Basic info:
Aphids attack nearly all species of plants. When leaves are attacked by aphids, damage often appears first as spotty yellow discolorations, usually on the undersides of leaves; the leaves may later dry out and wilt. Some aphid species form galls or cause distorted, curled, or deformed leaves. The galls are swellings of plant tissues that are usually globular or spindle-shaped, with mouth-like openings. Many galls turn brown and are considered unsightly. Each gall or deformed leaf may contain numerous aphids in all stages of development. Aphids attached to other plant parts such as stems or twigs may cause stunted growth, early leaf fall, or twig mortality, but aphid damage very rarely kills the plant. The life cycle of many aphids is somewhat unusual and complex. Most species overwinter in the egg stage on the host plant; the eggs hatch into young female nymphs (stem mothers) in the spring, and subsequently reproduce without mating (parthenogenetic reproduction), giving birth to living young. Several generations of aphids may breed in this manner during the summer, but only females are produced. The first one or two generations may be wingless, but eventually a winged generation may be produced that can migrate to new plants. Toward the end of the summer season a new generation of aphids may return to the original host plant to produce both males and females. After they mate, the females lay eggs on the host plant for the overwintering stage. Many aphid species secrete honeydew from the anus; this sweet, sticky substance consists mainly of excess sap ingested by the insect and contains sugars and waste materials. At times, enough honeydew may be secreted to cover not only the aphid infested foliage but also objects below the affected tree or shrub. After a time a black, sooty fungus that grows on honeydew gives everything it has covered a dirty gray appearance. Because of its sweetness, the honeydew attracts other pests such as flies, wasps, and especially ants, whose presence may be the first visible sign of an aphid infestation (honeydew is a favorite food of many ants, which may protect the aphids from predation).
What We Recommend:
1) Introduce Lady-Bird Beetles and birds as natural predators of the Aphids
2) Spray the tree with a pressured water hose to knock any aphids down from the tree and clean some of the honeydew off.
3) Insecticides registered for control of aphids include: malathion, diazinon, dimethoate, or permethrin.
Trees/Shrubs Effected by Aphids: Deciduous, Coniferous, All Shrubs.
Government Informational Source Link:
https://tidcf.nrcan.gc.ca/en/insects/factsheet/5371
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