Taxonomic revision and biogeography of the Tamarix-feeding Diorhabda elongata (Brullé, 1832) species group (Coleoptera: Chrysomelidae: Galerucinae: Galerucini) and analysis of their potential in biological control of Tamarisk

The primarily Palearctic Diorhabda elongata species group is established for five Tamarix-feeding sibling species(tamarisk beetles): D. elongata (Brullé, 1832), D. carinata (Faldermann, 1837), D. sublineata (Lucas, 1849) REVISEDSTATUS, D. carinulata (Desbrochers, 1870), and D. meridionalis Berti & Rapilly, 1973 NEW STATUS. Diorhabdakoltzei ab. basicornis Laboissière, 1935 and D. e. deserticola Chen, 1961 are synonymized under D. carinulata NEWSYNONYMY. Illustrated keys utilize genitalia, including male endophallic sclerites and female vaginal palpi andinternal sternite VIII. Distribution, comparative biogeography, biology, and potential in biological control of Tamarix inNorth America are reviewed. Diorhabda elongata is circummediterranean, favoring Mediterranean and temperate forestsof Italy to western Turkey. Diorhabda carinata resides in warm temperate grasslands, deserts, and forests of southernUkraine south to Iraq and east to western China. Diorhabda sublineata occupies Mediterranean woodlands from Franceto North Africa and subtropical deserts east to Iraq. Diorhabda carinulata primarily inhabits cold temperate deserts ofMongolia and China west to Russia and south to montane grasslands and warm deserts in southern Iran. Diorhabdameridionalis primarily occupies maritime subtropical deserts of southern Pakistan and Iran to Syria. Northern climatypesof D. carinulata are effective in Tamarix biological control, especially in the Great Basin desert. Diorhabda elongata isprobably best suited to Mediterranean woodlands of northern California. Northern climatypes of D. carinata may be bestsuited for central U.S. grasslands. Diorhabda sublineata, D. meridionalis, and southern climatypes of D. carinata and D. carinulata may each be uniquely suited to areas of the southwestern U.S.