RETORT OF TEE EXTOMOLOGIST AXD BOTAMST 



SESSIONAL PAPER No. 16 



The Turnip Aphis (Aphis hrassicce, L.). — The most serious injury was by the 

 Turnip Aphis in New Brunswick and Nova Scotia, concerning which many letters 

 were received. This attack on the turnip crop seemed to be a new experience to most 

 of the correspondents in the Maritime Provinces. Spraying with coal oil emulsion or 

 with whale-oil soap (1 lb. to G gallons of water) at the time the colonies first appear 

 in July and August was recommended, also ploughing the tops down deeply as soon 

 as possible after they are cut from the roots in autumn so as to destroy the eggs. 



Cabbage Worms (Pier is rapce, L.). — The green caterpillar of the imported Small 

 White Cabbage Butterfly has been abundant and troublesome this year in many parts 

 of the Dominion. In British Columbia it has_ spread rapidly over the whole province. 

 The first record of its occurrence there was in 1899 at Kaslo, on Kootenay Lake. Last 

 ■ummer it reached Vancouver Island and appeared in numbers, which were very 

 much greater this year. It was also extremely common in all the older provinces, be- 

 ing frequently referred to as ' the worst enemy of the cabbage.' Mr. C. II. Young, 

 of Ottawa, observed the butterflies in such numbers in the month of June flying over 

 cabbage and turnip fields, that he likened them to a heavy fall of snow. The best 

 remedy, in my experience, for this insect on cabbage, and one which on the Central 

 Experimental Farm has always proved effective, is Pyrethrum Insect Powder, 1 lb., 

 cheap flour, 4 lbs., the whole to be kept for 24 hours in a tightly closed receptacle, the 

 powder to be then dusted over the infested crop by means of special bellows or from a 

 cheese-cloth bag. When, as is frequently the case, these insects attack turnip fields, 

 spraying with Paris green or some other active poison is permissible. This may be 

 done with perfect safety up to September. Two sprayings during the summer are the 

 utmost that will be required, even in a bad season. On smooth-leaved turnips it will 

 be necessary to dissolve a pound of soap in each 25 gallons of water before mixing 

 with the Paris green, or the poison mixture will not adhere to the foliage. On cab- 

 bages, Paris green and other poisons must never be used. The insect powder answers 

 all purposes without any danger, which is not the case with Paris green, because the 

 caterpillars eat channels into the heart of the cabbages into which the poison i3 

 washed. 



The Variegated Cutworm (Pcridroma saucia, Hbn.). — Notwithstanding the 

 plague of this insect on the Pacific coast last year, there was practically no recurrence 



of the trouble in 1901. In two instances 

 only was damage to garden crops reported. 

 These were both by Rev. G. W. Taylor, near 

 Nanaimo, on Vancouver Island, Mr. Dash- 

 wood-Jones of New Westminster, who made 

 observations on this insect for me last year, 

 reports that moths were seen in some num- 

 bers in June, but that no harm was done to 

 growing crops. Mr. J. W. Cockle, of Kaslo, 

 an enthusiastic and careful student of in- 

 sects, kindly sent me a cluster of the eggs 

 laid at Kaslo, in the middle of June, from 

 which a large brood of caterpillars was 

 reared to maturity, all the moths emerging 

 before winter, about the end of August. 

 Mr. Jones gave the following dates from his 

 notes which add somewhat to the life history 

 of the species : — ' The first specimen I saw 

 of the moth of P. saucia was on May 20. The eggs hatched on May 30. The last date 

 I saw any moths of the spring brood was on June 13. At the same time I found eater- 



Fig. 7. — Variegated Cutworm ; a, cater- 

 pillar ; d, moth : b, c, bead and seg- 

 ment of caterpillar. 



