Myrmecoagria Eldredge, 2022

Eldredge, K. Taro, 2022, A new myrmecophilous genus of Falagriini from Colorado, USA (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 5165 (4), pp. 575-590 : 577-580

Myrmecoagria Eldredge , new genus

Description. Body ( Figs. 1–2 ) approximately 3 mm in length and ground color light reddish brown overall. Body without microsculpture asides from inconspicuous setal pores. Overall covered in short yellow microsetae with abdominal microsetae slightly longer, particularly at apicies. Macrosetae present on abdominal segments. Head: Head ( Fig. 2 ) reddish brown and transverse; broadest slightly anterior of temples; broadly triangular in form; temples broadly rounded; vertex slightly broadly impressed;; neck short and relatively broad (~ 1/3 HW). Eyes small (~ 1/4 HL). Antennae gradually clavate and slightly longer than head and pronotum combined. Labrum ( Fig. 6 ) transverse with lateral margins broadly arcuate; median lobe broad, slightly produced and membranous; epipharyngial surface with porous medial pore field and variously sculptured border-, mesolateral-, marginal-, basal-, and basolateral regions, with a sculpture gradation, becoming less acute, less produced and generally smaller from the inner-apical portion posteriorly and marginally. Mandibles ( Fig. 7 ) overall broadly triangular. Maxilla ( Fig. 8 ) galea overall short and shorter than lacinia, distal lobe modest and compact, pallisade trichae relatively prominant; lacinia blunt with moderately produced membranous medial lobe, S1 with a clustered row of teeth, and S2 with two distinct wellspaced isolated spines; palpi relatively short and stout, palpomere III broadly clavate, palpomere IV conical in form and distinctly and uniformly narrowing apically. Labial complex ( Fig. 9 ) mentum transverse; prementum transverse with broad lateral apodemes; palpi short and stout, palpomere I longer than II and III combined, palpomere II small and transverse; glossa longer than wide and divided at apical third. Prothorax: Pronotum ( Fig. 2 ) reddish brown and transverse and generally sub-rectangular in form; disc with a faint medial longitudinal sulcus that fades distally; anterior corners deflected ventrally, hypomera anteriorly prominent in lateral view, gradually becoming strongly inflexed posteriorly; marginal bead extremely faint. Mesothoracic peritreme sclerites relatively small, narrowly produced laterally and not contiguous at midline or with pronotal hypomera. Meso-metathoracic complex: Elytra yellowish and transverse. Scutellum simple and triangular in form. Mesosternal process acute, angulate and extending to middle, slightly ventral of metasternal process; metasternal process acute and roundly produced, extending shy of middle, smoothly sloping off laterally into acetabulae; isthmus narrow; marginal bead absent. Abdomen overall more or less parallel-sided and slightly narrowing distally; length ~ 1.5 mm long; base reddish brown with apex blackish. Tergite VIII apicies without a row of fimbriate setae or a comb of minute denticles; broadly medially produced in females. Sternite VIII without major modifications; narrowly medially produced in males. Spermatheca ( Fig. 10 ) tightly S-shaped; apex simple and bluntly produced; cone weakly produced; reticulate sculpturing prominent. Aedeagus: Median lobe ( Figs. 15–16 ) with basal capsule evenly rounded and apical lobe produced and more or less evenly narrowing apically; distal apodeme present and complete; longitudinal bands paired with a ribbed texture; internal sac adorned by a pair of numerous rows of sclerotized teeth present lateral of a simple penniform copulatory piece. Paramere ( Fig. 17 ) deep; paramerite broadly V-shaped; condylite broadly elongate; apical lobe short and squarely produced; condylite and paramerite distinctly separated, condylite distally produced beyond articulation with paramerite, condylite and paramerite vellums clearly separated and only connected by a thin membrane.

Diagnosis. Myrmecoagria can be distinguished from all other North American Falagriini genera by the following combination of characters: (1) head and pronotum markedly transverse; (2) mesothoracic peritreme sclerites relatively small, narrowly produced laterally and not contiguous at midline or with pronotal hypomera; (3) tergite VIII apical margin without a comb of denticles.

Etymology. Derived from the Greek word myrmecos to mean ant and - agria from Falagria , the type genus for Falagriini . Gender is feminine.

Type species. Myrmecoagria hoebekei , new species

Figures

FIGURE 6. Labral complex, ventral, paratype female.

FIGURE 17. Paramere, internal, holotype.

FIGURES 1–5. (1) Habitus of Myrmecoagria hoebekei, male holotype. (2) Head and pronotum of Myrmecoagria hoebekei, male holotype. (3) Paratype labels, female. (4) Holotype labels, male. (5) Habitus of host pinned with paratype female.

FIGURES 7–8. (7) Right mandible, dorsal, paratype female. (8) Right maxilla, ventral, paratype female.

FIGURES 9–10. (9) Labial complex, ventral, paratype female. (10) Spermatheca, paratype female.

FIGURES 15–16. (15) Median lobe, lateral, holotype. (16) Median lobe, parameral, holotype.