Plum leaf-curling aphid

Brachycaudus helichrysi 

1. Identification

• Common name: Leaf‑curling plum aphid
• Scientific name: Brachycaudus helichrysi Kaltenbach
• Order: Hemiptera
• Family: Aphididae

2. Pest description

• Apterous adults: Small, oval body; light‑green to yellowish‑green colouring; short and dark siphunculi; light cauda; presence of slight dark spots on the abdomen.
• Winged adults: Darkened head and thorax; transparent wings; yellowish‑green body; wing venation typical of the genus Brachycaudus.
• Nymphs: Similar to apterous adults, but smaller and with more uniform colouring.

3. Main hosts

• Primary host: Plum tree and other species of Prunus.
• Secondary hosts: Various herbaceous Asteraceae, including Helichrysum spp.
• It may alternate between hosts depending on the season and environmental conditions.

4. Symptoms and damage

• Curling and deformation of young leaves.
• Reduction of vegetative vigour and growth delay.
• Formation of dense colonies on shoots and tender leaves.
• Excretion of honeydew, favouring the development of sooty mould.
• Potential for transmission of viruses associated with Prunus spp.

5. Biological cycle

• Species with several annual generations.
• Parthenogenetic reproduction during much of the year.
• Frequently heteroecious cycle, alternating between Prunus spp. and herbaceous Asteraceae.
• Populations increase in mild climate and in young, vigorous shoots.

6. Monitoring

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

7. Management measures

• Cultural: Removal of heavily infested shoots; cleaning pruning; elimination of herbaceous alternative hosts.
• Biological: Conservation of beneficials such as Coccinellidae, Syrphidae 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.