191 



EXPERIMENTAL FARMS 



3-4 EDWARD VII., A. 1904 



the eggs, in which form they pass the winter. At that time the plant-lice cluster on 

 the buds to such an extent as to almost hide them. With the rapid expansion of the 

 foliage, they are soon lost sight of, and it is very seldom that serious injury results 

 from their presence. Late in the autumn, when they come back again to apple trees 

 after passing some time on grasses and fall wheat, they are again found in large num- 

 bers upon apple trees, where they lay their eggs. In British Columbia, this insect 

 is one of the most destructive orchard pests the fruit-grower has to deal with, and 

 treatment of infested trees is frequently a necessity. 



It may also be noted that, although the Apple Aphis was troublesome last season 

 in many parts of the Pacific province, Mr. Venables expressly states that the Apple 

 Aphis was less abundant than usual at Vernon, although one might have expected 

 it to have appeared in great force, judging from the large number of eggs laid in 1902. 

 These, however, for the most part failed to hatch last spring. The Apple Aphis is a green 

 plant-louse, having the head, the eyes and the thorax black. The head is pointed in 

 front, and the prothorax has lateral tubercles. The antennae are shorter than the body. 

 On comparing this species with the Grain Ai:»his, which very much resembles it, the 

 most striking differences are that in the latter species the eyes are reddish, the head 



and thorax brown and the head not pointed in front. The 

 antenna?, which are a little longer than the body, are also 

 borne on distinct frontal prominences. A remedy which 

 answers well for the Apple Aphis, is to spray the infested 

 trees thoroughly with whale-oil soap, one pound in six gal- 

 lons of water, or with a tobacco and soap wash made by 

 soaking ten pounds of tobacco leaves in hot water for a 

 few hours, then straining off the liquid and adding two 

 pounds of whale-oil soap. Stir imtil ail is dissolved and 

 fill up to make 40 gallons. If this wash is applied as a 

 spray two or three times at short intervals, little difficulty 

 will be met v/ith in destroying the Apple Aphis 



The injury to apples referred to above resembles very 

 closely that of the small British Columbia Apple-fruit 

 Miner (Argyrcsikia conjugella, Z.), as shown at fig. 15. 



Fig. 15. — Section of Apple 

 showing distortion of 

 outline. 



The Plum Aphis (Aphis prunifolii, Pitch) was mentioned by correspondents seve- 

 ral times during June, and trees infested were sprayed prom-ptly with whale-oil soap 

 or the tobacco and soap wash with good effect. In British Columbia an allied species, 

 Ilyalopterirs pruni, Ps.b., was reported by Mr. E. P. Venables, of Vernon, B.C., as being 

 in greater numbers than for several years past. The insect was also observed at several 

 other places in British Columbia, both on the mainland and in Vancouver Island. 



The Cherry Aphis (Myzus cerasi, Pab.). — This is a black plant-house, which fre- 

 quently appears in large numbers early in spring and clusters around the young fruit 

 and along the stems of the fruit and leaves, sucking the sap and doing much harm. 

 The eggs are laid upon the twigs during tlie autumn, the young plant lice not hatch- 

 ing until the following spring. This plant-louse has done a considerable amount of 

 harm in western Ontario for several years, and during the past summer, although in 

 most places it disappeared early in June, in others much loss resulted from its attacks. 

 Mr. J. B. Pairbairn writing from Bowmanville, Ont., says : ' I have two English cherry 

 trees that for years have had their crop ruined by this pest ; two seasons ago I planted 

 out three Montmorencys, and I find they also are covered with tliese insects. It seems 

 almost impossible to destroy them without injuring the trees.' The Cherry Aphis is 

 one of the class known as Black Plant-lice, and it is a remarkable fact which has not 

 been account:^d for, that all of these dark coloured plant-lice are much harder to kill than 

 those which are of a green or light colour. Por the Apple Aphis, Hop Aphis and other 

 green-coloured species, one pound of whale-oil soap in 8 or 10 gallons of water is suf- 



