Arugula is a salad plant that belongs to the cruciferous family. As such, it represents a host plant for typical pests on Brassicaceae. But only two species can be really dangerous for the plant.
Arugula is only attacked by a few pests
flea beetles
Arugula is a favorite food for the canola flea beetle (Psylliodes chrysocephalus) because the lettuce plant has a soft and delicate leaf tissue. The affected leaves no longer look appetizing due to the feeding activities of the blue-black to dark green colored beetles. If young seedlings are infested, they cannot withstand the pest pressure and die.
damage
The females lay their eggs on the substrate at the base of the plants in spring. Within the next ten days, white larvae develop, which burrow into the soil and feed on the thread roots for three weeks. The rocket usually survives this feeding activity without any problems.
Pupation takes place in a soil cocoon. Adult beetles hatch from June to August and feed on the leaf mass of young plants. Window eating is a typical symptom of flea beetles. As the insects scrape the leaf surface, leaf membranes are left behind. They dry out, take on a pale brown color and tear open. The windows are no larger than four millimeters.
prevent infestation
Start sowing rockets early so that the plants are strong enough for the main beetle flight season. Crop protection nets prevent the pests from reaching the plant base to lay their eggs. Mixed crops with spinach and onion plants reduce pest pressure.
You can do this:
- Keep the substrate moist, as insect pests prefer dry conditions
- Reveal puppets by regular chopping
- Pulling weeds to deprive food bases
- Manure made from tansy and wormwood serve as a repellent
- Rock flour (€14.13) and algae lime prevent egg laying
Cabbage Whites
These moths are a prime example of natural adaptations to plant defense strategies. Like many cruciferous plants, arugula produces secondary plant substances, which are converted into mustard oils when the plant tissue is damaged by caterpillars. They cause the pungent taste and are toxic to insects. Cabbage whites have long co-evolved with cabbage plants and have evolved an intestinal protein that reduces the toxicity of mustard oils. Their larvae can safely feed on rocket leaves until they pupate.
Typical species
The Lesser Cabbage White leaves single eggs on the underside of leaves, which are pale yellow in color and ribbed lengthwise. The first pale yellow and later light green roaches have a light yellow back line and dots of the same color on the segments. Green colored larvae with yellow stripes and black spots hatch from the bright yellow egg packets of the cabbage white.
Effective control methods
Trichogramma parasitic wasps (€18.99) parasitize the butterflies' eggs, preventing further development. The species Cotesia glomerata and Cotesia rubecula belong to the group of braconids that inject their eggs into the caterpillars. These die after the beneficial insects have fully developed and left the body.