Currant-lettuce aphid

Nasonovia ribisnigri

1. Identification

• Common name: Lettuce or currant aphid / Green lettuce aphid.
• Scientific name: Nasonovia ribisnigri Mosley
• Order: Hemiptera
• Family: Aphididae

2. Pest description

• Apterous adults: Oval body, light green to yellowish-green; relatively short and dark siphunculi; pale and well-developed cauda.
• Alate adults: Dark head and thorax; transparent wings; yellowish-green abdomen.
• Nymphs: Similar to apterous adults, but smaller and paler.

3. Main hosts

• Primary host: Currant bush.
• Secondary hosts: lettuce and other cultivated and wild Asteraceae.
• It is one of the most important aphid species on lettuce, especially in greenhouses.

4. Symptoms and damage

• Rolling and deformation of young leaves.
• Presence of dense colonies on the underside of the leaves.
• Excretion of honeydew, favouring sooty mould.
• Reduction of vigour and growth delay.
• Relevant indirect damage due to virus transmission, including lettuce mosaic virus.
• It may compromise commercial quality, especially in leaf crops.

5. Biological cycle

• Holocyclic and dioecious species, alternating between Ribes spp. (primary) and lettuce/Asteraceae (secondary).
• It overwinters as an egg on the primary hosts.
• The first generations appear in spring, then migrating to lettuce and other Asteraceae.
• In greenhouses, it may behave as anholocyclic, with continuous parthenogenetic reproduction.

6. Monitoring

• Direct observation of the underside of the leaves.
• Counting of individuals per plant or per leaf.
• Assessment of the presence of honeydew and natural enemies.
• Frequent monitoring in greenhouses due to the rapid population growth.

7. Management measures

• Cultural: Removal of heavily infested plants; management of wild vegetation; avoid excess nitrogen; improve ventilation in greenhouses.
• Biological: Conservation of beneficials such as Coccinellidae, Syrphidae, Chrysopidae and Aphidiinae parasitoids.
• Integrated protection: Intervention only when necessary; preference for selective products compatible with beneficials; special attention to protected crops.

Bibliographic references

• 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.
• Bartholomew, J. (1999). “Aphids on Lettuce.” In: Insect Pests of Vegetables. CRC Press.
• Dixon, A. F. G. (1998). Aphid Ecology: An Optimization Approach. Chapman & Hall.