title: Geostatistics as a tool to study mite dispersion in physic nut plantations.
abstract: Spatial distribution studies in pest management identify the locations where pest attacks on crops are most severe, enabling us to understand and predict the movement of such pests. Studies on the spatial distribution of two mite species, however, are rather scarce. The mites Polyphagotarsonemus latus and Tetranychus bastosi are the major pests affecting physic nut plantations (Jatropha curcas). Therefore, the objective of this study was to measure the spatial distributions of P. latus and T. bastosi in the physic nut plantations. Mite densities were monitored over 2 years in two different plantations. Sample locations were georeferenced. The experimental data were analyzed using geostatistical analyses. The total mite density was found to be higher when only one species was present (T. bastosi). When both the mite species were found in the same plantation, their peak densities occurred at different times. These mites, however, exhibited uniform spatial distribution when found at extreme densities (low or high). However, the mites showed an aggregated distribution in intermediate densities. Mite spatial distribution models were isotropic. Mite colonization commenced at the periphery of the areas under study, whereas the high-density patches extended until they reached 30 m in diameter. This has not been reported for J. curcas plants before.
authors.affiliation: Federal University of Tocantins (UFT),PO BOX 66,Gurupi,State of Tocantins,Brazil.
authors.forename: J F
authors.initials: JF
authors.lastname: Rosado
authors.affiliation: Department of Entomology,Federal University of Viçosa,36570-900 Viçosa,MG,Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: Picanço
authors.affiliation: Federal University of Tocantins (UFT),PO BOX 66,Gurupi,State of Tocantins,Brazil.
authors.forename: R A
authors.initials: RA
authors.lastname: Sarmento
authors.affiliation: Department of Entomology,Federal University of Viçosa,36570-900 Viçosa,MG,Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Pereira
authors.affiliation: Federal University of Tocantins (UFT),PO BOX 66,Gurupi,State of Tocantins,Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Pedro-Neto
authors.affiliation: Department of Plant Production,Federal University of Viçosa,36570-900 Viçosa,MG,Brazil.
authors.forename: T V S
authors.initials: TV
authors.lastname: Galdino
authors.affiliation: Federal University of Tocantins (UFT),PO BOX 66,Gurupi,State of Tocantins,Brazil.
authors.forename: A
authors.initials: A
authors.lastname: de Sousa Saraiva
authors.affiliation: Federal University of Tocantins (UFT),PO BOX 66,Gurupi,State of Tocantins,Brazil.
authors.forename: E A L
authors.initials: EA
authors.lastname: Erasmo
mesh_terms: D000383:Agriculture; D063147:Animal Distribution; D000818:Animals; D031286:Jatropha / Q000469:parasitology*; D008925:Mites / Q000145:classification*; D008954:Models, Biological; D015233:Models, Statistical; D010935:Plant Diseases / Q000469:parasitology*; D011156:Population Density; D013997:Time Factors
keywords: Jatropha curcas; Polyphagotarsonemus latus; Tetranychus bastosi; spatial distribution maps