REPORT OF THE ENTOMOLOGIST AXD BOTANIST. 195 



The plant-louse which does most harm to the Swede turnips in Canada, is the same 

 species which is also sometimes destructive to cabbage and is better known as the Cab- 

 bage Aphis. It does not usually appear on turnips until August, and is stated by many 

 correspondents to be worst in dry years. There is a general impression that nothing 

 can be done to prevent injury, and as a consequence these insects are, as a rule, left un- 

 molested and a great loss sometimes occurs. 



Remedies. — At the time these plant-lice first appear in fields, they are nearly always 

 found in patches of restricted area. These should be looked for at the time the turnips 

 are hoed and thinned, when good service may be done by simply hoeing out the infested 

 plants and, having pulled some earth over them with the hoe, then pi-essing it down 

 firmly with the foot. When the plant-lice are too numerous for this simple treatment, 

 the plants should be promptly sprayed with a knapsack sprayer, using as an insecticide 

 kerosene emulsion, 1 part to 9 of water, or whale-oil soap, 1 pound in 8 gallons of water. 



Root Maggots in turnips are seldom complained of in the West, where radishes are 

 grown to the greatest perfection. Occasionally, however, there is a local outbreak 

 of these troublesome insects. Mr. T. N. Willing, of Sylvan Glade, near Olds, Alta., 

 sends specimens of the Cabbage Root-maggot {Phorhia hrassicce, Bouche), which, he 

 says, " are from a larva about f of an inch long, whitish with black hooks at end, which 

 feeds in the Swede turnips. From one small turnip I found about 75 had entered the 

 sand in which I had placed the turnip, and were in the pupa form. I inclose some 

 •with the flies. I had the turnip in the house about three weeks before these flies hatched 

 out. Quite a large proportion of my turnips were damaged by this fly, I suppose it 

 would be well to change the location of my turnip patch next season." 



There were, as usual, inquiries from several other parts of Canada where the maggots 

 of this fly are known to occur injuriously, one of the worst occurrences being along the 

 shores of the lower St. Lawrence in the province of Quebec, where sad havoc was wrought 

 in the gardens of the poor fishermen, who have to depend to a large measure on the 

 products of their gardens. An account of this outbreak was sent to me by Dr. A. 

 Mackenzie Forbes, of Montreal. 



Remedies. — A sure remedy for these troublesome maggots is still much needed. 

 Every year they are the cause of much loss in crops of great importance to a large 

 number of people, such as cabbages of all kinds, turnips, radishes, onions, and sometimes 

 beans and corn. A great many experiments have been tried with the object of discove- 

 ring something of use. Many materials give partial iaimunity in ordinary seasons, but 

 in iiad years everything seems after a time to fail. 



With onions and radishes, kerosene emulsion of the ordinary strength, 1 to 9, or 

 carbolic soap-wash sprayed along the rows once a week gave tolerably good results, 

 indeed some of the best results of many applications tried. The carbolic wash was 

 made as follows : Dissolve 2 quarts soft soap in one gallon of boiling water, add 1 

 pint crude carbolic acid ; when required for use, take 1 part with 50 of water. The 

 most satisfactory application, but only to a small measure and early in the season, was 

 White Hellebore or Pyrethrum powder dusted dry along rows of ralishes at the time 

 they appeared above ground and once a week afterwards. This is only applicable on a 

 fimall scale. Experiments with kainit showed that this material assisted the plants very 

 much in outgrowing injury, which in the case of cabbages is of very great importance. 

 Kainit has also insecticidal value ; but not, I think, to the degree which is claimed 

 for it. It was tried (i.) broadcasted along the rows of onions and radishes, (ii.) sunk in a 

 drill close to the rows and (iii.) in solution. When sunk in a drill it seemed to give better 

 results than with the two other methods. In solution, when used strong enough 

 to affect the maggots, it also injured the bulbs of the radishes, causing black spots, 

 which afterwards rotted. Onions, however, were not injured, and the treated rows 

 were decidedly better than the untreated. Experiments with cabbages showed that the 

 best results were secured with a mixture of 4 ounces of kainit and 4 ounces of hellebore 

 in 2h gallons of water, half a teacupful being poured round the base of each cabbage 

 after" pulling away the soil down to the true roots and applied in the third week of June, 

 just as soon as the maggots were detected. 

 86— 13^ 



