Mordellistena brevicauda (Bohemann, 1849)

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 : 373-374

Mordellistena brevicauda (Bohemann, 1849)

Material examined: Ukraine: Chernihiv Region, near the city of Chernihiv, 51°48’N 31°31’E, floodplain of the Desna River , meadow, in the rhizomes of Galium verum , 16.vii.2018 , 1 larva; same locality, 24.vii.2018, 2 larvae ; same locality, 29.vii.2018 , 1 larva; same locality, 30.vii.2018, 7 larvae ; same locality, 26.viii.2018, 4 larvae ; 05.v.2019, 5 larvae .

Body shape: Body cylindrical, slender, more or less parallel-sided, 4.5–5.3× as long as wide ( Figs 5–6 ).

Coloration: Body white or yellowish, with brownish pattern on head along rows of setae.

Size: Body length: 6.5–8.3 mm.

Head: Head globular, 1.1× as wide as long, with two tightly clustered stemmata beneath single relatively small cuticular lens on each side; 1.3–1.5× narrower than prothorax; epistome weakly sclerotized in middle; primary head setae relatively long; secondary head setae numerous, but few above genal setae 1 and 2; head in frontal aspect roundish ( Fig. 23 ). Antennae 2-segmented, basal antennomere 1.1× as long as wide, distal antennomere with narrow sensorium, three equally long sensilla chaetica and three small sensilla basiconica; 1.8–1.9 times shorter than basal antennomere ( Fig. 24 ). Clypeus microreticulated. Labrum less sclerotized in apical one-third, 1.3× as wide as long, straight on apical margin, without microtrichia in lateral portions, with two long median setae, two long lateral setae, four short setae close to anterior margin, four short setae on border with epipharynx and 4–13 setae of various length and position. Mandibles each with weakly sclerotized triangular area and 5–6 setae in lateral portions, subapical tooth blunt ( Fig. 25 ). Maxillolabial complex gradually narrowed to base in proximal portion ( Fig. 26 ); cardo sclerotized, with one fairly long seta; stipes expanded, with numerous setae, slightly sclerotized and strongly curved on inner margin; palpifer slightly sclerotized in lateral portions; maxillary palp 2-segmented, basal palpomere with two setae, 1.1× as wide as long, distal palpomere with one seta, 1.6–1.7× as long as wide, 1.2–1.4× shorter than basal palpomere; postmentum with two long setae; prementum with 2–4 long setae in middle and 2–4 shorter setae on each lateral portion; palpiger moderately sclerotized medially, with one seta; ligula rounded, with two short setae and comparatively long spines; labial palp 2-segmented, basal palpomere 1.1–1.2× as wide as long, distal palpomere with four rather long sensilla basiconica on apex; 1.8–1.9× as long as wide, 1.1× longer than basal palpomere ( Fig. 27 ).

Thorax: Prothoracic tergum rectangular, with numerous setae, without sclerotized asperities and transversal sulcus; mesothoracic and metathoracic terga with comparatively numerous 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 setae approximately equal in length in lateral portions; dorsal protuberances on abdominal segments I–VI weakly prominent; lateral protuberances on abdominal segments I–VIII rather narrow; abdominal segment IX elongate, conical, apex elongated, narrow, with numerous teeth in apical portions, dorsal pair of teeth near apical process larger, ventral pair of teeth located on apical process; preanal tubercles small, with 24–27 setae. Apical processes fused in single strongly sclerotized, slender tube-like process, with one pair of very short setae ( Figs 28–30 ). 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 23–30. Details of the larva of Mordellistena brevicauda (Bohemann, 1849). 23: head; 24: antenna; 25: mandible, ventral view; 26: maxillolabial complex; 27: labial palp; 28: fused apical processes, lateral view; 29: fused apical processes, dorsal view; 30: fused apical processes, posterior view.