REPORT OF TEE DIVISION OF ENTOMOLOGY AND BOTANY 57 



SESSIONAL PAPER No. 16 



are going to lose their pea crop. There are myriads of this insect in this district. — 

 Samuel Wicks.' 



' Vars, Ont., August 5. — I am sending you a portion of a pea vine which is 

 infested with a small green insect. This insect is playing havoc with the pea crop in 

 some sections. My peas are being destroyed by this insect and some of the neigh- 

 bours' peas are also affected. — D. N. Johnstone.' 



'Plainville, Ont, August 6. — Please find inclosed a specimen of louse that is 

 attacking peas to such an extent that many fields will be scarcely worth harvesting. 

 Will you have the kindness to give their history? Are they likely to continue for a 

 number of years, and will it be safe to sow peas next year? While playing havoc 

 with later peas, they did not attack the early peas. — W. J. Westington, President, 

 Farmers' Institute.' 



In reply to the above, Mr. Westington was informed that the Destructive Pea 

 Aphis was this year being attacked by several important parasites, and owing to this, 

 the injury was being stopped. As to whether it will be safe to sow peas again next 

 year, it was pointed out that this would depend upon the amount of destruction 

 wrought, generally, on the plant lice by the parasites during the autumn. In the last 

 outbreak, in 1889 and 1900, the attack lasted for two years, but it stopped suddenly, 

 just as it began, and in 1901, not a specimen of the insect was seen. 



' Freeman, Ont., August 10. — You will be interested in knowing that we have an 

 outbreak of aphis in the pea fields about here. In most cases the little green lice are 

 so plentiful that no portion of the crop is spared. — Geo. E. Fisher.' 



' Shawville, Que., August 31. — I have a large field of peas which has been 

 destroyed by a large green louse. They do not eat the leaf, but suck all the substance 

 out of the vines, and the plants dry up. The peas were a pretty heavy crop. Would 

 like to know what this insect is and the cure, as my crop is a total failure. My 

 neighbour's peas are also affected. — Andrew Sly.' 



In the Ottawa district the Destructive Pea Aphis was particularly noticed on 

 Sweet Peas in gardens. From observations made after the middle of August, it was 

 noticed that several kinds of parasites were busily at work, and that the plant-lice were 

 thus being reduced rapidly in numbers. Lady-bird beetles and syrphus-flies were 

 doing the larger share of this good work, but two other kinds of parasites which had 

 never before been reared in the Division were present in considerable numbers. One 

 of these belongs to the Cecidomyid genus Aphidoletes, the members of which are 

 well known on account of their habits of preying upon aphids. The other was a small 

 four-winged hymenopterous fly which proved to be an undescribed species, and which 

 has since been described (Canadian Entomologist, March, 1909) as Megorismus 

 fletcheri of Crawford. 



Remedies. — In the report of the Entomologist and Botanist for 1899, the late 

 Dr. Fletcher wrote as follows : — ' When an insect appears in such large numbers as the 

 Destructive Pea Aphis did during the past season, and increases with such rapidity, 

 it is evident that it would be impossible to apply any remedy over such a large 

 acreage as was simultaneously attacked, in most places where the insect occurs; but 

 upon green peas and the flowering Sweet Peas in garden, the ordinary remedies used 

 against other plant lice were found to be quite effective against this one also. Upon 

 the Central Experimental Farm the Horticulturist had the plants sprayed with a 

 tobacco and soap wash made of ten pounds of tobacco leaves in half a barrel of water, 

 the liquid from which was strained off after a few hours, and two pounds of whale- 

 oil soap were added. When the soap was all dissolved water was added to make forty 

 gallons, and the liquid was then applied with a spraying pump. Most of the plant 

 lice were found to be dead two days afterwards, and on such parts of the rows as 

 received two applications, the vines were quite cleared of the insects.' 



In his report for 1901, in speaking of the work of the late Prof. Johnson, he 

 says: 'Many remedies were experimented with by Prof. Johnson, and it was found 



