Development of Cuerna yuccae Oman & Beamer, 1944 (Hemiptera: Cicadellidae) on Joshua trees after summer rainfall

Abstract

Cuerna yuccae Oman & Beamer, 1944 (Hemiptera: Cicadellidae) is a leafhopper found primarily on Joshua trees, Yucca brevifolia Engelmann (Asparagaceae), but also reported on other species of Yucca (Oman & Beamer 1944, Nielson 1965). Cuerna includes 25 species distributed across North and Central America with most species in the western United States (Krishnankutty et al. 2015). The genus is in the tribe Proconiini in the subfamily Cicadellinae, or sharpshooters, medium to large leafhoppers known for their active and evasive behavior. Female C. yuccae are 7.2–8.0 mm in length, and both sexes are gray or black with yellow spots on the head, pronotum, and scutellum and reddish forewings (Fig. 1, Nielson 1965, Krishnankutty et al. 2015). Yucca brevifolia is an arborescent monocot that can reach 12 m in height and is found at elevations of 600–1500 m in southern Nevada and adjacent southern California, western Arizona, and southwestern Utah (Webber 1953, Benson & Darrow 1981). The plants’ thick, branching stems terminate in rosettes of narrow, 15–35 cm long stiff and pointed leaves (Fig. 1). Adult C. yuccae have been collected across the range of Y. brevifolia from April to October (Nielson 1965), and I have also found adults in southern Nevada during December, February, and March. The life cycle of C. yuccae has not been described. All North American leafhoppers develop through the stages of egg, five nymphal instars, and adult (Oman 1949). Nielson & May (1975) reported the life stages and development times of Cuerna arida