"alight ly swollen in the middle. The posterior three legs 

 end in suckers. There are a pair of eyes. Some of these 

 may be found in the empty egg .=ihel]s. Probably they 

 effect an entry through these and keep track of tlie larva. 

 This enemy is not found at all times and is ])y no means a 

 serious check on the pest. 



Control Measures. 



The remedy universally suggested by Entomologists 

 is fumigation of the seed before storage or whenever the 

 seeds are found to be infested. This consists in exposing 

 the seeds to the fumes of carbon bisulphide or hydrocyanic 

 acid in an air-tight receptacle until the insects are dead. 

 A fumigation chamber can be made at a low cost out 

 of a tin-lined dealwood box. It is provided with a rim 

 in which runs a groove into which the lid fits. Water is run 

 round the channel after the lid is put on. The infested seed 

 is put into the receptacle and carbon bisulphide is placed on 

 the top of the seed in a shallow dish. The fumes of the 

 chemical are heavier than air and descend to the bottom. 

 In doing so the insects and their various stages get killed. 

 The dose is at the rate of 2 lbs. per thousand cubic feet of 

 space but in small chambers of a few cubic feet, it is usually 

 doubled. The seed is removed after two days and 

 stored in a larger receptacle which should also be air-tight 

 to prevent the beetles getting in. Large quantities may be 

 fumigated in rooms; provided these can be made air-tight. 

 Great care has to be taken in the case of the chemical as it 

 is highly inflammable. No light of any kind, not even that of 

 a lighted cigar, should be brought anywhere near the chemical, 

 nor should bottles containing it be placed in the sun or in 

 any other warm place. Otherwise there is danger of serious 

 explosion. Hydrocyanic acid gas is also an efficient fumigant 

 but is even more dangerous to human life. It is prepared 

 by dropping crystals of potassium cyanide into dilute 

 sulphuric acid, the crystals being previously enclosed in 

 thin paper to avoid a too rapid evolution of the gas. This 

 gas is one of the most violent poisons known and immedi- 

 ately the crystals are dropped, the lid should be put on and 

 the operator should withdraw. The dose for a 100 cubic feet 

 of space is the gas produced by dropping one ounce of 

 potassium cyanide (98 per cent grade) into an ounce of sul- 

 phuric acid diluted with 3 fluid ounces of water. For fumi- 

 gating seeds hydrocyanic acid gas is, however, not usually 

 employed. 



