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frozen last year on the late turnips. The parasites of this species were 

 unusually numerous last season. A bacterial disease destroyed great 

 numbers of the last two broods. 



The standard remedy for this insect on small areas has long been white 

 hellebore. This insecticide controls them readily enough but is rather 

 expensive where much has to be used. On large plantations lead arsenate 

 is now largely used ; it is preferred to Paris green, on account of its greater 

 adhering quality. Some growers use the hellebore after the heads of the 

 cabbage are formed, others Paris green or lead arsenate for all applica- 

 tions. Experiments have shown that the danger from the use of these 

 poisons is very slight. The outer leaves which carry most of the poisons 

 are invariably removed, and the inner portion washed. It was estimated 

 from the experiments that from 14 to 20 cabbages would be required to be 

 eaten at once to give a fatal dose of arsenic. The only danger would appar- 

 ently be from poison lodged in holes eaten deep into the heads by the cater- 

 pillars. These holes would not occur, however, if the field had been properly 

 sprayed. 



A poisoned resin wash is sometimes used on cabbages and turnips on 

 account of its great adhering quality. Soap dissolved in the lead arsenate 

 is an advantage in this regard. Whichever poison is used should be applied 

 thoroughly and as often as the caterpillars become at all numerous. 



The Carrot Rust Fly (Psila rosre). This most injurious pest has been 

 troublesome for some time in the Maritime Provinces and in Eastern 

 Quebec, and has recently been reported about Montreal. One grower near 

 the city lost an entire seeding of carrots last year from this cause, and we 

 found a few infested plants, for the first time, on the College farm. 



The Carrot Rust-ny — 1, 5. 7. natural size; 2, 6. 8 enlarged. (Curtis). 



The eggs laid at the base of a plant by a two-winged fly, hatch into 

 maggots, which bore into the root. The young plants are often killed out- 

 right, and later the large roots, apparently but little injured, are rendered 



