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.
Crops > Trees, palms & pandanus > Trees > Cypress, dieback, St Lucia
July 2005. A request from St Lucia to help identify the cause of a disorder (top row) which was first noticed 2 weeks’ ago in Cyprus lucitanica. This forest tree is planted and sold as Christmas trees in St. Lucia. The browning appears on the stems and leaves and appears to be moving from the bottom of the tree upwards. A few years’ ago some thrips caused similar symptoms, but they could not be found this time. The area planted is 3 acres and about 2 acres show symptoms. The trees are approximately 4 feet tall and are 2 years’ old. NPK is applied to them twice per year and there is routine weed maintenance and pruning if necessary.
Members could not be certain as to the cause, but there were suggestions. In Hawaii Diploptera punctata (Cypress cockroach, beetle roach) causes similar symptoms in Cupressus and other trees. Look for biting on stems, sappy areas, and girdling of branches. Below is a link to a couple of images:
Ethiopia sent pictures (bottom row) of a damage caused by the Cypress aphid, Cinara cupressivora Watson & Voegtlin on Tuja, Cupressus spp. It is very destructive and very hard to control unless biological control agents are involved.