Aegidinus guianensis ( Westwood 1846 )

Colby, Julia, 2009, Monographic revision of the genus Aegidinus Arrow (1904) and generic phylogeny of the world Orphninae (Coleoptera: Scarabaeidae: Orphninae)., Insecta Mundi 2009 (76), pp. 1-41 : 20-22

Aegidinus guianensis ( Westwood 1846) Fig. 7 , 50-51 , 67 , 86-87 , 88

Aegidium guianense Westwood 1846:175 .

Aegidium steinheili Harold 1880:43 : synonym: Arrow 1904: 739.

Aegidinus guianensis (Westwood) : Arrow 1904: 739.

Type Material. Female Holotype from Cayenne , French Guiana ( BMNH). Examined.

Description. Male ( Fig. 86-87 ) (n = 7). Length 8.6-12.4 mm; width 4.5-6.5 mm. Color: Head, pronotum, and elytra reddish brown to brown. Legs and venter reddish brown. Head: Frons concave medially, impunctate or mostly impunctate (major) to punctate (minor); punctures sparse to moderately dense, small. Frontoclypeal suture effaced. Clypeus impunctate to moderately densely punctate or rugopunctate, punctures small. Anterior margin of clypeus with erect or nearly erect median horn (major) or tubercle (minor); carina extending from base of horn or tubercle laterally to each eye canthus. Pronotum: Surface punctate; punctures moderately dense to dense, moderate to large in size, concentrated on sides. Basal margin with bead and row of punctures, both becoming weak medially. Disc with subtriangular fovea, basolateral edge raised into a low, rounded tumosity on either side. Fovea punctate; punctures moderately dense to dense, moderate in size. Anterior margin of pronotum with conical or subtriangular, slightly transverse, median tubercle. Elytra: Punctures of striae elongate or vermiform, occasionally V- or Jshaped near base. Stria 1 obsolete at base. Lateral margin adjacent to humerus with 5-9 setose crenulations. Legs: Protibia with apical denticle. Genitalia: Fig. 7 , 50-51 .

Female. (n = 3). Length 9.1-10.1 mm; width 5.2-7.8 mm. The females differ from the males in the following respects: Head: Frons not concave. Frons and clypeus rugopunctate. Anterior margin of clypeus without horn or tubercle, with marginal bead. Pronotum: Disc with small, ovate, punctate depression; punctures moderately dense, small. Anterior margin of pronotum with median boss. Elytra: Lateral margin adjacent to humerus with 4-5 setae or setose crenulations. Legs: Protibia without apical denticle. Genitalia: Fig. 67 .

Diagnosis. This species is best distinguished from other species using the female and male genitalia. In females the unique combination of the interior process of the inferior genital sclerite produced into a finger like projection which is nearly as wide as long, and the presences of the accessory sclerites ( Fig. 67 ) is sufficient to separate this species from all other described species. The short lateral lobes of the male genitalia are positioned above the much longer median lobes ( Fig. 50-51 ), which is also a unique combination.

Distribution (Fig. 88): Brazil, Colombia, French Guiana. Ten specimens examined from BMNH, IRSB, and MNHN. BRAZIL: Unknown: (1). COLOMBIA (3): Unknown: Canoas (1); San Carlos (2). FRENCH GUIANA (1): Cayenne: Cayenne (1). UNKNOWN (5): San Carlos (4), Nare (1).

Temporal Distribution. Unknown.

Natural History. Nothing is known about the natural history of this species.

Figures

Figure 1-9. Scale bar = 1 mm. 1) Mouthparts exposed beyond clypeus. a) Labrum exposed beyond edge of clypeus. b) Single, external, lateral lobe on mandibles. 2) Apical spines of metatibia (indicated by arrows) separated by basal metatarsal segment. 3) Female genital sclerites of Aegidinus brasiliensis Arrow. a) Superior sclerite. b) Inferior sclerite. c) Interior process. 4). Female genital sclerites of A. oreibates Colby. a) Superior sclerite. b) Inferior sclerite. c) Accessory sclerite. 5) Male parameres (frontal view) of A. oreibates. a) Lateral lobe. b) Median lobe. 6) Male parameres (frontal view) of A. brasiliensis. a) Lateral lobe. b) Median lobe. 7) Male parameres and phallobase (lateral view) of A. guianensis (Westwood). a) Lateral lobe. b) Median lobe. c) phallobase. d) Basal piece of phallobase. 8) Attachment of first antennal club segment to stem offset (Hybalus sp.). 9) Attachment of first antennal club segment to stem not offset (Orphnus sp.).

Figures 50- 64. Male genitalia. Scale bar = 1 mm. 50) Parameres (frontal view) of A. guianensis. 51) Parameres and part of phallobase (lateral view) of A. guianensis. 52) Parameres (frontal view) of A. howdenorum. 53) Parameres and part of phallobase (lateral view) of A. howdenorum. 54) Ventral plate of A. howdenorum. 55) Lateral lobe of A. howdenorum. Arrow indicates notch. 56) Parameres (frontal view) of A. howeae. 57) Parameres and part of phallobase (lateral view) of A. howeae. 58) Parameres (frontal view) of A. oreibates. 59) Parameres and portion of phallobase (lateral view) of A. oreibates. 60) Ventral plate of A. oreibates. 61) Parameres (frontal view) of A. petrovi. 62) Parameres and part of phallobase (lateral view) of A. petrovi. 63) Parameres (frontal view) of A. teamscaraborum. 64) Parameres and part of phallobase (lateral view) of A. teamscaraborum.

Figures 65-77. Female genitalia, gonocoxites. Scale bar = 1 mm. 65) A. brasiliensis. 66) A. candezei. 67) A. guianensis. 68) A. howdenorum. 69) A. howeae. 70) A. oreibates. 71) A. simulatus. 72) A. sunidigea. 73-74) A. teamscaraborum. 75) A. tricornus. 76) A. unicus. 77) A. venezuelensis.

Figure 83- 87. Scale bar = 1 mm. 83) Lateral 3/4 habitus of A. cornutus. Arrow indicates tubercle. 84) Dorsal habitus of A. crypticus. 85) Lateral habitus of A. crypticus. Arrow indicates boss. 86) Lateral 3/4 habitus of A. guianensis. Arrow indicates tumosity.87) Dorsal habitus of A. guianensis. Arrow indicates fovea.