The Mojave Desert of the southwestern U.S. is home to two pro-tected species of poppy in the genusArctomeconTorr. & Fr em. (Papaveraceae).A pollinator of these species is the specialist beePerdita meconisGriswold(Andrenidae) a specialist on poppy pollen. Recently, the easternmost population ofP. meconis, which was associatedwithA. humilisCoville in Utah, has become locally extinct, and other histori-cally associated bee pollinators have become scarce. Implicated in the disruptionof this pollination system is invasion by the Africanised honey bee. Here we report on the status ofP. meconisin historic populations associ-ated with congenerA. californicaTorr. & Fr em., 100 km west in Clark Co.,Nevada where the Africanised honey bee is also adventive. We surveyed flower visitors at eightA. californicapopulations in 2017, sixof which had been surveyed in 1995. In general, we found no disruptions of thehistoric pollination system ofA. californicadespite the presence of abundantAfricanised honey bees, which largely foraged at other flower species. The most likely cause of the disparate effects of the Africanised honey beein Utah and Nevada is livestock grazing. Grazing in Utah has been continuousfor over three decades and while cattle do not grazeA. humilis, they graze itsfloral competitors, forcing honey bees to forage on poppy flowers. In Nevada,protections afforded to the desert tortoise halted grazing approximately whenthe Africanised honey bee invaded, making diverse floral forage available forhoney bees.
Persistence of an imperiled specialist bee and its rare host plant in a protected area
Year: 2019
