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.
In late September, there was an outbreak of flea beetles on eggplants in a backyard garden in Sigatoka, Fiji. The infestation seems to have started on the crops next to a compost heap (mixture of collected dried seaweed and poultry manure). Perhaps pupae were already in the poultry manure. The flea beetles did not spread evenly to the planted area, but rather clustered on just about a third of the crop. Plants were not treated in order to observe the behaviour of these beetle, and their natural enemies.
According to the Pacific Pests and Pathogens Fact Sheet (Eggplant flea beetle – 247), this particular or similar flea beetle was recorded in Fiji and Tonga as Psylliodes brettinghami. Any suggestions on control.
Pestnet factsheet #247 is a very good reference. Yes, there probably is a source of infection, but it is probably older Solanum plants? Get rid of those sources of infection, although it is probably too late now? Do all you can to protect the small plants until they are big and healthy, and then big healthy plants should be able to tolerate some levels of infestation. Unfortunately, I do not know of any effective natural enemies of flea beetle on any crops anywhere in the SW Pacific or SE Asia. However, there are alternatives to the last option in the fact sheet (spraying synthetic pyrethroids (SPs) = kill all the natural enemies).
You have the plant-based insecticides (as in the factsheet) and then there are systemic insecticides. But they have their IPM incompatible issues too, but not as toxic to natural enemies as SPs. Eggplant is a long-growing crop so that you might be able to apply a systemic insecticide early, taking into consideration the long with-holding periods (WHPs) for most systemic products. Check the label carefully if you decide to use a systemic insecticide (WHP’s, toxicity to bees, etc.).