Potential damages, seasonal abundance and distribution of Empoasca terminalis Distant (Homoptera: Cicadellidae) on soybean in South SulawesiPotensi kerusakan, kelimpahan populasi dan sebaran Empoasca terminalis Distant (Homoptera: Cicadellidae) pada tanaman kedelai di Sulawesi Selatan

摘要

Plant damages caused by leafhopper, Empoasca terminalis Distant (Homoptera: Cicadellidae) onudsoybean were first encountered in 2007 in Makassar, South Sulawesi. The insect has been constantlyudassociated with soybean crops in the province ever since. The purposes of the present study were toud(i) evaluate potential yield loss attributable to the leafhopper in an experimental set up, (ii) seasonaludabundance of E. terminalis, and (iii) distribution of E. terminalis in all major soybean-producingudareas in the province. Potential yield loss due to the leafhopper was assessed in a field experimentudusing two large plots. One of the plots was kept leafhopper-free by weekly insecticide sprays; andudthe other plot was left unsprayed to allow leafhopper infestation to occur. Adult abundance wasudweekly monitored using a sweep net throughout the season. Nymph abundance was determined byuddirect count on the plant leaves. Leafhopper distribution was assessed through surveys conductedudin all major soybean-producing areas in South Sulawesi, from 2009???2013. The results of theudstudy showed that E. terminalis caused an average yield loss of 26% on susceptible crops withoutudinsecticide use. First leafhopper infestation in all planting seasons occurred two weeks after the plantudemergence. Rainfall negatively correlated with the leafhopper abundance. The leafhopper existedudin all major soybean production areas in the province. Therefore, our results confirmed the status ofudE. terminalis as an important soybean pest in the region. In addition, crops planted early in the dryudseason could escape from heavy leafhopper infestation.