The Coconut Mite, Aceria Guerreronis Keifer (Acari: Eriophydae) – A Plague in Kerala (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.
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.
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, 2003
Distribution patterns and numerical variability of the coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae) and its predator Neoseiulus aff. paspalivorus DeLeon (Phytoseiidae) on the nuts of 3- to 7-month-old bunches of coconut palms were studied at two sites in Sri Lanka. At the two sites, coconut mites were present on 88 and 75% of the nuts but no more than three-quarters of those nuts showed damage symptoms. N. aff. paspalivorus was found more on mature nuts than on immature nuts. Spatial and temporal distribution of coconut mites and predatory mites differed significantly. The mean number of coconut mites per nut increased until 5-month-old bunches and declined thereafter. The densities of predatory mites followed a similar trend but peaked 1 month later. Variability in the numbers of mites among palms and bunches of the same age was great, but was relatively low on 6-month-old bunches. The results indicate that assessment of infestation levels by damage symptoms alone is not reliable. Sampling of coconut and/or predatory mite numbers could be improved by using several nuts of 6-month-old bunches. The effect of predatory mites on coconut mites over time suggests that N. aff. paspalivorus could be a prospective biological control agent of A. guerreronis.
Observations were recorded on traits associated with mite infestation related at two stages of button on six different coconut cultivars over three years. Highly significant correlation was found between mite damage score with color or weight of tepal. Step-wise multiple regression of the data analysis showed color of inner tepal as major trait associated with infestation by eriophyid mite. Other traits are ratio of tepal weight to tepal area, per cent of buttons with pink discoloration or with resin, tepals of regular aestivation and gap between fruit and tepal. Digital phenotype data of 83 image files were used to calculate color signature and correlated the same to mite damage score over three years. Red spectral values were found to vary from 14 to 251, green values to 12 to 237 and blue to vary from 5 to 183. Spectral values red max, green max, 3* Red + Green max had high significant negative correlation (>-0.4) with mite damage. Color and firmness of fruits and tepals of three coconut varieties were further analyzed where, fruits and tepals of COD variety showed high red/green (a* value of Hunterlab) >12. Firmness of 3 month old tepal and fruit of Benualim (BGRT) tall variety was (penetrometer reading >38) higher than other varieties.
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.
Effect of Botanicals on Infestation Intensity of Aceria Guererronis Keifer in Coconut
Journal of Plant Protection Research, 2010
The withdrawal of chemical pesticides opens up a new perspective to control pests through botanical extracts. The essential oils derived from various medicinal and aromatic plants proved to have antifungal, antibacterial and insecticidal properties. The present study is directed towards management of a dreaded pest of coconut i.e. eriophyid mite through exploitation of those properties of the plants. The efficacy of a botanical biocide formulated by using seven different aromatic and medicinal herbs against the infestation intensity of eriophyid mite was tested in the experiment at five different coconut farms in different coconut growing states of India.
The research trial on 'Influence of weather parameters on incidence of coconut eriophyid mite, Aceria guerreronis (Keifer) (Acarina : Eriophyidae)' was conducted during 2014-2016 at Asond block, Central Experimental Station, Wakawali, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, such as minimum temperature, maximum temperature, morning relative humidity, evening relative humidity, sunshine hours and rainfall. The results revealed that, among the various meteorological parameters the maximum temperature and sunshine hours found to be significantly positively correlated with per cent infestation and showed significant correlation values of 0.504 and 0.404, respectively. This indicated that as temperature increased percent eriophyid mite infestation get increased. Similarly as sunshine hours increases, the percent eriophyid mite infestation also increases.
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