Theseus Stål, 1867

Photo © Emma Betts, Australian Museum

Type species:

Poecilometis modestus Stål 1865, by monotypy.

Number of Australian species:

Eight.

Extralimital Distribution:

No.

Australian Distribution:

Tropical and subtropical regions; New South Wales, Queensland, Northern Territory, South Australia, Victoria, Tasmania and Western Australia.

Biology:

Unknown.

Host(s):

Theseus grossi associated with Parkinsonia sp. [CAESALPINIACEAE].

Theseus modestus lyricus, Theseus modestus occidentalis and Theseus modestus modestus associated with Eucalyptus camaldulensis Dehnh. [MYRTACEAE].

Theseus modestus tasmanicus associated with Eucalyptus simmondsii Maiden [MYRTACEAE].

Diagnosis:

Colour

Dorsally pale brown ground colour with dark brown punctations and patches on the pronotum and scutellum, giving a dark, mottled appearance. Ventrally with a pale central band and medium to very dark brown lateral bands on the abdomen. Legs and antennae mottled pale to dark brown.

Texture

Densely and uniformly punctate.

Vestiture

Glabrous.

Structure

Body - Elongate-ovoid, dorsally flattened. Length 7.5 mm -12.5; width 3.5 mm -9.0 mm.

Head - Subtriangular, porrect (clypeus horizontally orientated), as long or longer than pronotum; jugae shorter than clypeus, pointed apically, laterally rounded; antennifer processes absent; five antennal segments, first antennal segment longer than the distance between the eyes, inserted into head below the mid-height and above the ventral margin of the eyes; bucculae elongate (posteriorly beyond antennifers); vertex cross-sectional shape flattened to slightly convex; labium extending onto abdomen, to fifth sterna or beyond, first labial segment longer than bucculae; eyes not stylate, directed laterally.

Pronotum - Calli present and well developed; anterior lobe surface flat; humeral angles subangulate; anterolateral margins simple and straight; posterolateral margins convex; posterior margin straight to convex.

Scutellum - Triangular, apex narrowly rounded; Y-shaped raised area present and well formed; lateral calli and medial callus present.

Thoracic sterna - Prosternum shallowly sulcate; mesosternum with a low raised keel; metasternum flat.

External efferent system - Evaporative scent gland covering about half the metepisternum; peritreme elongate, apically pointed.

Hemelytra - Macropterous, as long as abdomen; membrane veins linear and mostly subparallel.

Legs - Fore tibia sulcate.

Abdomen - Connexiva visible dorsally; laterotergites armed with small spines.

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