88 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



because it appears to be nobody else's business to do any- 

 thing in this line. They cut the rice-plants, especially the 

 young plants, and are reported to damage rice in this way in 

 Burma, Madras, some parts of the Bombay Presidency and 

 also in some parts of Bihar. They are known to occur in 

 rice fields in Western Bengal but not as doing any damage 

 there. About six miles from Pusa there is a large rice- 

 growing tract known as Barail where crabs were reported 

 to be doing great damage, and this locality was visited in 

 October, at the end of the Rains, and again in April, in the 

 dry weather. The crabs collected from the rice-fields here 

 were identified by Mr. S. W. Kemp, as belonging to three 

 distinct species, viz., (1) Paratelphusa (P.) spinigera, Wood- 

 Mason, (2) Potamon (Amnthopotamon) martensi, Wood- 

 Mason, (3) Potamon (A) sp. nov. allied to wood-masohi, 

 Aloock. Apparently all these three species are not con- 

 cerned in the damage to rice, but it requires further observa- 

 tions to determine which species are incriminated. From 

 observations made hitherto it appears that these crabs take 

 three or four years to become fullgrown and "capable of 

 reproduction. In the hot weather they go deep down into 

 the soil, coming out and resuming activity in the Pains. 

 From a dry field at Munni, in the Muzaffarpur District, in 

 April five crabs, young as well as adults, were collected at a 

 depth of between 11 and 13 feet below the ground; of these 

 five, three were P. spinigera and two were P. martensi. 



Sugarcane. Considerable attention has again been 

 paid during the year to the important subject of cane- 

 borers and to the question of alternative wild foodplants of 

 these. In the past, several different species of borers, all 

 superficially much alike, were mixed up together under the 

 name of Moth Borer (Chilo simplex), which was supposed 

 to attack sugarcane, juar (A . Sorghum), maize and rice. In 

 last year's Report it was mentioned that this " Moth Borer " 

 had been differentiated into four distinct species. Further 

 research during the year has extended this number until 

 we can now discriminate no less than ten forms distinguish- 

 able from one another by morphological differences in their 



