• Title/Summary/Keyword: Cluming index

Search Result 1, Processing Time 0.016 seconds

Spatial Distribution Pattern of Ascotis selenaria (Lepidoptera: Geometridae) larvae in a Small-Scale of Citrus Orchard (소규모 감귤원에서 네눈쑥가지나방 유충의 공간분포 특성에 대한 이해)

  • Choi, Kyung San;Kim, Dong-Soon
    • Korean journal of applied entomology
    • /
    • v.52 no.3
    • /
    • pp.243-248
    • /
    • 2013
  • This study was conducted to understand the settlement process of Ascotis selenaria larvae into citrus orchards with respect to oviposition site and analysis of the spatial distribution pattern of the larvae. A. selenaria eggs were not found on citrus trees in field and green house, but not on citrus trees in the field. A. selenaria larvae showed a significant clump distribution in the greenhouse. In the open citrus field, the index of dispersion was around 1.0 in most cases, with a weak clumping degree. However, the d-statistic was between -1.96 and 1.96, indicating a statistically significant random distribution. In addition, the Green's index (a clumping index) was very low in all cases, even though the clump distribution was accepted. for most samples, the probability distribution of larval frequency in the field satisfied the probability distribution functions of Poisson (random pattern) and the negative binomial (clump pattern) distribution. In addition, the temporal distribution of the larvae in the open field showed a pattern which was formed by colonizers from outside oviposition sites. Further, the difference in larval spatial distribution between field and greenhouse orchards was discussed.