Ikaros, Chatzimanolis & Brunke, 2021

Chatzimanolis, Stylianos & Brunke, Adam J., 2021, A new apterous rove beetle genus (Coleoptera: Staphylinidae) from the Northern Andes with an assessment of its phylogenetic position, European Journal of Taxonomy 744, pp. 67-82 : 71-73

Ikaros gen. nov.

urn:lsid:zoobank.org:act:547CE969-6222-48B6-BA7C-AAE86C5C4015

Figs 2–6

Type species

Ikaros paramo gen. et sp. nov., here designated.

Diagnosis

Ikaros gen. nov. belongs in Xanthopygina based on the following two synapomorphies present: inferior marginal line of the pronotal hypomeron continues as a separate entity beyond anterior pronotal angles and curves around them, and hypostomal cavity moderately delimited (i.e., cavity surface without microsculpture or punctation different from the rest of nearby head surface). The genus can easily be distinguished from all other Xanthopygina based on the reduced elytra (exposing the 2 nd tergum), absence of hind wings and the shape of the abdomen: constricted anteriorly and expanded posteriorly.

Etymology

The word Ikaros is an alternate spelling of the word Icarus, the son of Daedalus who (in the Greek mythology) constructed the Labyrinth. Icarus and Daedalus escaped the Labyrinth by flying with wings made of feathers and glued by wax. However, Icarus flew too close to the sun and the wax melted. The name is rather appropriate for this genus considering these are species found in high altitudes that have lost their wings. The name is masculine.

Description

HABITUS ( Fig. 2 ). Body medium-sized, forebody 5.2–7.1 mm long, without long bristle-like setae.

COLORATION. Brown to reddish-brown.

HEAD. Shape rectangular; head length in comparison to pronotum shorter to subequal. Eye size small, less than ½ length of head. Postclypeus, in comparison to frons, not deflexed; anterior margin slightly emarginate. Middle of epicranium impunctate but with microsculpture. Postmandibular ridge laterally; with deep punctures demarcating raised postmandibular ridge dorsolaterally absent. Gular sutures not joined before neck, extended close to each other at base of head capsule. Nuchal ridge incomplete dorsally. Neck disc with dense, moderately coarse punctures. Antennae with relative width of antennomere 1 same width or slightly wider than antennomere 2. Antennomeres 1–5 longer than wide; 5–10 subquadrate. Antennomere 3, 2.5 times as long as wide or less; antennomere 4 with tomentose pubescence; antennomeres 4–10 cylindrical in shape; antennomeres 5–10 without club; antennomeres 8–10 symmetrical, quadrate to elongate; antennomere 6 with curved, distinctly longer and thicker subapical setae than other macrosetae, forming circlet; antennomere 11 in males slightly longer than 10. Mouthparts with labrum having broadly U-shaped emargination, lobes strongly separated. Mandibles with relative length typical (i.e., closed mandible not extending beyond lateral margin of head); without asymmetrical torsion. Mandible in dorsal view curved from apical half; in lateral aspect: straight; left and right mandible each with one tooth. Maxilla with galea much shorter than palpus; maxillary palpus with palpomere 3 distinctly shorter than palpomere 2; palpomere 4 distinctly longer than palpomere 3; palpomere 4 not dilated. Labial palpus with palpomere 3 widest apically, subparallel-sided (widest before apex in I. polygonos gen. et sp. nov.); palpomere 3 without long dense setae on entire lateral sides. Ligula small, entire. Mentum with alpha seta present; hypostomal cavity present; moderately delimited.

PRONOTUM. With shape of lateral margins in dorsal view posteriad of midpoint straight to sinuate; anterior angles in dorsal view not strongly acuminate and produced laterad. Pronotum near anterolateral angles without raised impunctate spots; anterolateral corners with punctation; disc of pronotum with punctation beyond midlength (but punctation not continuing beyond midlength in I. apteros gen. et sp. nov.); punctation varies but microsculpture present; without coarse punctures impressed in flange at posterior angle of pronotum. Hypomeron with superior marginal line continuous to anterior margin; superior marginal line without distinct deflection under anterior angles in ventral view; inferior marginal line of hypomeron continued as a separate entity beyond anterior pronotal angles and curving around them. Postcoxal process absent. Basisternum slightly longer than furcasternum; basisternum with pair of macrosetae, situated far from anterior margin of prosternum.

ELYTRA. Reduced, exposing tergum 2. Hind wings absent. Elytra setae not reduced, easily seen at low magnification; without patches of white setae. Elytra without contiguous polygon-shaped meshed microsculpture. Mesoscutellum with dense cluster of punctures medially. Mesoventrite without median carina; mesoventral process broadly triangular; process extended distally to distance 2/5 between mesocoxae. Metaventrite with small punctures; metaventral process small, rounded, triangular extended to beginning of metacoxae.

LEGS. With tarsal segmentation 5-5-5; profemora without lateroventral apical spines; protarsi with modified pale (adhesive) setae ventrally; tarsomeres 1–4 of protarsi dorsoventrally flattened. Mesocoxae moderately separated, intercoxal area distinctly recessed compared to mesoventrital process only. Metacoxae without coxal shield; metatibia without thick and long apical spurs but smaller spurs (and spines) present; tarsomeres 3–5 of metatarsi with chaetotaxy, developed only at margins of dorsal surface; dorsal surface of tarsomeres glabrous along midline. Pretarsal claws with empodial setae.

ABDOMEN. With lateral sides in dorsal view constricted anteriorly and expanded posteriorly; with protergal glands having well-developed acetabula. Anterior basal transverse carina on terga 3 and 4 without pair of accessory ridges; tergum 3 without posterior basal transverse carina or curved (arched-like) on disc (except arched-like carina present on I. polygonos gen. et sp. nov. on terga 3–5). Tergum 5 without pair of accessory ridges on anterior basal transverse carina; centre of tergum 5 punctate; posterior half of tergum 5 in lateral view not appearing bulging. Sternum 3 with straight to arcuate basal transverse carina medially; basal transverse carina laterally not sinuate. Sternum 4 without basal transverse carina medially. Sternum 5 with dense, meshed microsculpture anterolaterally, appearing different in texture to posterior portion. Sternum 7 with sparse (punctures separated by more than two puncture width) punctation laterally.

MALE GENITALIA. With secondary sexual structures (medial emargination) on sterna 7 and 8; without porose structure on sternum 7. Aedeagus as in Figs 3–5 ; with long median lobe and single paramere;

paramere with sensory peg setae; median lobe with single subapical tooth; without apical tooth, carina or paired apex.

FEMALE GENITALIA. Without secondary sexual structures. Spermathecae not sclerotized.

Habitat

Ikaros paramo gen. et sp. nov. was collected in dry to sub-humid paramo, an ecosystem characterized as high altitude, tropical, montane, and above the tree line. Ikaros polygonos gen. et sp. nov. was collected from an area with interspersed páramo and shrubby/treed patches (R. Anderson pers. com.), and judging from the locality and elevation, Ikaros apteros gen. et sp. nov. appears to live in a similar habitat.

Figures

Fig. 2. Habitus photographs of species of Ikaros gen. nov. A. I. apteros gen. et sp. nov. Holotype, ♂ (SDEI). B. I. paramo gen. et sp. nov. Paratype, ♂ (barcode: SM05500251, UTCI). C. I. polygonos gen. et sp. nov. Holotype, ♂ (barcode: SM0114364, MIZA). Scale bars = 5 mm.

Fig. 3.Aedeagus ofIkaros apteros gen. et sp. nov.A. Dorsal view.B. Lateral view.C. Detail of paramere, ventral view.

Fig. 4. Aedeagus ofIkaros paramo gen. et sp. nov.A. Dorsal view.B. Lateral view.C. Detail of paramere, ventral view.

Fig. 5. Aedeagus of Ikaros polygonos gen. et sp. nov. A. Dorsal view. B. Lateral view. C. Detail of paramere, ventral view.

Fig. 6. Distribution map of Ikaros apteros gen. et sp. nov. (square), I. paramo gen. et sp. nov. (circle) and I. polygonos gen. et sp. nov. (triangle).