Distribution patterns of coconut mite, Aceria guerreronis , and its predator Neoseiulus aff. paspalivorus in coconut palms (original) (raw)
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Experimental and Applied Acarology, 2012
Densities of coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) and its predatory mite, Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) were monitored on coconut fruits in two coconut mite infested areas, Kalpitiya and Madurankuliya, in Sri Lanka, over a period of 3 years and were compared with local rainfall records. Significant differences in A. guerreronis densities were observed among years and months of the year. Rainfall (amount and frequency, i.e. the total number of days with rainfall of [5 mm) was not significantly correlated with the variation of A. guerreronis densities. But the drought length (i.e. the number of days without rainfall of [5 mm) significantly influenced A. guerreronis densities. Generally, peak densities of A. guerreronis were observed during February-March and June-September in both areas. The differences in the N. baraki densities were significantly different between the two areas and among the 3 years but not among months of the year. Although the amount of rainfall was not significantly correlated with the population densities of N. baraki, frequency of rainfall showed a negative significant correlation and drought length showed a positive significant correlation with the population densities. The results of this experiment indicated that the application of control methods for A. guerreronis may be more advantageous if they are carried out at the onset and during the dry seasons.
Biological Control, 2010
In this paper, we report the first evidence for the suppression of coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae) populations by augmenting the natural population of the predatory mite, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) by an inundative release with laboratory-bred N. baraki. On each of five coconut mite infested palms in two plantations in the same agro-climatic zone of Sri Lanka, 10,000 laboratory-bred N. baraki was released once and the numbers of both N. baraki and coconut mite were assessed over a period of 6 months. Irrespective of the plantation, release of N. baraki resulted in a significant increase in its population on released palms during the post-release period of 6 months with a mean number of 8.99 ± 1.03 per fruit compared to 6.19 ± 0.80 per fruit on unreleased palms. A single release of N. baraki showed a highly significant positive impact on the coconut mite population in the released palms in both plantations. The mean numbers of coconut mites per fruit were 1264.77 ± 139.07 and 1815 ± 46 in the released and unreleased palms, respectively, during the sampling period.
Experimental and Applied Acarology, 2008
A method was developed for the rearing of coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), and its predatory mite Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) on embryo culture seedlings of coconut (Cocos nucifera) in the laboratory. Seedlings in the ages of Neoseiulus baraki was reared on embryo culture seedlings of the three age groups infested with coconut mites, by introduction of five female deutonymphs and one male, three weeks after introducing coconut mites. Predator numbers progressed significantly over time, but the size of seedlings did not significantly influence the numbers. On all groups of seedlings, the mean number of N. baraki increased up to two weeks after introduction on to seedlings and then declined. Many coconut mites were successfully reared in the laboratory for a longer period by this method and it could also be used as an alternative method to rear N. baraki. Development of this method may contribute to the progress of studies on the biology and ecology of coconut mite and its interactions with natural enemies.
Biological Control, 2010
The coconut mite Aceria guerreronis Keifer resides beneath the perianth of coconut fruits where it feeds on the tender meristematic tissue. A. guerreronis is one of the most important coconut pests but knowledge of its population dynamics is scant. We quantified seasonal and fruit age-related population fluctuations of A. guerreronis and its predator Neoseiulus paspalivorus DeLeon in Benin. N. paspalivorus was the most common and abundant beneath the bracts compared with other predators, which were very scarce and were largely found outside the bracts. Both percent fruit occupation and abundance of A. guerreronis and N. paspalivorus varied across sampling months as well as among coconut plantations and fruit age classes. Both parameters peaked in the middle of the rainy season and at the end of the dry season. Fruit age at which A. guerreronis and N. paspalivorus started to colonize the fruits was 0.9 and 1.2 months, respectively. The two species reached their peak abundance (1512 A. guerreronis and 2.3 N. paspalivorus per fruit) on 3 months-old fruits. Peak percent fruit occupation by A. guerreronis ($70%) occurred after 4.3 months, which was 0.7monthsearlierthanthatbyN.paspalivorus(0.7 months earlier than that by N. paspalivorus (0.7monthsearlierthanthatbyN.paspalivorus(22%). Difficulties encountered by the predators in accessing the area beneath the perianth on the very young fruits allowed A. guerreronis a head-start in population build-up leading to strongly diverging population curves as a function of fruit age (higher population increase compared to N. paspalivorus). Protecting the very young fruits from A. guerreronis colonization should be a key issue for developing successful control strategies of this pest.
The Coconut Mite, Aceria Guerreronis Keifer (Acari: Eriophydae) – A Plague in Kerala
2015
The coconut mite, Aceria guerreronis Keifer, has emerged as a sporadic pest of the coconut plantations in India inducing serious damage. Coconut provides one third of the agricultural income in Kerala and a major population are dependent on this cash crop directly or indirectly through coconut-based industries like coir, copra, oil, honey, furniture, handicrafts, beverages, bakery products and so on. The economic instability of the coconut farming community and the people employed in coconut-based industries rank the highest order. A critical assessment of the various problems created by the mite A. guerreronis in the agricultural economy of Kerala is presented from a historical point in order to supplement data on crop loss through nut malformation, nut fall, loss in fibre and copra. Future strategies in terms of management practices for an early control of the mite are outlined, and suggestions to alleviate mite damage are presented.
BioControl, 2016
Predators face the challenge of accessing prey that live in sheltered habitats. The coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae) lives hidden beneath the perianth, which is appressed to the coconut fruit surface, where they feed on the meristematic tissue. Its natural enemy, the predatory mite Neoseiulus paspalivorus De Leon (Acari: Phytoseiidae), is larger than this pest and is believed to gain access to the refuge only after its opening has increased with coconut fruit age. In the field, experimentally enlarging the perianth-rim-fruit distance beyond the size of the predators resulted in earlier predator occurrence beneath the perianth and lower numbers of coconut mites. On non-manipulated coconut fruits, the predators gained access to the prey weeks later than on manipulated ones, resulting in higher pest densities of coconut mites. Successful biological control thus critically hinges on the size of the predator relative to the opening of the prey refuge.
Neotropical Entomology, 2008
Ocorrência de Aceria guerreronis Keifer (Acari: Eriophyidae) e Predadores Associados em Frutos de Coqueiro no Nordeste do Brasil RESUMO -Aceria guerreronis Keifer pode causar danos severos em coqueiro em vários países ao redor do mundo. Raros estudos têm sido conduzidos para determinar os ácaros predadores associados com A. guerreronis no Brasil. O objetivo deste estudo foi avaliar a prevalência de A. guerreronis e dos predadores associados nas brácteas e na superfície dos frutos abaixo delas, durante 12 meses, em frutos de coqueiro adulto ao longo da costa de Alagoas, Paraíba e Pernambuco, no Nordeste do Brasil. Ácaros de 10 famílias foram encontrados, contudo a espécie mais abundante foi A. guerreronis, correspondendo a 99,5% dos ácaros coletados. Dentre as espécies predadoras prevaleceram os ácaros Phytoseiidae Neoseiulus baraki (Athias-Henriot) e Neoseiulus paspalivorus (De Leon). Estes são achatados e possuem pernas curtas, características que lhes permitem invadir o habitat ocupado por A. guerreronis. Outros predadores foram encontrados, mas em número bem menor, provavelmente pela difi culdade que têm em penetrar nas áreas comumente habitadas por A. guerreronis. Contudo, essas espécies têm potencial de predação sobre o ácaro quando este sai de seu habitat preferido para se dispersar. Não se observaram correlações signifi cativas entre os níveis de fatores abióticos e os níveis populacionais de A. guerreronis ou dos fi toseídeos associados a essa espécie. Isso provavelmente se deu devido aos efeitos simultâneo e confl itante daqueles fatores sobre os ácaros no campo, ou a diferenças signifi cativas entre os fatores climáticos medidos no ambiente e aqueles prevalentes no habitat ocupado por A. guerreronis. PALAVRAS-CHAVE: Ácaro do coqueiro, ácaro predador, controle biológico, Phytoseiidae
International Journal of Biosciences (IJB), 2013
In the experiment, coconut was collected randomly from Khulna, Satkhira and Bagherhat districts of Bangladesh and categorized into five grades based upon infestation pattern of coconut mite on coconut. The experimental treatments of factorial experiment consisted of three locations (L1= Khulna, L2 = Bagherhat and L3 = Satkhira); two varieties (V1= Green and V2= Brown) and five grades on the basis of mite infestation which are G0 = nuts with no mite damage, G1 = nuts with 1-29% surface area damage, G2 = nuts with 30-59% surface area damage and less than 20% reduction in size, G3 = nuts with 60-80% surface area damage, 20-30% reduction in size and G4 = nuts with over 80% surface area damage with 30% reduction and often greatly deformed. From the study it was found that most of the cases highest values were recorded from G0 and the lowest values were recorded from G4. It was found that the dry weight of copra was significantly varied among the different grades. The highest dry weight (164.33g) was recorded from G0 and the lowest (386.94g) from G4. Among the location, the fruits collected from Khulna and Satkhira gave highest values and the lowest value was recorded from the fruits of Bagherhat district. From the experiment it was found that water loss was observed about 0, 5.5, 34.19, 50 and 62.59% in damage categories of G0, G1, G2, G3 and G4, respectively. For the copra yield considerable loss was occurred that ware 0, 13.22, 24.90, 38.00 and 52.72% in damage categories G0, G1, G2, G3 and G4, respectively. Observed coconut shell losses were 0, 7.28, 15.32, 24.42, and 37.17% corresponding to damage categories G0, G1, G2, G3 and G4, respectively. Due to mite infestation about 37.17% coconut shell loss, 62.59% water loss and 52.72% copra yield loss was occurred when nuts with over 80% surface area damaged with 30% reduction of size.