1908 ENTOMOLOGICAL SOCIETY. 119 



The occurrence of the Apple Leaf Hopper, Empoasca mali, LeB., in such 

 enormous numbers was undoubtedly the most notable outbreak of the year 

 in Eastern Ontario. At Ottawa injury was done chiefly to potatoes, although 

 beans and other vegetables were severally attacked. The presence of the 

 insects in destructive numbers was noticed towards the end of June, and 

 the injury continued throughout the summer. These insects, which are pale 

 green in colour, slender, about an eighth of an inch in length when mature, 

 feed on the under sides of the leaves by sucking the juices out of the plants. 

 When they are young and before they have developed wings, they can be 

 destroyed by spraying the infested crop with whale oil soap, one pound in 

 five gallons of water, or with the ordinary kerosene emulsion. Some pota- 

 toes which were sprayed early in July, before the young leaf hoppers acquired 

 their wings, were freed from the pest, and were not since injured to any 

 appreciable extent. The severity of this outbreak has been much aggravated 

 this season by the exceptional drought and heat, which weakened the plants, 

 and made them more than usually susceptible to injury by the insects. 



The Potato Flea-beetle, Eyitrix cucumeris, Harr., was present in 

 potato fields in the district in considerable numbers. On August 21st H 

 was found to be abundant on potatoes on the Experimental Farm, working 

 with the Apple Leaf Hopper, Empoasca mali. This flea-beetle is some- 

 times, in hot dry seasons, one of the worst enemies of the potato. Dr. 

 Fletcher recommends spraying the vines with Bordeaux mixture, as this 

 treatment has given far better results than spraying with Paris green. 



In early August the Destructive Pea Aphis, Nectarophora pisi, Kalt., 

 did severe injury to sweet peas in gardens. The plant lice were present 

 in large numbers and from specimens collected later, a number of parasites 

 of the genus Praon were reared. The parasitized plant lice were rather 

 numerous on the vines. Field peas near Ottawa were also much attacked 

 by this pest, several complaints of very serious injury being received at the 

 Division. 



Other kinds of plant lice were much in evidence during the season. 

 Apple trees were badly infested by the Apple Aphis. Some young trees 

 examined on August 12th were practically covered with the aphides. Some 

 seedlings were sprayed on August 8th with whale oil soap, 1 lb. to 4 gallons 

 of water, and with the ordinary kerosene emulsion, but neither of these 

 mixtures killed all of the insects. The kerosene emulsion did the better 

 work. Vegetable marrows were much reduced in vitality by the attacks of an 

 aphis. Towards the end of the season, Swede turnips, cabbages, and cauli- 

 flowers, were attacked by the Turnip and Cabbage Aphis. Early in October, 

 celery plants were severely injured by plant lice, and many rendered useless. 

 The Woolly Aphis of the Apple and the Woolly Aphis of the Alder were also 

 more than usually abundant. 



Cutworms, as usual, did much harm in some gardens early in the 

 season. At East Templeton, near Ottawa, they destroyed many tobacco 

 plants. Mr. Letourneau, of our office, who visited the locality early in 

 August, reported to me that cutworms had been much complained of by the 

 farmers of the district. A rather interesting occurrence of the Variegated 

 Cutworm, Peridroma saxicia, Hbn., was discovered in one of the greenhouses 

 at the Central Experimental Farm, on August 24th. On September 1st, 

 larvae about | an inch long were brought into the Division. In all about 

 75 larvae were collected, which had been found feeding on Primulas. No 

 other plants were injured. In confinement they grew rapidly and buried 

 on September 12th, 13th and 14th, the moths emerging in the office on 

 October 20th and 22nd. (Fig. 31). 



