PINYON PINES AS HOST PLANTS OF THREE PROCONIINE LEAFHOPPER SPECIES (HEMIPTERA: CICADELLIDAE: CICADELLINAE)

Host-plant relationships within the xylem-feeding leafhopper subfamily Cicadellinae (sharpshooters) are little known except for several economically important, mostly polyphagous species. Our fieldwork in the Southwestern United States has demonstrated an association of three species of the cicadelline tribe Proconiini with pinyon pines (Pinus, subsection Cembroides). Cuerna curvata Oman and Beamer and C obtusa Oman and Beamer are associated, respectively, with Pinus monophylla Torr. and Frem. and P. edulis Engelm. We also have confirmed an early report of Oncometopia alpha Fowler feeding on pines, especially P. edulis. Geographic distributions of these sharpshooters correspond to the distributions of their pine hosts. These data add to the few previously known cases of host-plant specialization in sharpshooters and for the first time document an association between sharpshooters and gymnosperms. The association is particularly remarkable because Our data Suggest that all three species use different angiosperrn hosts for oviposition. A dual use of angiosperms and gymnosperms (excluding use of the latter as overwintering sites) appears unique for Cicadellidae. We argue that pinyons provide a reliable source of xylem sap in the semiarid habitats of these sharpshooters but are unsuitable for oviposition.