Aphids

Superfamily: Aphididae

Description

Aphids are small -2-4 mm long-, soft-bodied insects that use their piercing-sucking mouthparts to feed on plant sap. Aphids are common garden pests that usually occur in colonies on the undersides of tender terminal growth. They have hundreds of species and almost as many colours as green, yellow, orange, gray, black, or white. Adult aphids may or may not have wings.

Life Cycle

The life cycle of the aphid is complicated. Wingless females reproduce without fertilization and produce living young nymphs as opposed to eggs which occur in most other insects. They mature in 7 to 10 days and then are ready to produce live young. Usually, all these live young are females, and each can produce 40 to 60 offspring.

The process is repeated several times, resulting in a tremendous population explosion. Eventually, when the infested plants become overcrowded with offspring, some offspring develop into winged females and fly to new plants to begin a new colony. In late summer both males and females are produced. They mate and lay eggs that survive the winter. In warm climates, there may be no need for an overwintering egg stage, and generations occur continuously.

Damage

Saliva injected into plants by aphids may cause leaves to pucker or to become severely distorted, even if only a few aphids are present. Heavily-infested leaves can wilt or turn yellow because of excessive sap removal. Feeding on flower buds and fruit can cause malformed flowers or fruit. Also, aphids produce sugary liquid waste called “honeydew” which causes the growth of a fungus called sooty mold, turning the leaves black. On the other hand, honeydew can attract other insects such as ants, that feed on the sticky deposits. Even worse, many species of aphids carrying viruses on their mouthparts and are very important vectors of plant viruses.

Control

Advice

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