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which 1 lb. sodium arsenite dissolved with 8 lb. jaggery [palm sugar] 

 or molasses in 10 gals, water, is mixed. Such collection and destruc- 

 tion should be carried out systematically for three or four years, whether 

 the pest is numerous or not. Once this has been done the infestation 

 will not be severe even in seasons of uncertain rainfall. 



KuNHi Kannan (K.). Pulse Beetles (Store Forms).— Mysore State 

 Dept. Agric, Bangalore, Entom. Ser. Bull. 6, 1919, 31 pp. 18 figs. 

 [Received 19th December 1919.] 



Almost all pulse crops, such as gram, lablab, peas and beans, are 

 liable to infestation by Bruchids. The commonest species found in 

 stores in Mysore is Bruchus (Pachymerus) chinensis. Since the life- 

 history of all the species concerned is very similar, this one only is 

 described in detail. The eggs are laid on the seed, to which they 

 are firmly attached by an adhesive substance. The larva hatches 

 in from 4 to 7 days, according to the season. A remarkable feature 

 of this stage is the presence of a curved, H-shaped, chitinous plate, 

 situated dorsally on the first thoracic segment. The larva upon 

 hatching enters the seed and before beginning excavation, the 

 H-shaped plate is fixed against the egg-shell as a support, the angle 

 at which it is fixed determining the inclination of the head and 

 consequently the part of the hole that the larva works on at a particular 

 moment. Soon after entering the seed the larva casts its skin and 

 is no longer provided mth the chitinous process. It pupates near 

 the seed surface, in which the beetles cut out circular holes for emerg- 

 ence. The life-cycle varies from 19 days to a month and 21 days, 

 the longest period being during the coldest weather. The adults 

 apparently take no food, but mate and oviposit soon after emergence. 

 They have a very marked instinct to reach the surface of stored 

 seeds, whither they arrive from any part of the receptacle, and where 

 they mate, ovipositing only on the top layers of seeds. An experi- 

 ment is described proving that the reason for this upward migration 

 is to get relief from the weight of seed above them. Apparently 

 the survival of the pest from year to year is carried on by a few adults ; 

 these have been captured near stored seeds and also in the field before 

 the crops that they attack are ripe. 



Hymenopterous parasites have been observed to bore through 

 seeds to reach the insect within them ; these include Bncchocida 

 orientalis, Crawf., Bruchobius colemani, Crawf., and an undetermined 

 species. Another enemy is a mite, probably Pediculoides ventricosus, 

 Newp. None of these enemies is an efficient check, however, and 

 it is essential that all seeds should be dried in the sun for three days 

 before storage. 



The remedy usually suggested for infested seed is fumigation before 

 storage or whenever it is found to be attacked. The dose required 

 is 2 lb. carbon bisulphide per thousand cubic feet of space, though in 

 small chambers of a few cubic feet it is usually doubled. If hydrocyanic 

 acid gas is used, the dose for 100 cub. ft. is 1 oz. of 98 per cent, grade 

 potassium cyanide in 1 oz. of sulphuric acid diluted with 3 oz. of water. 

 As neither of these methods is safe for the natives to use, investigations 

 have been made as to the most suitable methods of storage. Since 



