Pear-bedstraw aphid

Dysaphis pyri

1. Identification

• Common name: Pear aphid / Pear‑grey aphid.
• Scientific name: Dysaphis pyri Boyer de Fonscolombe
• Order: Hemiptera
• Family: Aphididae

2. Pest description

• Apterous adults: Rounded body, grey to brownish‑violet colouration, often covered by waxy secretions; short, dark siphunculi.
• Winged adults: Dark head and thorax; transparent wings; lighter abdomen.
• Nymphs: Similar to apterous adults, but smaller and with a lighter colouration.

3. Main hosts

• Primary host: Pear tree.
• Secondary hosts: Various species of Plantago spp., where it completes part of the cycle.

4. Symptoms and damage

• Curling and deformation of young leaves, forming characteristic pockets.
• Deformation of shoots and reduced growth.
• Direct damage to young fruits, which may become deformed.
• Excretion of honeydew, favouring sooty mould.
• Relevant economic losses in susceptible orchards, especially in early spring.

5. Biological cycle

• Holocyclic and dioecious species, alternating between pear tree (primary) and Plantago spp. (secondary).
• Overwinters as an egg on the pear tree.
• The first generations develop in spring, causing the most severe damage.
• In summer, it migrates to Plantago spp., returning to the pear tree in autumn to lay winter eggs.

6. Monitoring

• Observation of curled young leaves in spring.
• Counting of colonies on terminal shoots.
• Assessment of the presence of nymphs and adults on the underside of the leaves.
• Early monitoring is essential due to the rapid development of the first generations.

7. Management measures

• Cultural: Removal of heavily infested shoots; management of spontaneous vegetation, especially Plantago spp.; improvement of canopy ventilation.
• Biological: Conservation of beneficials such as Coccinellidae, Syrphidae and Aphidiinae parasitoids.
• Integrated protection: Intervention directed at the first generations; preference for selective products compatible with beneficials.

Bibliographic references

• Blommers, L. H. M. (1994). “Aphids on pear.” In: Aphid Pests of Fruit Trees. CABI.
• Blackman, R. L., & Eastop, V. F. (2000). Aphids on the World’s Crops: An Identification and Information Guide. Wiley.
• van Emden, H. F., & Harrington, R. (2017). Aphids as Crop Pests (2nd ed.). CABI.
• Hull, L. A., & Beers, E. H. (1990). “Aphids.” In: Armored Scale Insects and Other Pests of Apple and Pear. Michigan State University Press.