The importance of semiochemicals for Diorhabda spp. (Coleoptera: Chysomelidae): biological control agents of invasive Tamarisk shrubs.
Several closely related species of the Eurasian saltcedar leaf beetle Diorhabda elongata species group (Coleoptera: Chrysomelidae) have been successfully introduced as biocontrol agents for saltcedar (Tamarix spp., Tamaricaceae) (DeLoach et al., 2003; 2004; Hudgeons et al., 2007; Bean, 2007; Tracy & Robbins, 2009). The non-native saltcedar is a rapid growing shrub causing considerable ecological and economic damage particularly in the riparian areas of arid and semi-arid western North America (Zavaleta, 2000; Shafroth et al., 2005). An existing practical need with this biocontrol program is the ability to monitor populations of the beetles in the field. Population properties such as establishment at release sites, distances of dispersal, and the ability to monitor the beetle movement into non-contiguous stands of saltcedar are important for land managers to understand, but are extremely difficult and tedious to measure.