Spatial distribution of Rhynchophorus palmarum L. (Coleoptera: Curculionidae) in oil palm, Roraima State, Brazil

Abstract

Oil palm (Elaeis guineensis Jacq.) is an African palm that is distinguished by its elevated oil production per unit area, however, fitossanitary problems are one of its the main drawbacks. Thus, this study aimed to evaluate the spatial distribution pattern of the Rhynchophorus palmarum (L) (Coleoptera: Curculionidae) in oil palm plantations with geo-statistical procedures in the south of the state of Roraima, Brazil. The 25 ha of experimental area is located in the municilaity of São João da Baliza, RR, where 24 samples were carried out in the period from September 2013 to August 2014. For the insects collection, a buckettype trap with food attractant (sugarcane) was placed in each one of the 100 sampling points. Analyses of spatial variability and spatial dependence were held by the incorporation of geo-statistical procedures based on spatial modeling techniques by semivariagrams. The spatial distribution of the R. palmarum is aggregated with spatial dependence described by the spherical model, forming clusters of 100 to 210 m radius. It was observed that R. palmarum infestation takes place both in the center just as on the edges of the plantation, with later dissemination to the entire area. The maximum range found in the study was of 210 m, with an area of influence of 13.9 ha.