Morphogenia struhli, Parker, Joseph, 2014

Parker, Joseph, 2014, Morphogenia: a new genus of the Neotropical tribe Jubini (Coleoptera, Staphylinidae, Pselaphinae) from the Brazilian Amazon, ZooKeys 373, pp. 57-66 : 59-63

Morphogenia struhli sp. n.

Type material.

Holotype ♂: "88 1 // Leaf litter, Winkler method. Terra firmé fst. // BRAZIL: Manaus, A.M. INPA/Smithsonian Res. 2°25'S, 59°50'W, R. Didham, i. 1994 // BMNH{E} 2003-84.". Paratypes (2 ♀♀): "89 7 // Leaf litter, Winkler method. Terra firmé fst. // BRAZIL: Manaus, A.M. INPA/Smithsonian Res. 2°25'S, 59°50'W, R. Didham, i. 1994//BMNH{E} 2003-84 // (pink label) 0749". "68 12 // Leaf litter, Winkler method. Terra firmé fst. // BRAZIL: Manaus, A.M. INPA/Smithsonian Res. 2°25'S, 59°50'W, R. Didham, i. 1994 // BMNH{E} 2003-84". All material is deposited in the Coleoptera collection of the Department of Entomology, Natural History Museum, London.

Description.

Body length 2.9 mm (Fig. 1). Holotype male somewhat teneral; body colour of female paratypes dark reddish-purple (e.g. Figs 17, 19) with appendages lighter in colour. Dorsal regions shiny, with shallow punctures and sparse setae in most areas.

Head: Length 0.71 mm from occipital constriction to clypeus; width across widest point (posterior to eyes) 0.55 mm. Margins broadly and smoothly rounded from eyes to base (Figs 1, 18). Margins narrowing anterior to eyes before broadening slightly to clypeus. Setae sparse on vertex and becoming longer and denser towards clypeus. Anterolaterally-shifted vertexal fovea concealed in postantennal notches (region indicated in Fig. 2) by several long, apically-directed setae (Fig. 5). Eyes (Fig. 2) large with ~105 ommatidia, broadly crescent-shaped with shallow ocular canthi at posterior margin. Antennae received by triangular frontolateral excavations with carinate edges (Fig. 2). Antennal (Fig. 4) length 1.18 mm, with scape weakly transverse in dorsal view, pedicel slightly narrower and subquadrate. Antennomeres III–V subequal in width, slightly narrower and shorter than pedical, with segments becoming progressively longer apically; VI and VII transverse and subequal in length; VII wider than VI and approaching width of segment VIII. Antennomeres VIII–X with carinate apical and basal margins, roughly obconical and equal in width. Antennomere VIII slightly longer than preceding three segments, 2/3 longer than wide; antennomeres IX and X 0.7 × length of VIII; XI longest, 1.8 × length of VIII, with carinate basal margin, widest in apical half before tapering to apex. Antennomeres densely covered with apically- directed setae. Apical pseudosegment of maxillary palpus continuous with external face of palpomere IV and pointing slightly mesially.

Thorax: Pronotum (Fig. 6) length 0.68 mm, width 0.77 mm at widest point. Disc region sparsely setiferous. Lateral margins behind antebasal sulcus with several long, laterally-projecting setae. Prosternum with medial region in front of procoxae with long setae covering setiferous lateral procoxal fovea. Episternal areas with moderately dense, shorter setae orientated somewhat dorsally. Short lateral prosternal carinae extending briefly from sides of procoxal cavities. Mesoventral plate moderately setiferous, meso-epiventral regions largely glabrous. Metasternum with sparse, dorsoapically-pointing aciculate setae.

Abdomen: Dorsal abdominal length (with segments contracted) 0.57 mm. Tergite lengths: IV= 0.32 mm, V = 0.12 mm, VI = 0.10 mm. Apical margin of sternite IV with male-specific medially positioned small, round tubercle covered in small setae. Male tergite VIII (Fig. 11) with basal margin of sclerite weakly convex; with uniform moderately dense distribution of long setae. Sternite VIII (Fig. 12) with basal margin of sclerite strongly convex; mediobasal region with sparse, short setae becoming much denser towards apical margin; lateral areas of sternite with much longer setae of moderate density. Apical margin of sternite VIII medially depressed to receive corresponding apex of tergite VIII.

Elytra and flight wings: Elytra with scattered, short setae. Elytral length along suture 0.87 mm; width at widest point 0.5 mm. Full flight wings present.

Legs: Femora brownish-red, slightly lighter than body; tibiae and tarsi lighter than femora, yellowish (Fig. 1). Tarsi of increasing relative length: protarsi 0.5 × protibial length; mesotarsi 0.6 × protibial length; metatarsi 0.7 × metatibial length. Protarsomeres II 1.7 × tarsomere III length (Fig. 8). Mesotarsomeres II 1.8 × tarsomere III length. Metatarsomeres II especially long (Fig. 9), 2.3 × tarsomere III length. All tarsal claws with inner spine present on ventral face (Fig. 10). Pro- and mesotarsi with additional spines on ventral side of tarsomeres II and III (Fig. 8).

Aedeagus: Length 0.43 mm, width 0.27 mm at widest point (Fig. 13). Asymmetric, dorsoventrally relatively flattened, with large spherical and very weakly sclerotized basal bulb. Lacking obvious remnants of parameres. Complex, more heavily sclerotized medioapical piece with “hooked” apophysis extending apically from right side of basal bulb.

Sexual dimorphism.

Female dimensions similar to male. Males with large crescent shaped eyes (Fig. 16); female eyes very small and approximately oval, consisting of ~12 ommatidia (Fig. 17). Vertex of female head (Fig. 19) broader at base than that of male (Fig. 18). Antennal club ( VIII–XI) twice as long as preceding segments combined in male (Fig. 18), only 1/3 as long as preceding segments combined in female (Fig. 19). Medial sexual patch on sternite IV absent in female, and flight wings lacking. Female tergite VIII (Fig. 14) with basal margin of sclerites shallowly concave; with moderate density of long setae and two pairs of much longer setae. Female sternite VIII (Fig. 15) with basal margin of sclerite weakly convex; covered in moderate density of short setae and several pairs of much longer setae. Apex with internally-projecting cuticular protuberance.

Etymology.

The type species of Morphogenia is named in honour of Dr. Gary Struhl, developmental biologist, whose Drosophila studies have yielded great insights into the genetic control of animal development.

Biology.

Morphogenia was collected from rainforest litter-the typical habitat of jubines. Like other pselaphines, jubines are most likely predators of soil microarthropods. The spines on the ventral face of the pro- and mesotarsi of Morphogenia struhli (Fig. 8) may serve a raptorial function. Prior to photography, a filament protruding from the mouthparts of one female paratype was removed. A subsequent survey of jubine specimens in a range of genera have revealed similar filaments, which appear to be dried, threadlike residues of glutinous secretions from the enlarged maxillary cardos that are characteristic of the tribe. Such structures suggest the evolution of a novel mode of feeding or prey capture in Jubini (J. Parker & C. Carlton unpublished observations).