of the soil in which it is grown. Generally speaking, the crop 

 suffers much less or not at all when grown in clayey soils than in sandy 

 soils. In soils which are liable to be infested by termites no single treat- 

 ment of the setts can render them immune nor can any treatment of the^ 

 setts save the shoots ; whilst in other soils little or no damage is done by 

 termites either to setts or to shoots even when no treatment is adopted. 

 Later on, when we come to discuss damage to sugarcane by the borers>. 

 we shall see that sugarcane grown in Ckaunia field at Pusa in 1917 suffered 

 very httle from termites without treatment, and in the Brickfield both 

 treated and untreated plots suffered equally heavily. In order to find 

 out what it is in the soils which makes this difference the first step we 

 have taken is to subnut the soils for analysis to the Imperial Agricultural 

 Chemist to whom we have to acknowledge our thanks for undertaking 

 this work. We quote below the results of his analyses of the surface 

 nine inches of soils of the places where no or httle damage was done as 

 well as of the places where damage was severe. There are small differ- 

 ences in the constituents of the soils but without further experiments 

 which we have in hand we cannot hazard any opinion. 



