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Autographa gamma (L.)
Phytometra gamma, Plusia gamma

Insecta, Lepidoptera, Noctuidae .

Silver y moth, Common silver y moth

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

- Adult: 40 to 45 mm wingspan. Brownish-yellow fore wings with, at their centre, a white spot resembling the shape of the Greek letter gamma. The hind wings are light brown, smoked at their periphery (*) .
- Larva: 40 to 45 mm, light green with 6 longitudinal whitish lines (*) . Small and yellowish head, narrow anterior third of the body. Provided with 2 pairs of abdominal prolegs and one pair of anal prolegs, it moves about as a span-worm (*) .
- Eggs: greyish white, flattened, they are deposited in bunches or singly on the underside of the leaves, generally, of wild plants or of certain cultivated plants.

- Host plants: the larvae first attack the leaves of certain wild plants, then, in cultivated plots, the leaves of red beet, potatoes, cereals, flax, vegetables and even nursery plants.
- Adult: the moths, generally nocturnal, fly very rapidly, either alone or in small groups, sometimes in swarms which can be composed of millions of individuals travelling over hundreds of kilometers.
- Larva: the caterpillar is especially active during the night: it nibbles the lamina of leaves and cuts the leaf-stalks (petioles). During the day, it remains pressed against the underside of the leaves. Larval development lasts about a month.
- Pupa: the larva pupates in the folds of the leaves of the host plant (*) and the adults emerge 10 to 15 days later.

[R]Life Cycle
- The importance of the migrations leads to a geographical distribution of the species which differs considerably from season to season, so there is no distinct development cycle in any given place. The common silver y moth is common in North Africa and in the Mediterranean basin during winter; in summer, it occurs as far north as Scotland and Finland.
- The adults fly in the Paris region from the end of May to the beginning of June. A second flight takes place generally at the end of July.

In years of swarming, colonies of thousands of individuals invade cultivated fields (red beet, potato, etc.). The older caterpillars are particularly voracious (*) . Such invasions enable the development of numerous natural enemies of the caterpillar, particularly certain viral diseases whose effect is such that the second generation is almost non-existant.

[R]Common Names
DE: Gammaeule ES: Noctuido gamma FR: Noctuelle gamma IT: Nottua gamma PT: Nóctua gama GB: Silvery moth, Common silver y moth

[R] Images

  1. Autographa gamma (L.) (BASF)
    Chenille The number of abdominal prolegs is reduced.
  2. Autographa gamma (L.) (BASF)
    Attack on beet
  3. Autographa gamma (L.) Moth Landed on a Chrysanthemum.
  4. Autographa gamma (L.) Moth Feeding on Sedum.
  5. Autographa gamma (L.) Cocoon The silk, always very flimsy, allows the pupa to be seen.
  6. Autographa gamma (L.) Larva (Rasplus J.-Y. / INRA Versailles)

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