Amastris Stal

McKamey, Stuart H., Wallner, Adam M. & Porter, Mitchell J., 2015, Immatures of the New World treehopper tribe Amastrini (Hemiptera, Membracidae, Smiliinae) with a key to genera, ZooKeys 524, pp. 65-87 : 71

Taxon classification Animalia Hemiptera Membracidae

Amastris Stal Figs 12-20, 42-49, 65

Diagnosis.

Usually with the following characters: head and thorax without scoli; posterior extension of pronotum not surpassing anterior margin of metanotum; terga III-VIII with paired, short, chalazal scoli of subequal size; body including wing pad densely covered with chalazae bearing short setae.

Nymphal description.

Overall body. Chalazal setae short; dorsal contour of abdomen in lateral view curvilinear or linear; scoli parallel (except tightly appressed in Amastris sp. 5). Head. Scoli absent; chalazal setae simple, needlelike. Prothorax. Pre- and postmetopidum without scoli; posterior extension of pronotum not surpassing anterior margin of metanotum. Mesothorax. With paired enlarged chalazae dorsally; scoli absent; forewing pad costal margin straight or sinuate, with enlarged chalazae only along base; forewing pad chalazae sparse, chalazal setae short; lateral rows of abdomen not extending onto meso- and metathorax. Metathorax. Dorsally with paired scoli; scolar chalazae bearing tuberculate chalazae; scolar directed dorsally or posteriorly; dorsal scoli relative size to themselves scoli 2-4 5 basal width. Legs. Chalazae of tibia on lateral margins and many on dorsal surface. Abdomen. Terga III-VIII ventrolateral margins with single enlarged chalaza; terga III-VIII dorsal scoli all subequal in size, tallest about 2-4 5 basal width, apices acute; tergum IV dorsal scoli basally directed dorsoposteriorly, distally directed posteriorly; terga III-VIII with 2 lateral rows of enlarged chalazae. Segment IX. Dorsal length subequal to combined length of segments IV-VIII; apex without dorsal enlarged chalazae or scoli; ventral extension subequal to dorsal extension.

Material examined.

Amastris elevata , 1 nymph, 1 ant, GUYANA: Demerera Co., nr Lukabuna Crk, Georgetown-Linden Hwy, ca km55, 13 July 1987, elev. ca 50m. S.H. McKamey lot #87-14c (USNM); Amastris obtegens (Fabricius), 1 adult, 1 nymph, Mazaruni-Potaro, ca 13 rd km S Bartica, ca 100m, 17 August 1987, S.H. McKamey lot#87-0817-g (USNM); Amastris sp. 1, 1 adult, 1 nymph, Mazaruni-Potaro, Bartica, 94m. 8 August 1987, S.H. McKamey lot#87-140a (USNM); Amastris exigua Broomfield, 1 adult, 1 nymph, ECUADOR: Pastaza-Puyo, 960m, 2 March 1986, S.H. McKamey lot#86-0302-34 (USNM); Amastris sp. 2, 1 adult, 1 nymph, Napo. Coca. 9-19 February 1986, 249m. McKamey, Coll. #86-0212-10 (USNM); Amastris sp. 3, 1 adult, 1 nymph, Moroni-Santigao. Macas, 9 May 1986, 1070m, S.H. McKamey lot# 86-0509-2 (USNM). Amastris sp. 4, 1 adult, 1 nymph, GUYANA, Demerara Co., ca 46 rd km S of Linden, ca. 70m, 13-Aug 1987, S.H. McKamey lot#87-160a,b USNM); Amastris sp. 5, 1 adult, 1 nymph, Pichincha, Tinalandia, 16 km E Sto. Domingo de los Colorados. 16-20 April 1986. ca 600m, S.H. McKamey lot#86-0419-2 (USNM); Amastris sp. 6, 2 adults, 1 nymph, Napo, Limoncocha, 22 August 1988, S.H. McKamey coll#88-42d (USNM).

Distribution.

Brazil and Peru northward to the United States.

Biology.

As far as known, all Amastris are subsocial, with the female parent sitting atop her uncovered egg mass, which are inserted into stems of the host, and tending her nymphs after hatching (Fig. 65). Nymphal aggregations are almost always ant-attended. Ant specimens pinned under vouchers include Camponotus , Crematogaster , and Azteca .

Discussion.

Broomfield (1976) revised this large genus, but many species remain undescribed, including some of the specimens examined here. Nymphs of the genus Amastris Stål are difficult to characterize because some species bear no distinguishing enlarged chalazae or scoli or other features and thus resemble some taxa of other Smiliinae tribes and even other subfamilies.