Impact of weather parameters on Raoiella indica Hirst. (Acari: Tenuipalpidae) on coconut (Cocos nucifera L.)

Abstract

The red palm mite, Raoiella indica is a serious pest of several species of Arecaeae including Areca catechu, Cocos nucifera and Phoenix dactylifera as well as Musaceae (Musa spp.). It was first reported in the Caribbean islands in 2004 and has since spread throughout the region causing widespread damage to coconut in particular. The current study was designed to determine the relationship between several weather parameters (viz. minimum and maximum temperature, rainfall and relative humidity) and population levels of different life stages of R. indica. A series of stage-specific life tables were also constructed using the collected data. Multiple regression and correlation analyses indicated that collectively, all four weather parameters significantly influenced each life stage of R. indica. Sex ratio was significantly influenced by all weather parameters examined except rainfall. Graphical key factor analysis and regression of sub-mortalities (k) against total mortality (K) of the life tables generated indicated that mortality (k2) in the nymphal stages (protonymph and deutonymph) contributed most to overall mortality (the key factor).