lo Jllv. tqij.] /'ropii'^anflii of i'ru'it 7 rccs. 425 



PROPAGATION OF FRUIT TREES. 



{Coiitiiiiitc/ from page 349.) 

 B) C. F. Cole, Orchard Supervisor 



Diseases {continued). 



Black Peach Aphis,| J/ (/;«••>■ Cemsi (Fal)r. ) 

 Green Peach Aphis, Myzm sp. 



The black and green peach aphis are two of the worst insect pests 

 the propagator of the peach and other stone fruits has to contend with. 

 Insects belonging to the family Apludidoe multiply very rapidly by deposit- 

 ing living young ; under certain conditions they propagate by means of 

 eggs. If immediate action is not taken to check their spread when first 

 noticed, they will give trouble, causing serious damage to the seedlings, 

 budded stocks, and growing buds. Like most aphides, these two species 

 (black and green) usuallv attack the under parts of the twigs and shoots 

 first, finallv covering all parts as they multiply. The earliest to make its 

 api)earancp is the black species, which arrivt-s in the 

 autumn or earlv winter, during mild weather. The ('eriod 

 of attack, if uncliecked. t-xtt-iids into the spring, or eaily 

 summer. These in.sects disapi)ear after the first few hot 

 days. The waiter made careful observations during 

 November. 1908, on the habits nf the black aphis. The 

 females of the last spring brood become oviporous. 

 depositing small oval glossy-black eggs behind the buds, 

 in cracks and crevices upon the trees, and upon the roots. 

 The eggs remaining unhatche<l during the hot summer 

 months were hatched in the autumn or earh winter. 

 With the green species, the period of attack is much later 

 than the black. The first appearance is usually in the eggs of black 

 earlv spring when the trees are vegetative, and the young peach aphis. 

 tender shoots and foliage are preferred to the matured + 30. 



twigs. There is verv little doubt that the life history of the green species 

 is similar to that of the black species, i.e., the last brood of females deposit 

 eggs. So far the writer has failed to find any trace of the green aphis 

 eggs, and has not met any person who has. Se\'eral indications warn of 

 a coming attack. With the black species, if the winged in.sects are to be 

 seen in late autumn upon the underside of the foliage, and while the trees 

 are shedding their leaves, it is a sure sign of coming trouble. In the winter, 

 when trees are badly attacked, they have the appearance of being covered 

 lightlv with soot. Another sure sign is ants and flies upon the trees in 

 quest of a sweet liquor which distils from the aphis. It is owing largely 

 to this liquid, which covers the bodv of the aphis, that a wash has to V)e 

 applied with force in order to destroy the pest. 



Young and growing shoots curl when attacked by either species (black 

 or green). If the leaves become crinkled arid curled near the terminal end 

 the presence of green a[)his will be detected upon a close examhiation. 

 Owing to the leaves curling and protecting the insects, the green species 

 is hard to combat : such foliage conditions make it hard to apply a wash 

 that will come in direct contact with the insects, which is necessary if the 

 operation is to be successful. 



74s 1. P 



10 maKe 



f 



