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.
A member wrote that he had seen similar symptoms on coconuts in Tonga in the 80s and 90s, when he worked there on coconut pests. He said that because the damage is not common and does not seem to affect the coconut meat or water there has been no research as to its cause.
A moderator said that he suspected that C. noahebridensis is widespread in the Pacific (possible represented by the image above in Port Vila, Vanuatu).
An email on C. novahedidensis was sent from the Coconut list.
It is present only in Darwin, Northern Territory, Australia. The New Hebrides coconut mite is recorded from Vanuatu, Costa Rica, Malaysia, Philippines and East Timor, but not previously in Australia.
The mite lives beneath the perianth of fruits where it feeds on meristematic tissue leading to surface scars, reduced fruit growth causing premature fruit fall. In East Timor, where it may have caused damage since the early 1950s, yield losses are estimated to be 2-3% of copra production.
The Northern Territory reported that the mite (Colomerus novahebridensis Kiefer) was detected in the Darwin Botanic Gardens on 19 May 2008 by an international mite expert. It was initially misdiagnosed as the coconut rust mite Aceria guerreronis Kiefer. Mites and their damage were subsequently detected on several established Malayan yellow dwarf coconut trees and four other locations within a 5 to 6 km radius of the first site. It is very likely that the mites have also spread elsewhere within the Darwin area. The planting of coconuts in the Northern Territory is generally for aesthetic reasons and there is little or no production value except for the nursery trade (estimated at in excess of $40,000 annually) and for the collection of nuts for drinking by the tourist trade.
Hugh Harries (Coconut list) sen the following articles and notes C. novahedridensis:
There is a photograph in a 1949 publication that shows coconut fruit scarring in Colombia that looks very much like mite damage (see attached mite damage.jpg)
Martyn, E.B. (1949) Notes on a visit to Colombia: some observations on the diseases of coconuts and bananas in the Province of Magdelana. Tropical Agriculture (Trinidad) 26, 48-50.
Martyn did not mention mites, but said that he had seen similar damage in British Guiana (Guyana) in 1938 and had read about similar symptoms described as “Ring Disease of Immature Fruits” in New Guinea in 1937:
Dwyer, R.E.P. (1937) The diseases of coconuts in New Guinea. New G. Agric. Gaz. 3 (1) 28-93.
In 1977, concerned by the increasing seriousness of coconut mite damage in West Africa, the Caribbean and South America, the Ministry of Overseas Development (ODM) in London and the Institut de Recherches pour les Huiles et Olagineux (IRHO) in Paris, jointly funded a preliminary programme of research into biological control of Eriophyes guerreronis (the generic nameAceria had been dropped), by making a survey of the Pacific and Indian Ocean areas, where the problem did not exist on the same scale.
In July 1978 the first project report drew attention to the presence of Colomerus novahebridensisfrom the Philippines to the New Hebrides (Vanuatu) and recommended that laboratory-reared mites could be used to test whether this mite may displace E.guerreronis. (see attached mite survey.pdf)
I don’t know if that test was ever made but the change in generic name, back to Aceria, may mean that the work reported on Eriophyes guerreroniswill be overlooked and forgotten! The coconut mite, Aceriaguerreronis
The mite was first reported in Guerrero, Mexico and now found in most of the coconut producing areas in South Asia, Central and South Africa, including the Gulf region. In Dhofar, it was reported in the late 1980s. “Agriculture scientists from all the affected countries are sharing information with each other to handle the issue in a positive manner,” said Anwar.
OBSERVER SPOTLIGHT — By Kaushalendra Singh — SALALAH — The Agriculture Research Station Salalah has decided to put concerted and integrated efforts to tackle the issue of coconut mite. After making good progress under a five-year programme, the Research Station has extended the programme for one more year, as an Integrated Pest Management (IPM) plan is in place with emphasis on biological control using predators etc. The mite problem is being tackled strategically by understanding the coconut mites’ ecology, distribution and business as also by developing good plant protection and production practices.
Among other methods being adopted by the researchers is plantation of 11 new varieties of coconut. These new varieties were brought from Cote de’Ivoire (South Africa) and planted during the last Khareef season. With this the agriculture scientists are hoping good quality coconuts in terms of quality and quantity in the years to come, as these varieties of coconut are mite resistant. In the meantime, the agriculture research centre has successfully tackled the mite issue by adopting scientific measures and raising awareness among the farmers.
According to Anwar Ahmed Bait Fadhil, “We did intensive research after the coconut mite attack and found the varieties from Cote de’Ivoire mite resistant and comparatively better in farm output. The success rate of these plants is also encouraging,” he said. “We are trying to convince the farmers about new methods through presentations, direct contact, workshops and seminars. We take part in programmes, activities and awareness drives for farmers. The experts from the ministry explain ways to improve farm productivity, proper use of fertlisers and pesticides as also tackling the problems of coconut mite and papaya mealybug,” said Bait Fadhil.
Anwar put emphasis on the fact that the mite attack on coconut was limited only to the fruit bark and not at all on the pulp and its milk. “It is a kind of cosmetic issue with the coconut, as the fruit remains tasty, sweet and healthy despite the mite attack.” The coconut mite or Aceria guerreronis Keifer attacks young fruits of the coconut palm, to which it is almost exclusively confined. The mites are small but they often build up extremely large and dense populations. They use the bark as their food which causes scarring and distortion of the fruits and in some cases cause premature fruit drop. The mite was first reported in Gurrero, Mexico and now found in most of the coconut producing areas in South Asia, Central and South Africa, including the Gulf region. In Dhofar it was reported in the late 1980s. “Agriculture scientists from all the affected countries are sharing information with each other to handle the issue in a positive manner,” said Anwar.