Herbarium specimens provide historical evidence of Cardiaspina jerramungae (Hemiptera: Psylloidea, Aphalaridae) outbreaks on Eucalyptus occidentalis in the Lower Great Southern of Western Australia

Abstract

AbstractIn 1982, a new species of psyllid, Cardiaspina jerramungae, reached outbreak levels on Eucalyptus occidentalis. The primary host species grows in remnant stands in the Lower Great Southern region of Western Australia and until this event was not recognised to be associated with insect outbreaks. Herbarium specimens, a largely unexploited source of data for temporal and spatial history of ecological interactions between plant hosts and insect herbivores, provided evidence of historical insect outbreaks. Evidence of C. jerramungae was traced through herbarium specimens of the preferred hosts, E. occidentalis and Eucalyptus utilis. The earliest evidence of this insect was found on a 1901 specimen of E. occidentalis. There was also evidence of a high population in 1960. Further outbreaks of C. jerramungae are likely, with consequences for the health of its primary host, although their periodicity and duration are unpredictable.