Reports to the Board of Agriculture. 33 



must be put in the earth between the pLants. Care must be taken, 

 as it is of an inflammable nature and the fumes are also poisonous. 



(ii) Trapping largely employed for wire-worm consists of placing 

 pieces of carrot, mangel, beetroot or turnips in the ground, and taking 

 them up every few days and collecting the wire-worm that are 

 feeding upon the "bait." Millepedes may also be caught in this 

 way, but for them large hollow, more or less rotten, roots form the 

 best trap. It has also been found that the small millepedes {Jidus 

 pulcliellus) may be caught in numbers by placing cabbage leaves 

 soaked in a solution (1 oz. to the gallon of water) of Paris green 

 on the ground. The millepedes come to the surface at night and 

 feed upon the leaf and are so poisoned. 



Bisulphide of carbon treatment is best ; failing that, some good 

 may be done by trapping by means of ground bait. 



Directions for the Employment of the Gas 

 Treatment under Glass. 



Several enquiries ha\'e been received concerning the destruction 

 of greenhouse pests. 



Various methods of fumigating plants under glass are employed, 

 such as sulphur fumes and tobacco smoke. Neither of these are as 

 good as the employment of hydrocyanic acid gas. For Aphides, 

 Ked Spider, and Wood Lice the following quantities are necessary : 

 2 ozs. of cyanide, 4 ozs. sulphuric acid, 7 ozs. of water per 1000 

 cubic feet of space. Proceed as follows : Pour the water into a jar, 

 then add the acid to the water. Wrap up the cyanide in a piece of 

 blotting-paper and drop it into the jar of acid and water from outside 

 the house. This can be done by tying the cyanide bag on to a stick 

 with a longish piece of string, then close the door or window. Leave 

 the house shut up for at least three-quarters of an horn-, then open all 

 doors and windows to ventilate freely ; be careful not to enter the 

 house for at least an hour after the doors and windows have been 

 thrown open. Fumigate at dusk and when the foliage is dry. The 

 temperature must not be above G0° F. The best temperature is 

 50^ F. ; above 60^ F. the foliage gets scorched, as it also does if you 

 fumigate in bright light. If the house is more than 10,000 cubic 

 feet two jars would be necessary, but up to that size one is ample. 



The result of one experiment may be quoted here. Greenhouse, 

 2,000 cubic feet, containing Chrysanthemums in full bloom, severely 

 infested with Green Fly. Cyanide 3^ ozs., acid 5 ozs., water 9 ozs. 

 Temperature 50° F. Time 25 minutes. 1 hour after sunset. 



D 



