i9i i.] Aphides, or Plant Lice. 



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preceding (b) the winged females. These winged females are 

 black or black with a brownish tinge ; the shanks and middle 

 joints of the antennae are yellowish ; the wings are yellow at 

 the base, greenish in front, and have brown veins. These 

 females produce live young, (c) Wingless females found in 

 autumn and resembling the females of (a) ; the females of (c) 

 lay eggs, (d) Males, appearing late in the season; they have 

 wings, and are black or black-brown in colour. 



Life-History . — The wingless females of the early part of the 

 year are found on the bean tops, and give rise to live young. 

 Multiplication is rapid, and ultimately winged females appear 

 which spread the infestation to other beans and to different 

 food plants. In the autumn, with the appearance of the 

 males and egg-laying females, fertilised eggs are laid on the 

 plants to which the Aphides have migrated. 



Treatment. — (1) The infested tops should be cut off and 

 burnt. This should be done early. (2) The beans should 

 be sprayed with soft-soap and quassia. Dissolve 5lb. of soft- 

 soap in 100 gallons of soft water; boil 6 to 81b. of quassia 

 chips, and add the extract to the 100 gallons of wash. 



The Cabbage Aphis (Aphis brassicce, Linn.).— In the case 

 of this species, infested leaves drained of their sap become 

 yellow and bleached. Blistered patches show, and under 

 these the Aphides are found. As the numbers increase the 

 pests are found both on the upper and lower surfaces of the 

 leaves. 



The wingless viviparous females have their bodies covered 

 with a mealy secretion that gives them a white appearance and 

 masks the grey-green colour of the body; dark spots are 

 present on the upper surface ; the antennas are green or yellow- 

 green with dark tips ; legs and eyes are dark-brown or brown- 

 black ; the cornicles or tubes on the back are short and dark- 

 brown ; the young, until the mealy secretion appears, are 

 bright yellow or yellow-green. 



When the mealy secretion is removed the winged viviparous 

 females are seen to have the front part of the body black, and 

 the hind part yellow-green ; legs and cornicles are dark-brown. 



The males are green with black antennas, and the cornicles 

 are dark at the base. 



3 M 



