SUITABILITY OF A NONHOST PALO VERDE FOR DEVELOPMENT OF STATOR LIMBATUS (HORN) (COLEOPTERA, BRUCHIDAE) LARVAE

In the southwestern United States, there are five species of palo verd es (Cercidium and Parkinsonia sp.; Fabaceae). Stator limbatus (Horn), a seed beetle, has been reared from four of these: Cercidium floridum (Benth.), C. microphyllum (Torr.) Rose & Johnst., Parkinsonia aculeata Linnaeus, and P. man a (Johnst.). However, despite extensive collecti ons in North and Central America, S. limbatus has never been reared fr om P. texana (A. Gray) S. Watson. We tested the suitability of P. texa na as a host for a Texas population of S. limbatus. Survivorship of S. limbatus on P. texana was high relative to the other pale verde speci es (except for C. microphyllum, on which survivorship was also high). Development time and body weight of emerging adults on P. texana were each approximately intermediate between those on C.floridum and P. acu leata (on which beetles developed slowly and emerged small) and C. mic rophyllum (on which beetles developed rapidly and became large adults) . These data indicate that P. texana is a suitable host for S. limbatu s and that, relative to other species of pale verde (except C. microph yllum), P. texana is a high-quality host. However, our study examines only the suitability of these pale verdes as hosts for S. limbatus in a controlled laboratory experiment. We discuss other hypotheses that m ay explain why P. texana is not used by S. limbatus in nature.