Odontomesa fulva (Kieffer)

Liu, Wenbin, Ferrington, Leonard C. & Wang, Xinhua, 2016, First record of Odontomesa Pagast from China, with description of the immature stages of O. ferringtoni Saether (Diptera, Chironomidae, Prodiamesinae), Zootaxa 4132 (1), pp. 135-142 : 136-138

Odontomesa fulva (Kieffer)

( Figs. 1–11 )

Prodiamesa fulva Kieffer, 1919: 132

Monodiamesa fulva ( Kieffer) Kieffer, 1922: 287

Prodiamesa nigripalpes Goetghebuer, 1922: 52

Prodiamesa flabellata Kieffer in Zavrel 1926: 279

Odontomesa fulva (Kieffer) , Pagast 1947: 503, 541, 587 Cryptochironomus polysetica Botnariuc & Cure, 1956: 259 Orthocladiinae gen.? 1. dospactica Dimitrov, 1963: 13 Odontomesa fulva fulva Saether, 1986a: 18

Odontomesa fulva (Kieffer) Makarchenko, 1985: 105 –106; Ashe & O' Connor 2009: 326

Diagnositic characters (following Saether 1986a): Male imagines: Inferior volsella about 1.3–1.4 times as long as length of gonostylus, and relatively narrow, about 5–6 times as long as wide; median volsella with 1–2 setae; hind leg with 2–3 sensilla chaetica. Female imagines: Gonocoxite with about 14 setae, R1 with about 15 setae, about 3 prealars. Pupal stage: five anal macrosetae, 46–58 setae in fringe of anal lobe. Larvae stage: Posterior margin of ventromental plate often straight and nearly parallel with anterior margin, basal external seta of mandible split to base or occasionally single at base.

Materials examined. 1P³, 1P♀ and 2L, China: Xinjiang Uygur Autonomous Region, Yili Valley, Turks County, 43°21’80’’N, 81°83’60’’E. viii.4.2002. H. Q. Tang.

Pharate adult. Genitalia of Male (n = 1) ( Figs. 3, 7 & 8 )

Anal point triangular, 29 µm long, 50 µm wide at base. Tergite IX with 16 setae. Laterosernite IX with 5 setae. Aedeagal lobe 37 µm long. Phallapodeme 60 µm long. Transverse sternapodeme 76 µm long. Gonocoxite 265 µm long. Superior volsella small, rounded, with microtrichia, situated at base of inferior volsella. Inferior volsella 145 µm long, 35 µm wide. Median volsella with 4 setae. Gonostylus 120 µm long. Megaseta 15 µm long.

Genitalia of Female (n = 1) ( Figs. 9–11 ).

Gonocoxite with 13 setae. Tergite IX with 20 setae. Cercus 158 µm long. Seminal capsule 78 µm long including 20 µm long neck; 50 µm wide. Notum 218 µm long.

Pupa (n = 2). Total length 5.15–5.30 mm. Exuviae brown.

Cephalothorax ( Figs. 4–5 ). Frontal setae 84–125, 102 µm long. Ocular field with two 85–110 µm long postorbitals, and 100–113 µm long vertical. Median and lateral antepronotals hard to measure. Thoracic horn 620– 640 µm long, 145–150 µm wide; 2.29–2.48 times as long as anal macrosetae. Anterior precorneal setae 131–143 µm long; median setae 50–73 µm long; posterior setae 83–93 µm long. Dorsocentrals hard to measure. Prealars 100–120 µm long.

Abdomen ( Figs. 3, 6 ). L3 on segment III split into 5 branches; on IV split into 3 branches. Distances from L3 of segment VIII to apex of caudolateral extension 170–195 µm; length of extension 140 µm. Anal lobe 495–520 µm long and 190–200 µm wide at base, with 5 subequal anal macrosetae 250–280 µm long; and 59–60 setae in fringe.

Fourth instar larva (n = 2). Total length 7.02–8.49 mm. Head capsule light brown. Head capsule length/ width: 410–420 µm/390–420 µm: 1.00–1.05.

Head. Antenna with 4 flagellomeres. Lengths of antennal segments (µm): 63; 18; 5; 3. AR 2.42. Basal antenna segment 18–20 µm wide; distance from base to ring organ is 1/3 of the length of base. Accessory blade 13–20 µm long. Premandible 75–78 µm long, with 1 apical tooth and 1 inner tooth. Mandible ( Fig. 1 ) yellow, 110–113 µm long with 1 apical tooth and 4 inner teeth. Seta interna with 20–22 setae. Pecten mandibularis brush–like. Mentum ( Fig. 2 ) dark brown, teeth unclear to be readily observed, covered by ventromental plates. Ventromental plates 85 µm wide, 13 µm long. setae submenti very well-developed. Postmentum 180–200 µm long.

Abdomen. posterior parapods length/width: 180 µm/110–120 µm, apical exterior with 13 branches. Procerus yellow, 20–50 µm high, 10–30 µm wide, with 7 long anal setae (258–283 µm). Supraanal seta 200 µm. Anal tubules not readily observable.

Remarks. In the specimens from China most characteristics agree with the description of Saether (1986a), but the higher ratio of thoracic horn/anal macrosetae (2.29–2.48) separates them from specimens of other regions (1.71–2.22). In the larval stage, the minor differences in Chinese, European and American specimens are as follows: (1) all the setae in seta interna of O. fulva fulva (Kieffer) are similar in size and shape, while in the specimens in Italy and China are thinner and shorter in the anterior and tapering to longer and thicker near the base of mola, but are divided into three parts in O. fulva nearctica Saether ; (2) the ventromental plate of Italian specimens and O. fulva nearctica Saether are wider than O. fulva fulva (Kieffer) and specimens in China; (3) All of them have two strong setae in the most lateral edge of ventromental plate, while in the O. fulva fulva (Kieffer) and in specimens from Italy and China the setae are stronger than for O. fulva nearctica Saether. In conclusion, specimens from collections in Italy and China are regarded as O. fulva fulva (Kieffer) .

Distribution. The species is widely distributed in the Holarctic Region. China (Palaearctic China: Xinjiang Uygur Autonomous Region).

Figures

FIGURES 1 – 11. Odontomesa fulva (Kieffer). Larvae. 1 — mentum; 2 — mandible. Pupae. 3 — sternites VIII – IX, male; 4 — frontal apotome; 5 — thoracic horn; 6 — tergites of male. Pharate adult male. 7 — genitalia, dorsal view (SVO, Superior volsella; MVO, Median volsella; IVO, Inferior volsella); 8 — genitalia, ventral view (Tsa, Transverse sternapodeme; AL, Aedeagal lobe; Pha, Phallapodeme). Pharate adult female. 9 — genitalia, ventral view; 10 — lobes of gonapophyses VIII (VIL, ventrolateral lobe; ApL, apodeme lobe; DmL, dorsomesal lobe); 11 — genitalia, dorsal view.