Immatures of the New World treehopper tribe Amastrini (Hemiptera, Membracidae, Smiliinae) with a key to genera Author McKamey, Stuart H. Author Wallner, Adam M. Author Porter, Mitchell J. text ZooKeys 2015 524 65 87 http://dx.doi.org/10.3897/zookeys.524.5951 journal article http://dx.doi.org/10.3897/zookeys.524.5951 1313-2970-524-65 B34E97F130E341BDA03273BDDF60020A B34E97F130E341BDA03273BDDF60020A Taxon classification Animalia Hemiptera Membracidae Vanduzea Goding Figs 35-37, 38-41, 61-64 Diagnosis . Head and thorax without scoli; meso and metanota with enlarged cluster of chalazae (Fig. 40), terga III-VIII each with pair of short, densely chalazal scoli (Fig. 41). Nymphal description. Overall body. Chalazal setae long; dorsal contour of abdomen in lateral view curvilinear; scoli parallel. Head. Scoli absent; chalazal setae simple, hairlike. Prothorax. Without pre- or postmetopidium scoli; posterior extension of pronotum surpassing anterior but no posterior margin of metanotum. Mesothorax. With paired cluster of enlarged chalazae dorsally; scoli absent; forewing pad costal margin straight, without costal chalazae; forewing pad densely covered with chalazae, chalazal setae long. Metathorax. With paired cluster of enlarged chalazae dorsally. Legs. Chalazae of tibia on lateral margins and many on dorsal surface. Abdomen. Terga III-VIII ventrolateral margins without enlarged chalazae; terga III-VIII dorsal scoli all subequal in size, tallest dorsal scoli 2-4 5 basal width; tergum IV dorsal scoli directed dorsally; terga III-VIII lateral rows not manifested; tergum III with paired apically acute scoli dorsally. Segment IX. Dorsal length subequal to combined length of remaining visible abdominal terga or at least V-VIII; without dorsal enlarged chalazae or scoli at apex; ventral extension subequal to dorsal extension. Material examined. Vanduzea arquata Say, 1 adult, 1 nymph, USA: Maryland, Frederick County, Frederick, 2 August 1994, M.J. Rothschild, near Linden, Virginia, March 28, 1922 (USNM), 1 nymph, 1 adult, USA: North Carolina, Wake Co., Raleigh, 8 Aug 1986, S.H. McKamey lot #86-0808-2 (USNM), Robinia pseudoacacia L., Fabaceae ; Vanduzea laeta Goding, 1 adult, 4 nymphs, USA: Tuscon, Arizona, 5-12-29 E.D. Ball (USNM); Vanduzea nolina Ball, 1 adult, 1 nymph, Nogales, E.D. Ball, Ar., 8-14-35, 7-30-37 (USNM); Vanduzea segmentata Fowler, 1 adult, 1 nymph, USA: Brownsville, Texas, 5-3-38, Los Angles Co., California (USNM); Vanduzea triguttata (Burmeister), 1 adult, 1 nymph, USA: Tucson, Arizona, June 16, 1933, P.W. Oman, (USNM). Vanduzea sp. 1, 1 adult, 1 nymph, ECUADOR (USNM). Distribution. Northern South America northward to Canada, Hawaii. Biology. Similar to other Amastrini genera, Vanduzea aggregate on their host plants and some species, for example Vanduzea arquata (Funkhouser, 1915), are tended by Formica ants ( Funkhouser 1915 , Fritz 1983 , Crocroft 2003 ). These treehoppers feed on herbaceous and woody dicot hosts, such as Albizia julibrisson , Citrus sp., Melilotus alba , Bidens alba , Eupetorium capillofolium , Lespedeza sp., Quercus sp., and Robinia pseudoacacia ( Kopp and Yonke 1973 c, Dietrich et al. 1999 ). Vanduzea is a common and widespread genus in the Nearctic, Neotropics, West Indies, and has been introduced to the Hawaiian Islands ( Deitz and Wallace 2012 ). SHM has observed them in Hawaii tended by ants, which are also introduced. Discussion. The nymph of Vanduzea laeta has unequal but not posteriorly increasing or decreasing sizes of abdominal scoli with greatly elongate scoli on terga IV and V (Fig. 36). In contrast, Vanduzea laeta nolina has abdominal scoli that are subequal in length and all short (Fig. 37), so the latter is here elevated to specific status.