A network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests.
PestNet is a network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests. It started in 1999. Anyone with an interest in plant protection is welcome to join. PestNet is free and is moderated, ensuring that messages are confined to plant protection.
September 2009. From south Vietnam, Longan shoots severely deformed, and thought to be caused by herbicide application.
Members did not agree that it was herbicide damage. It was thought to be similar to that caused by Yellow tea thrips, Scirtothrips dorsalis Hood. This pest is present in the whole of South East Asia, Africa, Eastern Australia and USA (California and Florida), and in New Caledonia. Damage from the thrips in New Caledonia is mainly on Litchi sinensis, and it is severe. The affected trees look as if they have a virus. It seems that the thrips attacks when plants are stressed. Summer oil sprays are normally effective against it.
The symptoms also resemble those caused by Eriophyes litchii (Keifer) an Eriophyidae mite, Lichi erinose. To check, take the very small leaves at the growing point – ones that show symptoms – and place them in a small clear screw-top bottle with 80% ethanol. Shake, and if there are any mites are present they will be seen at the bottom of the bottle in the ethanol mix. Eronose mites are generally difficult to find on leaves with a hand lens.