Spatial Pattern and Theoretical Sampling Number of Eggs of Banana Weevil Cosmopolites sordidus(Germar) in Hainan
The banana weevil Cosmopolites sordidus(Germar) occurred in the banana gardens and caused damage to banana plantations in Hainan.In order to find out the distribution and occurrence law of C.sordidus and guide the field sampling,the spatial distribution pattern and theoretical sampling frequency of C.sordidu eggs were investigated and analyzed,using related aggregation index formulae,power law of Taylor and m-m regression formulations of Iwao.The results showed that C.sordidus eggs presented an aggregated distribution under certain density condition,and that their spatial distribution accorded with the negative binomial distribution.The aggregation indexes were as follows:I0,m/m1,C1,Ca0.The simulation of the Taylor power model showed that the aggregating intensity of Cosmopolites sordidus increased with the population density.The calculation results of m-m regression formulations of Iwao showed that m and m were significantly correlated,that individuals of C.sordidus were mutually attracted,and that the correlation of the suitable sampling frequency(n) with density of eggs(m) and relative error(D) was:n=1/D2(1.3717/m+0.0463).