Caystrus Stål, 1861

Photo © Emma Betts, Australian Museum

Type species:

Paramecus marginiventris Stål, 1858 by monotypy.

Number of Australian species:

Two.

Extralimital Distribution:

Afrotropical Region - Nigeria; Australian Region - Indonesia (Maluku), Palau, Papua New Guinea (Bismarck Archipelago), Vanuatu; Oriental Region - Burma (= Myanmar), Indonesia (Java, Kalimantan, Sumatra), Philippines; Palaearctic Region - Syria.

Australian Distribution:

Tropical regions; Queensland, Northern Territory and Western Australia.

Biology:

Unknown.

Host(s):

Unknown.

Diagnosis:

Colour

Dorsally and ventrally medium orangey brown with darker punctations. Antennae pale to medium brown and concolourous. Legs medium orangey brown with darker punctations.

Texture

Densely and uniformly punctate.

Vestiture

Glabrous.

Structure

Body - Elongate, parallel-sided; dorsally convex. Length 6.1 mm - 10.1 mm; width 3.1 mm - 6.5 mm.

Head - Subtriangular, moderately dorsoventrally orientated, as long or longer than pronotum; jugae longer than clypeus, meeting (joined) in front of clypeus, apically rounded, laterally explanate; antennifer processes present; first antennal segment shorter than distance between the eyes; bucculae elongate (posteriorly beyond antennifers); vertex cross-sectional shape flattened; labium reaching between middle and hind coxae, first labial segment longer than bucculae; eyes not stylate, directed laterally.

Pronotum - Calli present and well developed; anterior lobe surface flat; humeral angles rounded; lateral margins explanate; anterolateral margins simple and straight to slightly sinuate; posterolateral margins straight to sinuate; posterior margin concave.

Scutellum - Triangular, apex broadly rounded; Y-shaped raised area present but low; lateral calli present; medial callus absent.

Thoracic sterna - Prosternum deeply sulcate with margin processes; mesosternum and metasternum sulcate.

External efferent system - Evaporative scent gland covering aprroximately half the metepisternum; peritreme very short, apically rounded and reflexed.

Hemelytra - Macropterous, shorter or equal to abdomen; membrane veins linear.

Legs - Fore tibiae sulcate.

Abdomen - Connexiva visible dorsally; laterotergites unarmed.

    
Copyright © Australian Museum 2002
Authors: Gerry Cassis, Emma Betts and Michael Elliott