Black bean aphid

Aphis fabae

1. Identification

• Common name: Black bean aphid
• Scientific name: Aphis fabae Scopoli
• Order: Hemiptera
• Family: Aphididae

2. Pest description

• Apterous adults: Small, oval body; black or brownish‑black colouring; dark and relatively long siphunculi; dark cauda.
• Winged adults: Darkened head and thorax; transparent wings; brownish‑black body; wing venation typical of the genus Aphis.
• Nymphs: Similar to apterous adults, but smaller and with dark‑brown colouring.

3. Main hosts

• Vegetable crops: Bean, broad bean, beet, chard, spinach and other Chenopodiaceae and Fabaceae.
• Ornamentals and wild plants: Various herbaceous species, including Chenopodium spp. and Euphorbia spp.
• Primary woody hosts: Euonymus spp. and Viburnum spp.

4. Symptoms and damage

• Curling and deformation of young leaves.
• Reduction of vigour and growth delay.
• Abundant excretion of honeydew, favouring the development of sooty mould.
• Formation of dense colonies on shoots, leaves and inflorescences.
• Potential for transmission of phytopathogenic viruses in vegetables.

5. Biological cycle

• Species with several annual generations.
• Frequently heteroecious cycle, alternating between woody and herbaceous hosts.
• Parthenogenetic reproduction during much of the year.
• Populations increase rapidly in mild climate and in plants with high vegetative vigour.

6. Monitoring

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

7. Management measures

• Cultural: Removal of heavily infested plants; elimination of alternative hosts; management of spontaneous vegetation.
• Biological: Conservation of beneficials such as Coccinellidae, Syrphidae, Chrysopidae and Aphidiinae parasitoids.
• 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.