Mealy Plum Aphid

Hyalopterus pruni

Mealy Plum Aphid

Hyalopterus pruni 01 by AfroBrazilian (CC BY-SA 3.0)
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A photograph of Hyalopterus pruni mealy plum aphid on the back of a grass/ reed leaf
Hyalopterus pruni 01 by AfroBrazilian (CC BY-SA 3.0)
1 of 5
Deal with aphids organically: Method 4
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Deal with aphids organically: Method 4
Deal with aphids organically: Method 3
Deal with aphids organically: Method 3
Deal with aphids organically: Method 2
Deal with aphids organically: Method 2
The mealy plum aphid is a soft-bodied sap-sucking insect that's often seen in large aggregations on the infested host plant. These aphids are small (2mm), pale green and seen often beneath the leaves of Plums, damsons, greengage and sloes. These are active from mid-summer and they excrete large amounts of sticky-sugary secretions over the surfaces of infested plants. This can facilitate the growth of mould, which in large amounts can prevent sufficient photosynthesis for growth and repair. Winged morphs become more apparent throughout the summer, migrating to grasses and reeds for further breeding.


These insects excrete a sugar-concentrated liquid known as honeydew, which can facilitate the growth of black sooty mould.
An abundant resource for predatory insects during summer.


Adult Hyalopterus pruni are variable. They are described as a pale blue-green with a powdery white coating, this can make it appear grey or light green. Some adults are pink! They can be winged or wingless, depending on the time of the cycle. Nymphs are typically smaller than adults. They also lack wings and normally are pale green or yellow.


Dense groupings of the aphids can rapidly develop on soft young tips, flowering stems and the underside of the younger leaves. The aphids often attract ants, which collect the sugary honeydew that aphids excrete. When the back bean aphid attacks broad beans the plants pod formation will be reduced and yields affected.











These aphids are distributed worldwide.

Biological treatment

The introduction of ladybirds, hoverfly larvae, lacewing larvae and several parasitic wasps in a garden situation will reduce numbers. Recent research has shown the benefits that are provided by earwigs. Providing shelter for insects like earwigs in the garden may help to increase earwig numbers. Unfortunately, aphid infestations can often build up on plants before the natural enemies are active in sufficient numbers so natural predators will only have limited control success. It's thought most infestations are tolerable, with yields seldom impacted. However, if you believe your infestation is heavy, please read on to our chemical alternatives.

Chemical treatment

Only smaller plants can be effectively treated. Chemical treatments are unsuitable for plum trees. Overwintering eggs within the nooks of bark can be treated with plant oil winter washes - the whole area must be covered for good control. Spring sprays aren't required if this option is sought. Insect sprays are ineffective when the leaves have curled. If a more persistent chemical option is sought, check with your local garden centre and please take care to follow the manufacturers' instructions. Check with your local regulating body for guidance on active ingredients and their authorisation for use. Alternatives available for home use vary in the degree of persistence and strength. These include organic sprays containing natural pyrethrums; winter washes containing natural plant oils; and lastly, the more persistent chemicals which incorporate synthetic pyrethroids. Plants that are in flower should never be sprayed due to the danger they pose to pollinators.


These insects are attracted to apricot, peach, plum, reed grasses and cattails.

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