Elm leaf beetle (Xanthogaleruca luteola)
Are the leaves of your elm trees getting holes like there was a hailstorm? If so, there is an insect that attacks the tree: The elm weevil.
• Description of the insect: coleoptera (beetle). Larvae and adults are responsible for creating damage. Size: 5-7 mm.
• Affected species: Elm.
• Biology: The female lays eggs behind the leaf and after 8 days the larvae are born. In mid-July the adults are born and a 2nd generation begins. In autumn the adults take shelter under the bark.
• We recommend plant endotherapy:
- Apply nutrient and insecticide injections every 15 cm around the perimeter of the tree trunk.
• Recommended products for individuals
- For 15 l rucksacks: contact insecticide and massometric ingestion of 10 cc.
• Products recommended for professionals:
- For higher capacities: Decis Protech contact insecticide of 1l at a dose of 1cc/l.
- Phytosanitary treatments with insecticidal products in the spring. The most recommended active ingredients are pyrethrins (deltamethrin).
- Alternative methods: placing injections with insecticide.
SYMPTOMS AND DAMAGES
- The first symptoms are "holes" in the leaf leading to total defoliation, as if a very heavy hail had fallen and caused the perforations.
- The weakening of the tree favors the presence of borers.