Dicrania Le Peletier and Serville, 1828

Katovich, Kerry, 2008, A generic-level phylogenetic review of the Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae), Insecta Mundi 2008 (23), pp. 1-78 : 39-41

Dicrania Le Peletier and Serville, 1828

( Figure 82-87 )

Dicrania Le Peletier and Serville, 1828: 371 . Type species Dicrania nigra Le Peletier and Serville, 1828 , by monotypy. Monocrania Laporte, 1832: 410 . Type species Monocrania luridipennis Laporte, 1832 , by subsequent designation ( Evans 2003: 263). Synonymized by Dalla Torre (1913). Taxonomic Notes

The following generic diagnosis is based on two dissected homeotypes (one male and one female) of the presumptive syntype of the type species D. nigra located at the MNHC, and identified with a Le Peletier label .

Generic diagnosis

This genus is characterized by its elongate prementum, medially grooved; clypeus with anterior angles often produced into narrow teeth, strongly deflexed; pronotum, trapezoidal oblong, posterior margin often lobed; elytra ovate, widest in anterior 1/4, anterior angles often appearing toothed; metathoracic femur often broadly ovate; pygidium small, ovate.

Generic redescription

Measurements: Prothorax at widest point 5.2 mm, elytra at widest point 6.4 mm, length 13.0 mm.

Color and vestiture: Body of male black, dorsal surface glabrous, ventrally with a vestiture consisting of reddish setae. Female with body black, glabrous dorsally, prothorax red, ventrally with a vestiture consisting of reddish setae.

Head: Clypeus coplanar with frons, anterior angles often produced into narrow teeth, strongly deflexed ( Fig. 84 ); frons angled at 30 o; labrum in frontal view narrowly rectangular, weakly emarginate, labrum coplanar with clypeus; labium with prementum elongate, ventral surface medially with a broad, shallow groove ( Fig. 85 ); mandibles in dorsal view subtriangular, scissorial area rounded, membranous, molar area bluntly produced adorally; maxillary palpi with apical palpus ovate, equal in length to segments 2-3 combined, flattened ventrally, apex obtuse, forming a small sensory spot; antennae with 9 antennomeres, antennomeres 7-9 forming the elongate club, the length of which is equal to antennomeres 3-6 combined.

Prothorax: Pronotum trapezoidal, widest posteriorly, anterior angle obtuse, lateral margin rounded, posterior angle obtuse, posterior margin convex, medially lobed; prothoracic leg with coxa transverse; tibia dentate; pretarsus with claws divergent, equal in length, both claws narrowly split, upper lobe narrow, slightly shorter than lower lobe, lower lobe broad on individual claw, base of claw toothed.

Mesothorax: Scutellum subtriangular; elytra oblong, widest in anterior 1/4, narrowing in posterior 1/ 2, anterior angle produced into an acute anteriorly direct tooth ( Fig. 86 ), epipleuron with a slight bead, membranous margin in posterior 1/2, dorsal surface lacking striae, glabrous, anterior and posterior umbones slightly produced; pretarsus similar to prothoracic pretarsus.

Metathorax: Metathoracic leg with coxa widely separated; femur broadly ovate, widest medially; narrow proximally, tibia broadly clavate, widest distally, posteroventral margin with a pair of stout, long spurs, anterior spur short, arising above level of posterior spur tarsal articulation joint, posterior spur long, arising from same plane as tarsal articulation joint, posterior margin shallow, broadly grooved; pretarsus with claws similar to prothoracic and mesothoracic claws.

Abdomen: Ventrites 2-4 equal in length, sutures distinct, 5 th ventrite (= propygidium) broad, equal to length of ventrites 2-4 combined, medially ridged, posterior margin clear, membrane-like, ventrite and sternite of 5 th abdominal segment lacking a distinct suture, spiracle placed medially in a slight groove, 6 th ventrite equal to 1/2 length of 5 th ventrite; pygidium small, ovate, longer than wide ( Fig. 87 ).

Diversity and Geographic Distribution

Dicrania contains 43 species. Distribution is recorded from Argentina, Bolivia, Brazil, Colombia,

French Guiana, Guyana, Paraguay, and Peru. Regional keys were provided by Frey (1972a).

Figures

Figure 82-87. Dicrania nigra Le Peletier and Serville. 82) Dorsal habitus. 83) Left lateral view. 84) Head, dorsal view. 85) Prementum, ligula and labial palpi, ventral view. 86) Scutellum and elytra, dorsal view. 87) Pygidium, dorsal view.