MySheen

Control of rhododendron crown net bug

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, Host and damage characteristics: damage to rhododendron and horse drunken flowers. The adult and nymph sucked leaf sap and excreted feces, resulting in needle-like white spots on the front of the leaves to all-white green, yellow on the back of the leaves, hindered plant photosynthesis, slow growth and early defoliation. Morphology and habits: the adult is small, flat, dark brown, nearly 4 mm long, and the membrane of the forewing is covered with reticulate patterns. The anterior chest dorsal plate extends forward to cover the head, and there is also a reticular pattern on it. In Guangzhou, about 10 generations occur every year, overwintering with adults and nymphs.

Host and damage characteristics: damage to rhododendron and horse drunken flowers. The adult and nymph sucked leaf sap and excreted feces, resulting in needle-like white spots on the front of the leaves to all-white green, yellow on the back of the leaves, hindered plant photosynthesis, slow growth and early defoliation.

Morphology and habits: the adult is small, flat, dark brown, nearly 4 mm long, and the membrane of the forewing is covered with reticulate patterns. The anterior chest dorsal plate extends forward to cover the head, and there is also a reticular pattern on it. In Guangzhou, about 10 generations occur every year, overwintering with adults and nymphs. Nymphs are clustered. The main natural enemies are lacewings, followed by spiders and ants.

Prevention and treatment methods: ① protects and uses natural enemies and staggers or does not use drugs according to the activity and number of natural enemies. In addition, the application method can be improved. 3% carbofuran granules can be applied into the soil (5 g / pot, 3 cm) or try to choose an internal inhaler, which can be applied with 40% omethoate EC 50 times liquid coating method or 100% 200 times liquid irrigation method. ② sprays nymphs in time, focusing on overwintering adults and first-generation nymphs on trees, spraying 45% dichlorvos, 50% fenitrothion, 50% malathion EC 1000 times, or 40% methamol EC 2400-4000 times, or 20% Sima EC 1500 times.

 
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