Snowy Fly
(Aleyrodes proletella). A small, four-winged Fly, that lives on the lower leaves of Cabbages, often in such numbers as to cause the leaves to show yellow or pale patches, or even to wither and die, so that the plants are much injured where the attack is severe. The Snowy Fly is nearly related to Aphides, and resembles them in general form and in size, the length not exceeding 1/16in., and the spread of wings being about 1/8in. It has, however, no honey-tubes, and is snowy-white in colour, owing to its being covered with a white, powdery coat. Below this coat the head and the thorax are black, marked with yellow; the abdomen is yellow or rosy-red, and the front wings are marked with a dusky spot near the middle. On the head is a beak, as in Aphides, which is inserted into the leaf, and serves for sucking in the sap. The female insects place their eggs in patches on the leaves; and the young, on emerging, scatter themselves over the leaves, which they pierce with their suckers, and to which they adhere closely. Each then becomes covered with a white scale, bearing two yellow spots; and below this it becomes a pale pupa, with red eyes. The whole metamorphosis occupies nearly four weeks. Remedies. The most reliable is to remove and burn infested leaves. A remedy less to be trusted is throwing them into a liquid manure tank, or into a farmyard, where the trampling under foot destroys the larvae and pupae. Dusting the plants with soot or ashes, and syringing with tobacco-water, have also been recommended.