158 PROCEEDINGS OF THE SECOND ENTOMOLOGICAL MEETING 
to catch the crabs and the work would be all the easier, considering the 
limited sizes of the holdings. Again in Kason and Nayon and the rainy 
weather crab-hunting would be child’s play as these creatures leave 
their burrows and come to the surface in the evenings and occasionally 
in the mornings. When they are not found on the surface, attempts 
may be made to pick them out from these holes as suggested above. 
It must however be borne in mind that it is by means of co-operation 
and simultaneous action only that the pest can be checked. The crabs 
collected should not be thrown aside, but stored in an earthen jar or 
any other convenient vessel and allowed to rot. They then make an 
excellent manure. Like cray-fish, the crab, when boiled, mixed with 
meal and allowed to dry makes an extremely valuable egg-producing 
food for poultry. In Japan the following measures are resorted to :— 
(1) handpicking, (2) protection of the crops by surrounding the field 
with a straw mat, and (3) the use of the waste product in the tobacco 
factory (the midribs of the tobacco leaves) as manure and also into the 
burrows of the crabs. The second measure is, from its very nature, 
hardly practicable in Burma on account of extensive paddy fields. 
Much waste product of tobacco may be available from the local cigar- 
rollers and can be easily used as manure as well as into the burrows of 
the crabs. This measure deserves a trial in this province. It is hkely 
to impart vigour to plants and also kill the crabs in good numbers. 
In America, the following three methods of poisoning cray-fish have 
been devised which would no doubt succeed in case of our land crabs, 
but they are attended with serious disadvantages which would hardly 
bring them into the sphere of practicability im this country. 
(1) Carbon Bisulphide is used in the burrows which are then imme- 
diately closed and its fumes kill the animals. The use of this stuff on 
a field-scale is not possible in this country for two reasons. First it 
is likely to involve greater expenditure than the collection even by 
hired labour would, and secondly, being a dangerous inflammable sub- 
stance, it cannot be safely trusted in the hands of ignorant cultivators. 
(2) Chloride of Lime. An ounce of a solution of Chloride of Lime 
(of the streneth of one pound to 3 gallons of water) was found sufficient 
to kill the cray-fish in their holes. It is cheaper than Carbon Bisulphide 
but the time required to make the solution and haul it to the field prac- 
tically offsets its cheapness and therefore it 1s said to have little or no 
advantage over Carbon Bisulphide. 
(3) Calcium Carbide is said to be effective and useful on account of 
the ease of its application but the cost prohibits its use in large quan- 
tities. It is used only in burrows that are nearly perpendicular, as. 
