Microlia cayaponia Zilberman & Pires-Silva, 2023

Zilberman, Bruno, Cardoso, Renan Kobal De Oliveira Alves, Pires-Silva, Carlos M. & Santos, Isabel Alves Dos, 2023, Microlia cayaponia, a new pollen-feeder species from Brazil (Staphylinidae: Aleocharinae: Hoplandriini) and its potential competition in pollinator activity in Cayaponia plants (Cucurbitaceae), Zootaxa 5264 (3), pp. 405-417 : 407-412

Microlia cayaponia Zilberman & Pires-Silva sp. nov.

Female — Figs. 3–4 , Male— Figs. 1–2 , 34

Body small, slightly tapering through the apex, total length 1.5 mm in average for males and females, some specimens can reach higher lengths, but never surpassing 2 mm. Sclerotized parts mostly dark brown, except for legs and five or six basal antennomeres and mouthparts which are lighter, yellowish brown; head, scutellum, pronotum, and elytra densely covered with short hair; abdomen bearing longer and sparser bristles.

Head transverse, vertex densely covered with bristles, except the anterior medial region which bristles are scarcer ( Figs. 2 , 4 , 29–30 ). Mentum-submentum distinct, with mentum bearing three main bristles on each anterior angle (u, v, w): a medium-sized bristle (u) sided with a short one (v), and both in front of the longer bristle (w); medialinternal region with a short to medium bristle, and posterior region with a short bristle on lateral margin ( Figs. 30, 31 ). Antennae with 11 antennomeres; scape elongate, slightly longer than antennomere 2; antennomere 3 subconical, antennomere 4 subquadrate, antennomeres 5–10 transverse, gradually widening through apex; antennomere 11 suboval as long as antennomeres 8–10 combined, bearing two sensilla ( Figs. 1–4 , 26–28 ). Mouthparts. Labrum transverse, more than twice as wide as long, with distal median region emarginate; eight main bristles present on each side: three on median region, and five on distal region ( Fig. 9 ). Mandibles asymmetrical, right mandible with a medial tooth and crenulate on the cutting edge; prostheca well developed ( Figs. 5–7 , 32, 33 ). Maxilla with lacina subquadrate with a marginal row of midsized bristles; galea slender, with apex densely covered with short bristles; maxillary palpi setose and four palpomeres and pseudoarticle ( Figs. 10 , 30 ). Labium. Prementum with three palpomeres and pseudoarticle; ligula divided into two lobes ( Fig. 8 , 30 ).

Thorax. Prothorax. Pronotum covered with short hair, transverse, about 1.4 wider than long, anterior margin straight, round lateral margin gradually converging to a wider and convex posterior region ( Figs. 2 , 4 , 34 ). Scutellum semi-fusiform, covered with short hair. Mesothorax without carena, with mesocoxal cavities marginated. Metathorax with metaventral process less developed. Elytra more than 1.6 longer than wide, covered with short hair, ( Figs. 2 , 4 , 34 ). Wings developed. Legs well-developed, tarsal formula 4-5-5.

Abdomen with rows of long bristles on distal region of tergites and sternites II–VII ( Figs. 1–4 , 30 ); tergite I narrow and reduced, attached to metanotum, with medial region slightly projected backward. Tergite VII with apex densely covered with rows of bristles, being the most apical forming a conspicuous band with bristles one closely next to the other ( Figs. 1–4 , 34, 37, 38 ). Tergite VIII with four main pairs of bristles: two in a medial row, two in distal region ( Figs. 11–12 ), with a midsize additional bristle often present in some specimens, next to the inner main bristle of distal row. Sternite VIII with four pairs of lateral bristles and two longitudinal median pairs of three midsize bristles in male ( Figs. 13 , 35 ), three pairs of lateral bristles and two longitudinal medial pairs of two long bristles in females ( Fig. 14 , 36 ); distal margin sinuous in male; evenly in female. Tergite IX with three bristles and short apodemes in female ( Fig. 17 ), and five bristles and long apodemes in male ( Figs. 15 , 41 ). Tergite X with four pairs of long bristles on lateral margin and multiple short rows of midsize bristles on medial region; apex evenly round in male, slightly acute in female ( Figs. 18, 19 , 42 ). Sternite IX as a unique elongate piece in male, with at least five long bristles amid shorter ones at apex ( Figs. 16 , 39, 40 ); divided into two smaller pieces attached each to the sides of tergites IX in female ( Fig. 17 ). Aedeagus with lateral lobes curved towards and passing the apex of the median lobe ( Figures 20 , 43 ); ventral apex of median lobe short, overall lateral shape as in Figures 21 and 44 , lateral lobes as in Figures 22 , 47 and 49 ; lateral lobes with a shorter and three long bristles on apex ( Fig. 24 , 48, 50 ) and a sponge-like structure towards apex ( Figs. 23 , 47 ); apex of median lobe with multiple dentate structures, varying from unique, two or three acute apices ( Figs. 45, 46 ). Spermatheca with capsule flattened at apex, and stem with three to four regular coils; accessory sclerite absent ( Fig. 25 ).

Etymology. The specific name refers to the host plant Cayaponia, with which the beetles were found associated. Noun in apposition.

Type material. Holotype, male: BRAZIL. São Paulo: Campos do Jordão, 15.II.2020, with Cayaponia cabocla, Kobal col., pinned ( MZSP 21278 ) . Paratypes same data as holotype, 142 specimens, most pinned and 3 (2 males and 1 female) on slides ( MZSP 21276 , 21277 , 21279–21418 ), 2 males and 2 females separated to be sent to the Field Museum of Natural History .

Additional material. Many specimens in alcohol, same data as the type series, some specimens cleared in a separated vial, 3 males and 3 females used for scanning electron microscopy, and 15 specimens in a separated vial to be sent to Chungnam National University ( CNU) ( MZSP 21421 ) .

Remarks. Microlia cayaponia Zilberman & Pires-Silva sp. nov. individuals are similar in overall appearance to M. azteca (Casey) and with darker specimens of M. meticola (Casey) . It can be distinguished from them by the spermatheca’s flattened capsule (somewhat rounded in previous species) and three to four regular coils in stem (multiple regular coils in M. meticola , and multiple irregular coils in M. azteca ) ( Gusarov 2002), and from the shape of ventral apex of aedeagus which is much shorter when compared to both previous species. The four to seven basal antennomeres being lighter than the apical ones seems to be characteristic of species recorded in North, Central, and South America, not shared with the supposedly myrmecophilous species from Australia, having the antenna at least mostly uniformly colored.

The sexual dimorphism in the genus, especially concerning the chaetotaxy of the female sternite VIII, based on our study and from the illustrations in Gusarov (2002) and Bortoluzzi et al. (2016), is highly consistent across the species within the genus. All females have two pairs of two long main bristles longitudinally arranged in medial region, and three to four long bristles on each lateral margin, while males have more densely, shorter and more variable distributed bristles, even though two longitudinal rows of three midsize bristles in medial region are conspicuously noted in Microlia cayaponia sp nov. The only exceptions are probably the males of M. amici Bortoluzzi & Caron and M. machadoi Bortoluzzi & Caron (both in Bortoluzzi et al. 2016) which bristles look much scarcer, and the female of M. machadoi which has only a pair of long bristles in medial region. The sternite of the male of M. cayaponia sp. nov has the chaetotaxy similar to M. tetramera Gusarov , and the female sternite has three bristles on lateral margin as in M. silicae (Erichson) , M. pentamera Gusarov , M. tetramera and M. amici .

Another series of individuals was spotted on flowers of Cayaponia pilosa , however, those specimens were not studied in laboratory; thus the relationship of M. cayaponia sp. nov. with Cayaponia pilosa remains hypothetical.

Microlia cayaponia sp. nov. is the third species of the genus recorded from Brazil; the other two, M. amici and M. machadoi , are easily distinguished by the much lighter pronotum.

Distribution. This new species is known only from the type locality; the Campos do Jordão State Park, located in the municipality of Campos do Jordão, a mountain region covered by Atlantic forest.

Figures

FIGURES 3–4. Microlia cayaponia sp. nov., paratype, female. 3, lateral habitus; 4, dorsal habitus. About 1.6 mm, from tip of the head to abdominal apex.

FIGURES 1–2. Microlia cayaponia sp. nov., holotype, male. 1, lateral habitus; 2, dorsal habitus. About 1.7 mm, from tip of the head to abdominal apex.

FIGURES 34–42. Microlia cayaponia sp. nov., 34, dorsal habitus (male); 35, sternite VIII (male, rows of three bristles colored purple); 36, sternite VIII (female, rows of two bristles colored purple); 37, tergite VII; 38, tergite VII, detail of bristles at apical margin; 39, sternite IX (male); 40, sternite IX, apex (male); 41, tergite IX (male, one long bristle broken); 42, tergite X (male). Scale bars: 34, 0.1 mm; 35–37, 0.01 mm; 38, 0.001 mm; 39, 41–42, 0.02 mm; 40, 0.003.

FIGURES 29–33. Microlia cayaponia sp. nov., head. 29, dorsal; 30, ventral; 31, mentum-submentum; 32, right mandible, front-dorsal view; 33, right mandible, apex, with medial tooth colored purple. Scale bars: 29, 0.03 mm; 30, 0.02 mm; 31–32, 0.01 mm; 32, 0.003 mm.

FIGURES 26–28. Microlia cayaponia sp. nov., antenna. 26, whole antenna; 27, antennomere 11; 28, detail of a sensillum of antennomere 11. Scale bars: 26, 27, 0.01 mm; 28, 0.001 mm.

FIGURES 5–25. Microlia cayaponia sp. nov., paratypes, 5, left mandible (dorsal), 6, left mandible (ventral), 7, mandible, ventrolateral view, with arrow indicating the medial tooth; 8, prementum; 9, labrum; 10, maxilla; tergite VIII (11, up, male;12, bottom, female); sternite VIII (13, up, male;14, bottom, female); 15, sternite X (male); 16, sternite IX (male); 17, sternites X and IX (female, arrow indicating SIX); 18, tergite X (male); 19, tergite X, female; 20, aedeagus; 21, medium lobe of aedeagus; 22, lateral lobe of aedeagus; 23, sponge-like structure of lateral lobe of aedeagus; 24, apex of lateral lobe of aedeagus; 25, spermatheca. Scale bars: 5–7, 11–25, 0.005 mm; 8, 0.0006 mm; 9, 0.002 mm; 10, 0.01 mm.

FIGURES 43–50. Microlia cayaponia sp. nov., aedeagus. 43, whole aedeagus, ventral; 44, median lobe, lateral; 45, apex of median lobe, lateral; 46, apex of median lobe, detail of dentate region; 47, paramere, internal view; 48, apex of paramere; 49, paramere, outer view; 50, apex of paramere. Scale bars: 43–44, 47, 49, 0.02 mm; 45, 50 0.01 mm; 46, 0.002 mm; 48, 0.003 mm.