Distribution and abundance of the maize orange leafhopper Cicadulina bipunctata (Melichar) (Homoptera: Cicadellidae) in Kikuchi, Kumamoto, Japan, in 2004

Abstract

Cicadulina bipunctata (Melichar) (Homoptera: Cicadellidae) induces maize wallaby ear disease. Following the initiation of biyearly plantings of forage maize in Kumamoto, Japan, in 1988, C. bipunctata became a pest of the second planting. Recently, the area of forage maize fields damaged by C. bipunctata has expanded in Kikuchi, Kumamoto. To clarify the current damaged area and the field life cycle of C. bipunctata, we surveyed distribution, abundance, and seasonal occurrence of C. bipunctata in forage maize fields and surrounding areas in Kikuchi, in 2004. C. bipunctata inhabited most of the cultivated area of forage maize in Kikuchi, and the density was high enough to cause severe damage at many sites. In neighboring fields, C. bipunctata occurred mainly from July to December, with a peak of occurrence in October. A possible factor affecting the recent expansion of damaged area and outbreaks of C. bipunctata is the relatively low winter mortality of C. bipunctata due to the high average temperature in recent years, attributable to global warming.