Ceratolontha Arrow, 1948

Katovich, Kerry, 2008, A generic-level phylogenetic review of the Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae), Insecta Mundi 2008 (23), pp. 1-78 : 29-30

Ceratolontha Arrow, 1948

( Figure 49-53 )

Ceratolontha Arrow, 1948: 372 . Type species Ceratolontha venezuelae Arrow, 1948 , by monotypy.

Taxonomic Notes

The following generic diagnosis is based on a dissected female paratype of the type species, C. venezuelae (BMNH) .

Generic diagnosis

This genus is characterized by its elongate body, clypeus in males forming a pair of horns, in frontal view very narrow, dorsolateral angles strongly projecting upwards into a short horn, in dorsal view anterior angles strongly produced anteriorly and dorsally, forming a pair of long horns, dorsal surface with a deep medial U-shaped depression in males; quadrate prementum, ventral surface with a raised Ushaped transverse ridge, medially with a raised anterior ridge.

Generic redescription

Measurements: Prothorax at widest point 6.0 mm, elytra at widest point 6.5 mm, length 15.0 mm.

Color and vestiture: Body brown, surface with vestiture consisting of scattered fine yellow setae.

Head: Clypeus not coplanar with frons, clypeus in males forming a pair of horns ( Fig. 51 ), in frontal view very narrow, dorsolateral angles strongly projecting upwards into a short horn, in dorsal view anterior angles strongly produced anteriorly and dorsally, forming a pair of long horns; frons angled 10 o; labrum in frontal view narrowly ovate, deeply emarginate, labrum not coplanar with clypeus; labium with prementum quadrate, ventral surface with a raised U-shaped transverse ridge in posterior 3/4, medially with a raised ridge in anterior 1/2 ( Fig. 52 ); mandibles rectangular, scissorial area bluntly produced, medially with a small tooth, molar area bluntly produced; maxillary palpi 4-segmented, 4 th segment narrowly ovate, apex acute, elongate, equal to length of segments 1-2 combined; antennae with 9 antennomeres, antennomeres 7-9 forming the elongate club, club equal to length of antennomeres 2-6 combined.

Prothorax: Pronotum oblong, transverse, widest medially, anterior angle acute, lateral margin convex, posterior angle obtuse, posterior margin weakly convex, medially lobed ( Fig. 53 ), dorsal surface strongly rounded; prothoracic leg with coxa transverse; tibia bidentate; pretarsus with claws divergent, equal in length, both claws narrowly split, upper lobe narrow, lower lobe broad on individual claw.

Mesothorax: Scutellum semicircular; elytra longer than wide, widest in anterior 1/4, epipleuron flattened, medially grooved, margin lined with a slight membrane, dorsal surface flattened, three weak striae, intervals shallowly punctured, punctures with small white setae, anterior and posterior umbones moderate; pretarsus similar to prothoracic pretarsus.

Metathorax: Coxa clearly separated; femur narrowly ovate, width uniform; tibia narrowly rectangular, narrow proximally, widest medially, posteroventral margin with pair of long, stout spurs, spurs equal in length, arising at same level as tarsal articulation joint, posterior margin with broad, shallow, U-shaped groove; pretarsus with claws similar to claws of prothoracic legs.

Abdomen: Ventrites 2-4 subequal in length, 5 th ventrite (= propygidium), equal to length of ventrites 3-4 combined, ventrite and sternite of 5 th abdominal segment with a weak fold, complete suture lacking, spiracle located medially; 6 th ventrite equal to length of 4 th ventrite, posterior margin membranous; pygidium subtriangular, wider than long, posterior margin rounded.

Diversity and Geographic Distribution

Ceratolontha is monotypic, with C. venezuelae known only from Venezuela.

Figures

Figure 49-53. Ceratolontha venezuelae Arrow. 49) Dorsal habitus. 50) Left lateral view. 51) Clypeus, labrum and pronotum, lateral view. 52) Prementum, ligula and labial palpi, ventral view. 53) Pronotum, dorsal view.