Spatial patterns of the red palm weevil and applied entomopathogenic nematode Heterorhabditis bacteriophora

The distribution and abundance of red palm weevil (Rhynchophorus ferrugineus) within palm tree-infected stems at Ismaelia governorate, Egypt, were investigated. Taylor's power law was fit (P ≤ 0.01) to its larvae, pupae and/or adults. The slope value of this power law indicated the clumped distribution of these insect stages. Sample size optimisation needed to achieve a predetermined level of sampling error for the insect stages was calculated. Also, soil samples were taken after uniform application of entomopathogenic nematode Heterorhabditis bacteriophora strain EG1 to the soil under citrus tree canopies at the rate of 104 infective juveniles/400 cm2 plots, and assayed for the nematode using the Galleria bait method. At the first and second sampling dates, the nematode displayed contagious distribution and attained mean insect mortality of 15.3 and 4, respectively. At the third date of sampling, the nematode showed random distribution according to chi-squared test and caused 1.8 mean insect mortality. E...