The abundance of lycaenid, Shijimiaeoides divinus asonis is reduced by environmental change in some habitats in the Aso area. Our investigation of the influence of pasturage and grassland burning upon the abundance of insects and spiders on the host plant, Sophora flavescens indicated the following facts: (1) Collected from the host plant of this butterfly were 10 families, 19 species of spider. Thomisid spiders were most aboundant, followed by araneid spiders. (2) A number of spiders preyed on this butterfly: Linyphia radiata (Linyphiidae), Agelena limbata (Agelenidae), Neoscona adianta (Araneidae), Tibellus tenellus (Philodromidae), Xysticus ephippiatus (Thomisidae), Misumenops tricuspidatus (Thomisidae), Carrthotus xanthogramma (Salticidae). (3) The insect fauna on the host plant of this butterfly was from 41 families, 56 species from April to July. Dominant species were larvae of this butterfly, Formica japonica (Formicidae) and Camponotus japonicus (Formicidae). (4) Under the non-pasturage or non-grassland burning, the population of larvae of this butterfly, F. japonica and C. japonicus decreased markedly. On the other hand, the spider density of the field under the non pasturage or non fire burning was higher than that of the field under the pasturage and grassland burning, especially Thomisidae. These results suggested that the number of ants and larvae of this butterfly on the host plant decreased in the habitat under the non-pasturage or non-grassland burning. The population of this butterfly decreased in these environments.
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