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Phthorimaea operculella (Zeller)
Gnorimoschema operculella

Insecta, Lepidoptera, Gelechiidae .

Potato tuberworm, Potato split-worm

Description, Biology, Life Cycle, Damage, Common Names, Images

- Adult: 10 to 12 mm wingspan. Grey abdomen, antennae almost as long as the body. Very narrow wings, the anterior pair yellowish grey sprinkled with little black spots; the grey hind wings bear long bristles.
- Egg: oval, smooth, milky white with a pearly sheen.
- Larva: 10 to 12 mm, rosy white, brown black head and prothorax, a few black points with a small number of bristles on each segment.
- Cocoon: Very narrow, 12 mm long, whitish.

- The caterpillar develops generally in potato tubers (*) , but also occurs in the fruit, stem and even in the leaves of Solanaceae, particularly egg-plant, tomato, tobacco.
- Adult: ifespan about 1 week. It feeds on nectar or dew; it flies little, having a jerky zig-zagging flight. Mating begins 24 hours after it has emerged. The average fecundity is about a hundred eggs.
- Eggs: Laid singly or in small clusters in the cracks and indentations of the eyes of stored potatoes, of leaves or of fruits. Embryonic development lasts 3 to 6 days.
- The caterpillar moves about rapidly and penetrates the tuber at the level of a crack; it makes a small silken sheath and moults. It then forms a gallery which it coats with silk threads and ejects its frass to the outside. When the caterpillar emerges on leaves, it forms a gallery and then penetrates the petioles, the stems or other leaves. After 15 to 20 days, its growth finished, it leaves the plant and pupates in various situations: on potato bags, walls, etc.
- Length of pupal stage: 10 to 30 days depending on climatic conditions.

[R]Life Cycle
- About 6 generations per year in Mediterranean regions.
- Hibernation occurs in the egg, caterpillar or adult state, often in potato seed storehouses. Generally, the moths appear from April to October, the generations overlapping each other. All instars may occur together. Larval development is interrupted by temperatures below 10░C.

- In the event of a heavy infestation, 5 to 6 larvae may occur in one potato tuber; however, one caterpillar is enough to spoil and destroy. Also fungi and mites develop inside the galleries, causing the decomposition of the tuber and the release of an unpleasant smell.
- Damage can also be important on the tomato, the moth boring into the stems, leaves and the green fruit (*) .

[R]Common Names
DE: Kartoffelmotte ES: Polilla de la patata FR: Teigne de la pomme de terre IT: Tignola della patata. PT: Traša da batata GB: Potato tuberworm, Potato split-worm, Potato moth

[R] Images

  1. Phthorimaea operculella (Zeller) (Coutin R. / OPIE)
    Larvae and damage on tubercle of potato
  2. Phthorimaea operculella (Zeller) (BASF)
    Damage on tomato
  3. Phthorimaea operculella (Zeller) Attacked potato cut in half (Photo F. Picard in Balachowsky & Mesnil)
  4. Phthorimaea operculella (Zeller) Moth (Drawing INRA in Bonnemaison)

To read this page in French

HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.

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