Submitted to: Biocontrol Science and Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/16/2011
Publication Date: 10/20/2011
Citation: Cortes, E., Kirk, A., Goolsby, J., Moran, P.J., Racelis, A.E., Marcos-Garcia, M.A. 2011. Impact of the Arundo scale Rhizaspidiotus donacis (Hemiptera: Diaspididae) on the weight of Arundo donax (Poaceae: Arundinoideae) rhizomes in Languedoc southern France and Mediterranean Spain. Biocontrol Science and Technology. 21(11):1369-1373. Interpretive Summary: Arundo, also known as giant reed or carrizocane is a non-native, invasive giant grass that has invaded over 50,000 acres of habitat along the Rio Grande river and its tributaries and reservoirs in southern Texas and northern Mexico. This grass removes water from the river, making it unavailable for agriculture in this drought-prone region. In south Texas, arundo also hinders national border security activities, as well as recreational use of rivers and lakes. A tiny, immobile insect called the arundo scale was found feeding on arundo in its native range in France and Spain. The arundo scale feeds on the tuber-like rhizome, reducing shoot growth and weakening the plant. In this study, we dug up rhizomes from nine sites where arundo scales were feeding on arundo, and from nine sites where no arundo scales were present, all in southwestern France and southeastern Mediterranean Spain. The rhizomes of arundo from nine sites with arundo scale weighed 50% less than did rhizomes from nine sites with no arundo scale. This result showed that the arundo scale reduces below-ground growth of arundo rhizomes. Our previous studies showed that the arundo scale feeds and reproduces only on arundo. The arundo scale was released in early 2011 in south Texas, and has great potential as a biological control of arundo in the Lower Rio Grande Basin of Texas and Mexico and in other areas of North America invaded by arundo.
Technical Abstract: Arundo donax L. (Poaceae) is native to Mediterranean Europe and invasive in the Rio Grande Basin of North America. Rhizomes from nine sites in France and Spain infested with a candidate control agent, the armoured scale Rhizaspidiotus donacis (Hemiptera: Diaspididae) weighed 50% less than those from nine sites without scale.