Coconut Research Institute, Lunuwila, Sri Lanka.
Exp Appl Acarol. 2012 Apr;56(4):319-25. doi: 10.1007/s10493-012-9519-z. Epub 2012 Feb 11.
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.
在斯里兰卡的两个椰子螨疫区（Kalpitiya 和 Madurankuliya），对椰子果实上的椰子螨和其捕食性螨（粉虱细蜂科）的密度进行了为期 3 年的监测，并与当地的降雨记录进行了比较。结果发现，A. guerreronis 的密度在不同年份和月份之间存在显著差异。降雨量（数量和频率，即有降雨量 >5 毫米的天数）与 A. guerreronis 密度的变化无显著相关性。但是，干旱持续时间（即无降雨量 >5 毫米的天数）显著影响了 A. guerreronis 的密度。一般来说，A. guerreronis 的高峰期出现在这两个地区的 2 月至 3 月和 6 月至 9 月。N. baraki 的密度在这两个地区之间以及在 3 年内存在显著差异，但在年内各月之间没有显著差异。尽管降雨量与 N. baraki 的种群密度没有显著相关性，但降雨频率呈负相关，干旱持续时间与种群密度呈正相关。该实验结果表明，如果在干旱季节开始时和期间实施控制 A. guerreronis 的方法，可能会更有利。
