Tuber Moth
Phthorimea opercullella
Causative agent
The potato tuber moth is an important parasite in hot regions, particularly the Mediterranean basin.
The adult is a small grey moth with a wingspan of 10-15 mm, with fringed wings, which lays eggs in the stems, sprouts, tubers or in the soil.
An entire generation lasts 20 to 30 days (at 30°C) and there can be up to 10-12 generations per year.
The larvae appear on average one week after laying. Larval development lasts two weeks under favourable conditions (temperatures around 25°C).
Pupa-shells are then formed on the tubers bags and leaves, as well as on the walls of the storage premises. These pupa-shells release adults after one week.
The tuber moth develops preferentially on potatoes and tobacco, but can also be found on other members of the nightshade family: tomato, aubergine, nightshade, etc.
Description of symptoms on crops
• On the foliage: damage to leaves and the leaf stalks by perforation and drilling which can weaken the plants. Grey felting on the surface.
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• On the tuber: caterpillars dig tunnels into the tubers, lining them with silk thread and expelling their blackish excrement outside. Other pathogenic agents can collect in these tunnels and cause rotting of the tubers.
Control
- Destruction of contaminated tubers;
- Long rotation;
- Avoid very broken up or cracked soil, etc., favourable for egg laying in the tubers;
- Early harvesting;
- Disinfecting premises;
- Treating the crop with insecticides.
