A BAIT AND TRAP METHOD FOR SAMPLING SYMPHYLID POPULATIONS IN PINEAPPLE

We developed a standardized method to monitor the symphylids (Hanseniella sp.) populations in pineapple using bait and traps. Two methods for symphylid extraction and enumeration were tested. Two statistical methods, the “variance/mean” ratio and a spatial analysis (Moran and Geary indices) were used to describe the type of spatial distribution of the populations. This bait and trap method allows a good evaluation of the symphylid populations. The ratio between adults and larvae may be used as an indicator of the population growth statute. Data collected on a rotation crop for pineapple, Mucuna pruriens var. utilis, showed that symphylids populations are highly aggregated following a negative binomial distribution. Finally, the method has been validated in plots of ‘MD-2’ pineapple to monitor the symphylids populations at different stages of development of the crop.