Crops
Selepa docilis (Butler)
(hairy caterpillar)
General
- Insect belonging to the order of Lepidoptera, and to the family of Noctuidae.
- The species is mainly observed on eggplant
- Sensitive botanical family (s)
| Eggplant |
- Affected production areas :
| Mayotte |
- Organs attacked
| Leaves |
Symptoms, damage
- Symptoms :
- The caterpillars eat away at the leaves and leave only the main veins.
- Signs : Presence of larvae grouped together on the leaves, and of butterflies on the plants and in the culture.
- Possible confusion :
Biology
- Development cycle : includes 4 development phases: egg, larva or caterpillar, pupa or chrysalis, and butterfly.
- The eggs are often deposited singly on the edges of the leaves.
- They then hatch and give birth to caterpillars with powerful mandibles that allow them to consume the leaves. Caterpillars have long bristles on their body. They moult several times, before pupation or chrysalization.
- The pupae are isolated in a conical shaped cocoon.
- The adults are butterflies with 2 pairs of wings and whose wingspan varies from 18 to 20 mm in wingspan. They are characterized by a light brown color.
- Dispersal : Caterpillars are mobile and move easily from leaf to leaf like adults, who do so more easily
Protection
- Weed the crop and its surroundings.
- Produce the seedlings in an nursery insect-proof .
- Check the sanitary quality of the plants before and during their introduction into the crop or shelter.
- Install canvases insect-proof in nurseries and at shelter openings when weather conditions allow.
- Install pheromone traps outside the shelter. (1)
- Favor natural enemies in field crops or under open shelters (2).
- Use biopesticides (3).
- Reasoning about chemical protection.
(1) Selective trapping with pheromones can be used to limit the parasitic pressure of this insect. The monitoring of the traps will make it possible to follow the evolution of the population of adult moths and therefore to more precisely position the Bt-based treatments.
(2) Certain parasitoid auxiliaries (Hymenoptera and Tachineus fly) allow the larvae of to be controlled naturally Sodoptera eridania .
(3) The use of a product based on the insecticidal bacterium Bacillus thuringiensis (Bt) makes it possible to kill the young larvae of moths which ingest the product by consuming the cabbage leaves. As the sun inactivates Bt-based formulations and the young caterpillars are especially active at night, applications at the end of the day will be preferred to ensure good treatment efficiency. Irrigation by sprinkling the plot should not be started after the treatment, which would otherwise risk being completely washed out.