Abstract:

In order to find out the distribution and occurrence law of Mecyslobus roelofis larvae in sweet potato fields, the spatial distribution pattern and theoretical sampling frequency were investigated and analyzed in 2011, using related aggregation index formulae, Taylor’s power law and Iwao’s m*-m model. The results showed that the spatial pattern of Mecyslobus roelofis larvae belonged to assemble distribution in sweet potato fields. The aggregating intensity of Mecyslobus roelofis larvae increased with the population density, but the space of the colony became smaller. The larva’s aggregation in sweet potato fields was due to environmental factors. Base on the data of spatial distribution, the optimum theoretical sampling number of the larva could be obtain from the formula [n=1.962/D2 (1.1047/m+0.8737)] and Iwao’s model [T0(n)=0.2n ± 0.4759 ] of sequential sampling.