Crops
Defoliator pests
Some pests are likely to gnaw, devour the leaves of salads. Their actions frequently result in the partial or total disappearance of more or less large and regular portions of the limbus.
The slugs particularly appreciate the salad leaves, they are grown under cover or in open fields and this whatever their stage of development. They sometimes cause significant losses. We observe :
- the more or less deep consumption of the leaf blade (figure 1) making the salads unmarketable.
When searching carefully, it is not uncommon to find the guilty slugs (Figures 2 to 4). Several species of slugs can be found in market gardening:
- Deroceras reticulatum , the gray slug or loach. It measures between 3 and 5 cm and has a grayish to brown color;
- Deroceras laeve , a smaller and more mobile slug, the length of which is limited to 2.5 cm;
- Arion hortensis , the black garden slug. 2 to 4 cm long, it is more difficult to spot because it readily hides in the ground several centimeters deep.
These slugs breed all year round, except during very cold and / or very dry periods.
On the other pests , including several adults, caterpillars and larvae of insects attack the leaves salads. They can be rife very early, in the nursery or in the days following planting or on adult salads. In fact, depending on the insects and the stage of plant development, the damage can be different:
- wilting of the seedlings, disappearance of the latter,
- root consumption,
- sectioning of the collar,
- consumption of the blade leading to the appearance of more or less numerous and rounded holes (figure 5).
As with slugs, the culprit (s) are usually not far away (Figure 6). By looking closely at the affected plant (s) and their environment, we can find the pest (s) involved.
Main insects prevalent in nurseries, after planting and during cultivation, which may be the cause of leaf perforations in France:
| Organs attacked and nature of the damage |
Last name | Description of the pest |
| Gnawed collar and leaves near the grazed ground |
Bourletiella hortensis
(Garden Collembola)
|
Black to dark green adults, 1.5 mm long. Big head with long antennae. Prominent black eyes circled in yellow |
| Gnawed collar and cut leaves |
Agrotis spp. ...
(cutworms, soil-dwelling moths)
|
Caterpillars 3.5 cm long, fleshy, variable in color, greyish to greenish, topped dark spots or bands |
| Cut leaves |
Autographa gamma
(Noctuelle gamma)
|
Caterpillars 3.5-4.5 cm long, green to blackish green, with 3 pairs abdominal prolegs |