The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape, 2006 (Hemiptera: Thau mastocoridae), is a threat to commercial plan tations of Eucalyptus (Myrtales: Myrtaceae) in Argentina, Australia, Brazil, Chile, Kenya, South Africa, Uruguay and Zimbabwe (Carpintero & Dellape 2006; Martinez & Bianchi 2010; Nadel et al. 2010; Noack et al. 2011). Thaumastocoris peregrinus is a typically gregarious sucking insect with nymphs and adults of different generations overlapping throughout the year (Noack & Rose 2007; Wilcken et al. 2010). Adults are about 3 mm long, with a flattened light brown body (Noack et al. 2011). Females lay about 60 black eggs usually in clusters on leaves, branches and at the base of host plant trunks (Jacobs & Neser 2005; Noack & Rose 2007).

The high reproductive capacity of T. peregrinus facilitates rapid colonization and infestation. The pest initially causes silvering of the leaves, which subsequently shift to brown and red coloration, and this makes the trees look bronzed (Jacobs & Neser 2005). These canopy coloration changes al low identification of the presence of T. peregrinus before leaf drop and plant death occurs. The mechanism that induces plant death is not known, but the symptoms of feeding by nymphs and adults of T. peregrinus on eucalyptus leaves are similar to those of Cardiaspina psyllids (He miptera: Psyllidae)(Woodburn & Lewis 1973; Crawford & Wilkens 1996). The psyllids insert their stylets through the apertures of stomata to reach food supply causing cell degeneration of the mesophyll tissue that resembles the process of leaf senescence (Crawford & Wilkens 1996). The use of the systemic insecticide imidaclo prid injected into the trunk has been shown effec tive to control T. peregrinus in field tests (Noack et al. 2009), but chemical control in forest planta tions is questionable due to potentially adverse environmental impacts and high costs (Zanuncio et al. 1994). Thus, biological control, such as the introduction or enhancement of populations of