Evaluation of population dynamics and nutrients on infestation of coconut mite, Aceria guerreronis Keifer

Abstract

The coconut eriophyid mite was reported to cause damage in coconut in the southern region of
Bangladesh. Study on the population dynamics of coconut mite, Aceria guerreronis K. was conducted
to record their seasonal fluctuation. The mite population on the nut surface ranged were 47.94 to
94.67 mites/25 mm². The highest mite population (94.67/25mm²) was observed in the second
fortnight of May. The mite population on perianth fluctuated from the lowest of 18.11 mites (second
fortnight of July) to the highest of 44.33 (second fortnight of May). The average damaged percentage
of nuts were 86.76 (range 80.40 to 94.69%) throughout the year. Among the different nutrients
applied to the soil as urea 1.3kg + TSP 0.7kg + MP 2kg) + MOP (1.5kg) + MgSO4 (50g) +borax (50g)
+ gypsum (1.0kg) were significantly superior in reducing the mite population (16.89, 73.34%
reduction) with the highest reduction percentage of infestation over untreated control (86.62%). Also
treatment provided more healthy nuts (53.17 nuts/4 bunches), the least percentage of infested
coconut (11.63%) and the highest benefit cost ratio was recorded (2:28) as compared to other
treatments.