Gastrohoplus Moser, 1921

Katovich, Kerry, 2008, A generic-level phylogenetic review of the Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae), Insecta Mundi 2008 (23), pp. 1-78 : 43-44

Gastrohoplus Moser, 1921

( Figure 94-99 )

Gastrohoplus Moser, 1921b: 165 . Type species Gastrohoplus mirabilis Moser, 1921b , by monotypy.

Taxonomic Notes

The following generic diagnosis is based on a single dissected syntype of the generic type species G.

mirabilis (ZMHB) .

Generic diagnosis

This genus closely resembles Macrodactylus , it is characterized by the quadrate pronotum, widest in the posterior 1/4, anterior angles toothed; males with propygidium elongate laterally, forming two long subtriangular plates.

Generic redescription

Measurements: Prothorax at widest point 3.25 mm, elytra at widest point 5.0 mm, length 10.0 mm.

Color and vestiture: Head black, vestiture consisting of whitish scale-like setae and fine orange setae, pronotum medially with white, scale-like setae, elytra brown, with a vestiture consisting of fine orange setae, abdomen dark brown, covered with a vestiture consisting of short, white setae.

Head: Clypeus coplanar with frons; frons angled at 30 o; labrum in frontal view narrowly ovate, weakly emarginate, labrum coplanar with clypeus; labium with prementum rectangular, elongate (2X longer than wide), ventral surface with medial groove ( Fig. 96 ); mandibles in dorsal view rectangular, scissorial area reduced to a membrane, lined with dense setae, molar area well developed; maxillary palpi with apical segment conical, equal to length of segments 1 and 2 combined, apex obtuse; antennae with 9 antennomeres, antennomeres 7-9 forming the club, lamellae thin, elongate, equal to antennomeres 3-6 combined.

Prothorax: Pronotum quadrate, widest in posterior 3/4, anterior angles acute, appearing toothed, lateral margin concave in anterior 1/2, convex in posterior 1/2, posterior angle acute, appearing toothed, posterior margin concave, medially lobed ( Fig. 97 ); prothoracic leg with coxa elongate; tibia lacking a tooth, ventral margin with a small spur in distal 1/4; pretarsus with claws divergent, equal in length, both claws broadly split, upper lobe broad, longer than lower lobe, lower lobe broad on individual claw.

Mesothorax: Scutellum subtriangular; elytra longer than wide, widest medially, elytral epipleuron narrowly flattened, dorsal surface with striae indistinct, anterior umbone strongly developed, posterior umbone weakly developed; pretarsus similar to prothoracic pretarsus.

Metathorax: Metathoracic leg with coxa narrowly separated; femur ovate, widest medially, narrowing distally; tibia vase-shaped, narrow proximally, widest in proximal 1/4, posteroventral margin with two spurs arising from same plane as tarsal articulation, posterior margin lacking groove; pretarsus with claws similar to prothoracic and mesothoracic legs.

Abdomen: Ventrites 2-4 subequal in length, 5 th visible ventrite (= propygidium) 1.5X length of 4 th ventrite, horizontal ridge medially, ventrite and sternite of 5 th abdominal segment lacking a suture, spiracle placed medially, male with propygidium elongate laterally, forming two long subtriangular plates ( Fig. 98 ); 6 th ventrite equal in length to 5 th ventrite, posterior margin weakly concave; pygidium subtriangular, longer than wide, posterior margin rounded ( Fig. 99 ).

Diversity and Geographic Distribution

Gastrohoplus is monotypic, with G. mirabilis known only from Brazil.

Figures

Figure 94-99. Gastrohoplus mirabilis Moser (female). 94) Dorsal habitus. 95) Left lateral view. 96) Prementum, ligula and labial palpi, ventral view. 97) Pronotum, dorsal view. 98) Propygidium and pygidium, left lateral view. 99) Pygidium, dorsal view.