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.
November 2017. Two coconut palms in a backyard on the northern side of Fiji (dry zone) are affected with what looks like a powdery sticky powder. Could this be mites. And if so what to do about them? The bottom photo shows normal coconuts for comparison. It is difficult to tell from the photograph, but is it showing the nuts encrusted with armoured scales? The obvious armoured scale to expect would be Aspidiotus destructor, which has been present in Fiji for a long time and is normally controlled by predators and parasitoids. Possibly, something has reduced natural enemy populations, allowing the scales to proliferate? Bear in mind that the parasitoids are highly susceptible to pesticides, so if there is heavy pesticide use this may have caused a scale outbreak. If that is the case, stopping pesticide use is the best way to allow the natural enemies to re-colonise the area. If it is absolutely necessary to control the scales quickly, horticultural oils are less toxic to the natural enemies than are other types of pesticide.
An alternative explanation could be that Aspidiotus rigidus (currently damaging coconuts in the Philippines) could have got introduced to Fiji accidentally. If that is the case, the problem could become serious and widespread.
Others were concerned to hear that the coconut false scale (Aspidiotus rigidus), which is not yet in the Pacific islands, could be a possibility. BUT there are other scales that might be the cause. Other than Aspidiotus destructor, Hemiberlesia palmaeor Hemiberlesia lataniae are possibilities. Authoritative identification must be done based on slide mounted adult females.