Anyone who has tried to grow vegetables will know that sooner or later the plants are going to receive some unwelcome attention from aphids ~ the menace of the vegetable garden. Aphids can be among the most destructive insect pests on cultivated plants in temperate regions. The damage they do to plants has made them enemies of farmers and gardeners the world over.
From a zoological standpoint however, they are a highly successful group of organisms, due partly to their ability to reproduce asexually.
About 4 400 species are known, all included in the family Aphididae. And they are still active during winter.
Aphids are small, soft-bodied insects with long slender mouthparts that they use to pierce stems, leaves, and other tender plant parts and suck out fluids. They have long legs and antennae and may be green, yellow, brown, red, or black, depending on the species and the plants they feed on. A few species appear woolly or waxy, due to the secretion of a waxy white or grey substance over their body surface. Many aphid species are difficult to distinguish from one another.
Most species have a pair of tube-like structures called cornicles projecting backward out of the hind end of their body. The presence of cornicles distinguishes aphids from all other insects.
Almost every plant has one or more aphid species that occasionally feed on it.
Check your Plants Regularly
Smallholders should take special note of the fact that some aphids transport viruses and disease as they move from one plant to another.
Not only are aphids the menace of the vegetable garden because they eat plants. Winged aphids carry a troublesome virus known as the Barley Yellow Dwarf Virus or BYDV and farmers need to know when these aphids are active in an area. BYDV is a worldwide virus disease of our most important grasses, including wheat and maize.
Check your plants regularly for aphids ~ at least twice a week when plants are growing rapidly, in order to catch infestations early. Many species of aphids cause the greatest damage in late spring when temperatures are warm but not hot. For aphids that cause leaves to curl, once aphid numbers are high and they have begun to distort leaves, it’s often difficult to control these pests, because the curled leaves shelter aphids from insecticides and natural enemies.
Many aphid species prefer the underside of leaves, so turn leaves over when checking for aphids. On trees, clip off leaves from several areas of the tree.
For some tips on how to prevent and treat aphids, click here.