Mordellistena luteipalpis Schilsky, 1895

Zemoglyadchuk, Aleksei & Buialska, Nataliia, 2020, Description of the larvae of three species of the genus Mordellistena (Coleoptera: Mordellidae) with notes on their ecology, Zootaxa 4743 (3), pp. 371-381 : 372

Mordellistena luteipalpis Schilsky, 1895

Material examined: Belarus: Gomel Region, the city of Gomel, 52°42’N 31°03’E, floodplain of the Sozh River , meadow, in the stems of Galium verum , 09.xii.2017, 4 larvae ; same locality, 24.xii.2017 , 1 larva. Ukraine: Chernihiv Region, near the city of Chernihiv, 51°48’N 31°31’E, floodplain of the Desna River , meadow, in the stems of Galium verum , 13.i.2018, 4 larvae ; same locality, 17.iv.2018 , 1 larva; same locality, 03.v.2018, 5 larvae ; same locality, 17.iv.2018 , 1 larva; same locality, 03.v.2019, 4 larvae .

Body shape: Body cylindrical, slender, gradually narrowed posteriorly, 5.1–6.1× as long as wide ( Figs 1–2 ).

Coloration: Body bright yellow, head brownish with lighter pattern along rows of setae.

Size: Body length: 4.8–5.5 mm.

Head: Head slightly flattened, 1.1× as long as wide; 1.5× narrower than prothorax; with two tightly clustered stemmata beneath single small cuticular lens on each side; epistome weakly sclerotized in middle; primary head setae long; secondary head setae numerous; head contour from front slightly oval ( Fig. 7 ). Antennae 1-segmented, each with narrow sensorium, three equally long sensilla chaetica and four small sensilla basiconica ( Fig. 8 ). Clypeus smooth. Labrum evenly sclerotized, 1.1× as wide as long, apical margin straight, with two long median setae, two long lateral setae, four short lateral setae placed closer to anterior margin and four short setae on border with epipharynx; without microtrichia in lateral portions. Mandibles each with weakly sclerotized triangular area and 4–5 setae in lateral portions; subapical tooth well-defined, sharp ( Fig. 9 ). Maxillolabial complex sharply narrowed to base in proximal portion ( Fig. 10 ); cardo sclerotized, with one fairly long seta; stipes large, with numerous setae, weakly sclerotized, strongly curved on inner margin; palpifer weakly sclerotized; maxillary palp 2-segmented, basal palpomere 1.1–1.3× as wide as long, with two setae, apical palpomere 1.4–1.5× as long as wide, 1.1–1.4× shorter than basal palpomere, with one seta; postmentum with two long setae; prementum with two long setae in middle and sometimes with 2–3 short additional setae; palpiger weakly sclerotized, with one seta; ligula widely rounded, with two fairly long setae, almost without spines; labial palp 1-segmented, 1.8–2.3× as long as wide, with two long sensilla basiconica at apex ( Fig. 11 ).

Thorax: Prothoracic tergum trapezoidal, with numerous setae, without sclerotized asperities and transversal sulcus; mesothoracic and metathoracic terga with one long seta and numerous shorter setae in lateral portions. Mesothoracic spiracles round.

Legs: Relatively large, rather slender, with numerous setae; apex of distal segment without setae.

Abdomen: Abdominal segments with one long seta and numerous short setae laterally; dorsal protuberances on abdominal segments I–VI well-defined, strongly prominent; lateral protuberances absent; abdominal segment IX relatively short, conical, rounded at apex, covered by numerous long setae, without sclerotized teeth; preanal tubercles large, each with 29–37 setae. Apical processes spike-like, small, weakly sclerotized, not fused, each with one short seta in middle ( Figs 12–14 ). Abdominal spiracles round.

Figures

FIGURES 1–6. Habitus of the larvae. 1, 2: Mordellistena luteipalpis Schilsky, 1895 (1: dorsal view; 2: lateral view); 3, 4: Mordellistena koelleri Ermisch, 1956 (3: dorsal view; 4: lateral view); 5, 6: Mordellistena brevicauda (Bohemann, 1849) (5: dorsal view; 6: lateral view). Scale bars: 1 mm.

FIGURES 7–14. Details of the larva of Mordellistena luteipalpis Schilsky, 1895. 7: head; 8: antenna; 9: mandible, ventral view; 10: maxillolabial complex; 11: labial palp; 12: apical process, lateral view; 13: apical processes, dorsal view; 14: apical processes, posterior view.