Potential distribution area of the Mexican bean beetle, Epilachna varivestis (Coleoptera : Coccinellidae) in Japan, estimated from its high-temperature tolerance
Y. Shirai et K. Yara, Potential distribution area of the Mexican bean beetle, Epilachna varivestis (Coleoptera : Coccinellidae) in Japan, estimated from its high-temperature tolerance, APPL ENT ZO, 36(4), 2001, pp. 409-417
Thermal responses in regard to female oviposition and larval development we
re investigated in the invasion population of the Mexican bean beetle, Epil
achna varivestis whose presence was initially confirmed in Yamanashi and Na
gano Prefectures, central Japan in 1997. Oogenesis in the female was inhibi
ted when exposed to 27.5 degreesC for five continuous days. Larval developm
ent was inhibited markedly at 30 degreesC, and survival rate declined to ne
arly 0% when exposed to 32.5 degreesC for more than five days. Based on the
se high-temperature stresses and the 30-year average temperature data in Ja
pan (1961-1990), we estimated the potential distribution area of E. varives
tis in Japan. It is predicted that E. varivestis will be less abundant in t
he south-western areas of central Japan, while this beetle could survive ef
ficiently and maintain a high population level in the mountainous areas of
central Japan, and in almost all of northern Japan (Tohoku and Hokkaido).