Spatial distribution of Cheilomenes sexmaculata (Fabricius), an important predator of bean aphid, Aphis craccivora Koch in green gram

Field studies were conducted to study the spatial distribution of Cheilomenes sexmaculata (Fabricius) during summer and kharif seasons, 2009 at instructional cum research farm of Assam Agricultural University, Jorhat, Assam. Various indices of dispersion were used to study the distribution pattern. In both seasons, the variance to mean ratios were found to be less than unity, dispersion parameter ‘k’ was less than 8 and David and Moore's indices of clumping were negative. Also, Lloyd's indices of mean crowding were less than mean and indices of patchiness were less than unity, indicating positive binomial (regular) distribution of C. sexmaculata at both larval and adult stages.