Bionomics of Haplaxius crudus (Homoptera: Cixiidae) 12

Abstract

Haplaxius crudus nymphs feed and live in the thatch layer and on the roots of St. Augustinegrass, bahiagrass, centipedegrass, bermudagrass, paragrass, yellow nutsedge, broomsedge, foxtail, and other sedges. Secretions from the abdominal wax glands protect the nymphs from wetness, disease, and predators. Average nymph size after each molt at 24°C was 0.80, 1.35, 1.80, and 2.47 mm for 4 respective molts. No differences in size were noted at 30°C. Wingpad development between each molt is a unique characteristic for identifying nymphal age. All nymphal instars developed more rapidly at 30° than at 24°C. Cool temperature (15°C) had an adverse effect on nymph development. Large nymphs survived an extended period without feeding. Eggs were 0.5–0.6 mm in length and 0.15–0.20 mm in width with one blunt end. Parthenogenic reproduction was not observed. The mean life span for adult males on St. Augustinegrass was 7.3 days and 7.8 days for adult females. The mean generation time at 30°C was 52.6 days and 80.8 days at 24°C. The adult H. crudus survived 37 and 50 days on coconut and veitchia palms, respectively. Coconut cultivars differed significantly in numbers of H. crudus attracted. The numbers of adults attracted to palm differed significantly among seasons. H. crudus was found in palms more in the evening hours than in the morning hours.