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Rosy Apple Aphid



P_rosyaphd

Rosy Apple Aphid

Usually appear in

Spring to Autumn.


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Caused By:-     The Aphid Dysaphis plantaginea

Description

Rosy Apple Aphid, Dysaphis plantaginea, is one of several species of aphids that infest apple trees and like every aphid species suck the sap from the leaves and buds. The body of this aphid has a very waxy coating and usually a slight purplish or rosy tinge, which gives it its name. It is the most destructive of the aphid species that feed on apple trees as well as pear and hawthorn. During feeding, this aphid inject their chemicals into the plant which alter plant, as well as fruit, growth, causing deformities. The leaves are severely curled, stunted and eventually turn deep red.
Rosy Apple Aphid nymphs and adults are usually found on the expanding leaf buds and fruit bud clusters. One characteristic feature of this aphid is the congregation of the young about the mother. Each individual mother will have hundreds of its offspring around it even in layers.
The aphid secretion of honeydew causes a black mould to occur on the leaves below the infection. This mould is only superficial and can be washed off, but it does limit the photosynthesis and therefore weaken the tree.
Ants may also be in attendance defending the aphids and moving them to other leaves.
Rosy Apple Aphid overwinters in the egg stage which are laid in the crevices in the bark of larger branches.
In the spring, eggs hatch as the buds start to expand in the green stage.
Newly hatched nymphs feed on expanding buds until they mature into wingless adult females that give birth to live young. Each female produces up to 200 young, which can lead to rapid buildup of large populations.
When the population is large enough winged individuals are produced which mate and fly to a different plant species or secondary host, usually the Dock or Plantain weed.
By late-July, most of the rosy apple aphids have left the apple trees.
In the Autumn more winged forms develop again and return to the primary host (Apple, Pear or Hawthorn) to lay overwintering eggs. The eggs are oval and slightly flattened on the side next to the bark, 0.5mm in length and initially bright yellow which eventually turns shiny black and is usually difficult to see as they are laid in inaccessible places.
Picture by Whitney Cranshaw, Colorado State University, Bugwood.org.
See also these other aphids Aphids, Blackfly, Cypress, Green Spruce, Honeysuckle, Juniper, Lettuce Root, Lupins, Mealy Cabbage, Mealy Plum, Melon Cotton, Peach, Rose, Wooly.


Control

Control depends on proper timing of insecticide applications. Overwintering aphid eggs can be targeted with winter tar wash or insecticidal plant oil wash, although a spray at the pink bud stage, after eggs have hatched, is usually more effective for control.
Systemic insecticides may be more efficient at killing the early stages after the eggs have hatched.
Research has shown that aphids can quickly mutate to become pesticide-resistant. If using organophosphates or carbamates, rotate spraying between two or three different types. Insecticidal soaps is another useful spray.
Encourage beneficial insects like Ladybirds Lacewings, Hoverflies, Spiders and Parasitic Wasps. in the garden These predators eat the aphids and keep this pest to a minimum.
Another problem with aphids is that they can carry viruses and disease to healthy plants.
Aphids also tends to like the young soft leaves which can be exacerbated by using too much nitrogen feeding.



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