Life history evolution of the andromeda lace bug, stephanitis takeyai, induced by the simplification of vegetation in nara park, caused by browsing of the sika deer, Cervus nippon

Abstract

In Nara Park, population density of conserved sika deer has been very high for several hundreds of years. This caused vegetation simplification to toxic and unpalatable plants. The andromeda lace bug, Stephanitis takeyai, usually alternates its host plants seasonally. However, in Nara Park, one of the host plants, Lyonia ovalifolia is very scarce so that S. takeyai lives on the other host, Pieris japonica throughout the year. I investigated the long-term genetic change in life history characteristics caused by the loss of seasonal host alternation in the Park. Reared at same condition, individuals from Kyoto population, where the bug alternates the hosts, preferred L. ovalifolia more than Nara individuals did. The former attained lower fecundity and larger relative wing length. Lower fecundity was considered as the cost of migration apparatus.