Insect Pests of Trees: Identification & Control
Insect Pests of Trees
Lepidoptera
Thaumetopoea pityocampa (Pine processionary)
Type: Lepidoptera
Damage: Defoliator
Affected Area: Pine shoots
Description: Early flight occurs during mild days in March-April. Adults lay eggs, caterpillars appear in May-June, and pupation occurs in July. Larvae have two stages.
Dioryctria mendacella
Type: Lepidoptera
Damage: Borer
Affected Area: Pine cones
Description: Two generations per year. Larvae develop in spring and fall. Eggs are laid, and larvae drop to the soil to pupate. Pupation lasts one month in summer and 2-3 months in winter. Red excrement.
Tortrix viridana (Green oak tortrix)
Type: Lepidoptera
Damage: Defoliator
Description: Females lay around 60 eggs, mostly on branches. Caterpillars have two stages: gray when newly hatched and brownish in the second stage. Pupae are 9-11 mm long and dark brown. Adults appear in May-June and live for about a week. Eggs hatch in March-April. Larvae damage tender spring shoots.
Lymantria dispar (Gypsy moth)
Type: Lepidoptera
Damage: Defoliator
Affected Area: Primarily oak, but attacks many species
Description: Females are 45-65mm long with yellowish bodies. They lay 200-500 eggs. Females are flightless, while males can fly. Eggs last for nine months, hatching in April. Caterpillars live for two months, and pupation lasts three weeks. Polyphagous species.
Malacosoma neustria (Lackey moth)
Type: Lepidoptera
Damage: Defoliator
Affected Area: Tender leaves of various species
Description: Females are 35-40mm long and lay 70-130 eggs around thin branches. Eggs overwinter. Adults emerge from May to June. Larvae develop in late April-May. Pupation occurs in May-June, and adults emerge after one to three weeks.
Catocala nupta and C. nymphagoga
Type: Lepidoptera
Damage: Defoliator
Affected Area: Tender leaves
Description: Eggs are laid on the ground or in bark crevices. Each female lays about 200 eggs. Larvae hatch in April-May and remain until late May-early June. Pupation lasts 18-20 days, followed by adult emergence.
Euproctis chrysorrhoea (Brown-tail moth)
Type: Lepidoptera
Damage: Defoliator
Affected Area: Buds, leaves, and flowers of many species
Description: Polyphagous species. Lays 150-300 eggs. Adults emerge in late June-early August. Larvae develop in 2-3 weeks, reaching maximum development in August-September. Pupation lasts two weeks.
Coleoptera
Pissodes validirostris (Pine weevil)
Type: Coleoptera
Damage: Borer
Affected Area: Pine cones
Description: Overwinters as adults. Females lay eggs in April-May. Larvae develop inside pine cones. Adults emerge in September-October.
Cerambyx cerdo (Great Capricorn beetle)
Type: Coleoptera
Damage: Borer
Affected Area: Oak
Description: Xylophagous insect. Adults emerge in July-September. Larvae hatch a few days after eggs are laid and feed under the bark, creating irregular galleries. Larval stage lasts 2-3 years.
Coroebus undatus
Type: Coleoptera
Damage: Borer
Affected Area: Cork oak
Description: Eggs are laid in cork cracks. Adults emerge in May-June and live for about 20 days. Larvae hatch in 10-20 days and live for two years, creating galleries. Pupation occurs in April-May.
Coroebus florentinus
Type of insect: Coleoptera Damage: Punch Area affected: Quercus Description: eggs isolated at the end of the branch, perfect insect is born from June to July, eggs in holes cortex, gallery interior descending branch, branch and cut ring wise. Slash and burn of branches attacked.