Mealy Plum Aphid

Hyalopterus pruni

1. Identification

• Common name: Mealy peach aphid
• Scientific name: Hyalopterus pruni Geoffroy
• Order: Hemiptera
• Family: Aphididae

2. Pest description

• Apterous adults: Oval body, light green to bluish-green; covered by a whitish waxy secretion, giving a “mealy” appearance; short, pale siphunculi; pale cauda.
• Alate adults: Darkened head and thorax; transparent wings; light green body with a smaller amount of wax; wing venation typical of the genus Hyalopterus.
• Nymphs: Similar to apterous adults, but smaller and with a smaller amount of waxy secretion.

3. Main hosts

• Primary host: Peach and other species of Prunus.
• Secondary hosts: Various grasses, including Phragmites spp.
• May alternate between hosts according to the season and environmental conditions.

4. Symptoms and damage

• Curling and deformation of young leaves.
• Reduced vegetative vigour and stunted growth.
• Abundant excretion of honeydew, favouring the development of sooty mould.
• Formation of dense colonies on the underside of leaves and on shoots.
• Potential for transmission of viruses in nearby crops.

5. Biological cycle

• Species with several generations per year.
• Parthenogenetic reproduction during much of the year.
• Frequently heteroecious cycle, alternating between Prunus spp. and grasses.
• Populations increase in mild climates and on plants with high vegetative vigour.

6. Monitoring

• Direct observation of the underside of leaves and young shoots.
• Assessment of the presence of mealy colonies, honeydew and sooty mould.
• Counting of individuals per leaf or per shoot to support decision-making in integrated protection.

7. Management measures

• Cultural: Removal of heavily infested shoots; management of wild vegetation, especially host grasses; improvement of air circulation in the canopy.
• Biological: Conservation of beneficials such as Coccinellidae, Syrphidae and parasitoids Aphidiinae.
• Integrated protection: Intervention only when population levels justify it; preference for selective methods compatible with beneficials.

Bibliographic references

• Blackman, R. L., & Eastop, V. F. (2000). Aphids on the World’s Crops: An Identification and Information Guide. Wiley.
• Blackman, R. L., & Eastop, V. F. (2006). Aphids on the World’s Herbaceous Plants and Shrubs. Wiley.
• van Emden, H. F., & Harrington, R. (2017). Aphids as Crop Pests (2nd ed.). CABI.
• Dixon, A. F. G. (1998). Aphid Ecology: An Optimization Approach. Chapman & Hall.