Myrmeconycha Konstantinov and Tishechkin, 2017

Konstantinov, A. S. & Tishechkin, A. K., 2017, Myrmeconycha new genus: the first myrmecophilous flea beetle (Coleoptera: Chrysomelidae: Galerucinae: Alticini), Insecta Mundi 2017 (525), pp. 1-13 : 2-3

Myrmeconycha Konstantinov and Tishechkin , new genus

( Fig. 1 – 42 )

Description. Body length 3.45 – 4.27 mm, width 1.72 – 2.18 mm. Body light ochre to light orange in color with or without a dark pronotum and head. In some species the middle antennomeres are lighter than rest. Head and prothorax often covered with whitish waxy secretion.

Head without midcranial and frontal sutures. Head surface uneven, covered with bumps and deep pits between them, which obscures observations of head sulci and sutures. Orbital and supraorbital sulci indistinguishable. Supracallinal sulcus thin and shallow. Supraantennal sulcus well developed. Midfrontal sulcus thin and shallow, but distinct. Suprafrontal sulcus well developed. Frontolateral sulcus well developed. Antennal callus long, trapezoidal, slightly entering interantennal space. Surface of antennal callus even, lacking bumps and depression of vertex surface, situated much above surface of vertex and orbit. Frontal ridge and vertex separated by antennal calli. Ratio of width of frontal ridge to width of antennal socket (including surrounding ridges) 0.58 – 0.67. Frontal ridge long, in lateral view almost straight. Area below antennal socket deeply concave. Orbit from normally wide to narrow, narrower than transverse diameter of antennal socket. Ratio of distance between eyes above antennal sockets to transverse diameter of eye in frontal view 3.06 – 3.15. Sides of head below eyes long, slightly converging ventrally. Labrum flat, with 2 or 3 pairs of long setae; anterior margin complete, without indentation on upper surface. Apical maxillary palpomere conical. Preapical maxillary palpomere wider than apical palpomere. Antennal sockets situated below middle of eye. Antenna filiform, with 11 antennomeres. Middle antennomeres slightly flattened dorsoventrally, with groups of pits apically. Antenna not reaching beyond middle of elytron.

Pronotum wider than long, widest at corners of anterolateral callosities, with nearly straight sides diverging anteriorly. Lateral margin covered with small denticles. Lateral margin not explanate. Anterolateral callosity relatively long, straight, slanted toward lateral margin. Pronotal disc with six cells separated from each other by tall ridges. Posterolateral callosity short, barely protruding beyond lateral margin. Pronotum covered with bumps and small ridges (but often concealed by wax). Base with short lobe in middle. Procoxal cavities open. Intercoxal prosternal process long, parallel-sided, extending beyond procoxae, lateral sides straight, posterior end rounded.

Scutellum long, wide at apex. Elytron with four sharp longitudinal ridges. Elytral punctation confused. Elytra at base wider than base of pronotum. Humeral calli well developed. Basal calli present, separated from elytral disc. Epipleura slightly oblique outwardly, gradually narrowing from base to apex, reaching end of elytron side. Mesosternum short, with deep depression in middle. Metasternum short, with longitudinal ridge in middle, anteriorly without elevated projection and not projecting forward covering mesosternum.

Abdominal ventrite 1 free. Abdominal ventrites about equally long. First abdominal ventrite between coxae without longitudinal ridges, with apex acute. Last visible tergite without longitudinal groove in middle.

Pro- and mesotibiae slightly canaliculate dorsally. Pro- and mesotibial spurs absent. Metatibia slender, slightly curved in dorsal view. Metatibia in cross section at its middle more or less round. Dorsal surface flat. Bristles present on lateral and mesal sides of metatibiae. Metatarsomere 1 attached to metatibial apex. Apical spur of metatibia simple, situated at middle, directed medially. Metatarsomere 1 narrow in females, wider in males, with flat ventral surface, shorter than rest of metarsomeres together. Claws appendiculate. Wings with full set of veins characteristic for flea beetles.

Median lobe of aedeagus in cross section somewhat flat, without impressions near apex on ventral surface, abruptly curved at apex in lateral view. Apex with a knob.

Spermatheca with oval receptacle, much smaller than pump. Pump and receptacle separated by distinct border. Gland attached to receptacle. Spermathecal duct not observed. Vaginal palpi membranous, short, poorly preserved on slides. Tignum long, with wide and relatively long explanation anteriorly, posterior sclerotization narrow.

Etymology. The genus is named for its myrmecophilous habits and relationships with flea beetles of the subtribe Disonychina . The name is feminine.

Figures

Figures 1–11. Myrmeconycha erwini. 1, 2, 3) Habitus, dorsal, lateral and ventral views. 4) Head, frontal view. 5) Hind tarsus, lateral view. 6) Ventral view. 7) Antenna. 8) Apex of 8th antennomere. 9) Hind tarsus dorsolateral view. 10) Female abdomen. 11) Tignum.

Figures 12–19. Myrmeconycha gordoni. 12, 13, 14) Habitus, dorsal, lateral and ventral views. 15) Head, frontal view. 16) Pronotum. 17) Hind leg. 18) Female abdomen. 19) Spermatheca.