Occurrence of Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae) feeding on Cirsium pitcheri flowers

摘要

Diabrotica undecimpunctata howardi Barber (adult = spotted cucumber beetle, immature = southern corn rootworm, Coleoptera: Chrysomelidae) is a polyphagous pest found on a broad range for agricultural plants (Krysan 1986). The larvae are root feeders commonly found on plants in the families Cucurbiaceae (gourds and squashes), Poaceae (grasses, including Zea mays L.), and Fabaceae (legumes, including Medicago sativa L.), and can have significant impact on the crop yield depending on the agricultural system (Campbell and Emery 1967, Brust and House 1990). As an adult, D. u. howardi is among the most commonly encountered insects on gourd species (Cucurbita spp. and Lagenaria spp.) (Fronk and Slater 1956). Foliar damage by D. u. howardi can result in significant reduction in crop yield and floral damage includes feeding on anthers and filaments, reducing subsequent pollen production (Brewer et al. 1987, Sasu et al. 2010).