Odontomesa ferringtoni Saether

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 : 138-141

Odontomesa ferringtoni Saether

( Figs. 12–19 )

Odontomesa sp. A Saether, 1986a: 26

Odontomesa ferringtoni Saether, 1986a: 25 ; Bolton, 1992: 149; Ashe & O'Connor 2009: 326

Diagnositic characters. The shape of the inferior volsella of male imagines, the long frontal setae situated on small cephalic tubercles of pupae, and the ratio of supraanal seta/anal setae of larval can separate the species from the other species of Odontomesa .

Materials examined. 4³31 P, U.S. A: New Mexico, San Juan Co., San Juan River at Bridge 1 mile west, San Juan Hospital. 29. ii.1976. R. Sta. F. 5³, U.S. A: Wash Columbia, Nat. Wildlife Ref., S.W. Moses Lake. 14.vi. 1976.

Veh. Collect. N. Jorgensen. 9L1P, U.S. A: New Mexico, San Juan Co., La Plata River at NM hiway 173, Sta. P2, 7. v. 1976. Ekman Dredge.

17P, U.S. A: New Mexico, San Miguel Co, Pecos R 200m below Lisboa Hat. 21.vii. 1992. Thienemann Samp. R. Castell. 8P, U.S. A: New Mexico, Santa Fe Co., Aiwai Bridge Rio Grande River near San Ildefonso between Santa Fe & Los Alamos. 5.x. 1974. Sta. D. 6P, U.S. A: New Mexico, Santa Fe Co., Aiwai Bridge Rio Grande River near San Ildefonso between Santa Fe & Los Alamos. 31.x. 1974. Sta. D. 2P, U.S. A: New Mexico, Santa Fe Co., Aiwai Bridge Rio Grande River near San Ildefonso between Santa Fe & Los Alamos. 29.ii.1974. Sta. D. 1P, U.S. A: New Mexico, Santa Fe Co., Aiwai Bridge Rio Grande River near San Ildefonso between Santa Fe & Los Alamos. 31.xi. 1974. Sta. D. 5P, U.S. A: New Mexico, Taos Co., Rio Costilla Trib., #1, ap. 5miles ab. Costilla Res. 19. ix. 1991. Thienemann Sample. M. Hatch. 4P, U.S. A: New Mexico, Quay Co. 14miles south, Nara Visa Canadian River at State Line. 29. ii. 1976. Sta. B. 2P, U.S. A: New Mexico, Navajo River at Bridge 1/ 4 miles north, New Mexico State Line between Lumberton, NM and Edith, Colorado. 9. ix. 1974. Sta. E. 1P, U.S. A: New Mexico, Navajo River at Bridge 1/ 4 miles north, New Mexico State Line between Lumberton, NM and Edith, Colorado. 17. vii. 1974. Sta. E. 3P, U.S. A: New Mexico, San Juan Co., San Juan R+Hwy 64 at Blanco. 11.ix.1991. Thienemann Samp. Milensky. Doles. 2P, U.S. A: New Mexico, Sandoval Co., East Fork Jemez R., Las Conchas Cpgd. 9.vii. 1993. UV Sample. S. Sanders. 2P, U.S. A: New Mexico, Guadalupe Co., Puerto de huna, Santa Rosa, Decos River. 29.ii.1976. Sta.A. 1P, U.S. A: New Mexico, San Juan Co., Animas River. 9.v.1976. Surber Sample. 1P, U.S. A: New Mexico, Catron Co., San Francisco River. 18.xi.1974. Sta.H. 1P, U.S. A: New Mexico, Rio Arriba Co. Rio Chamita at Seargant Ranch. 1.vii.1992. Thienemann Sample. Rich C. & Darrell J. 1P, U.S. A: New Mexico, Rio Arriba Co. Rio Chama below EI Vado. 10.xi.1991. Thienemann net. C.Z.Jacobi. 1P, U.S. A: New Mexico, Rio Arriba Co. Los Pinos R., USFS Area. 10.x. 1991. Doles, Milensky. 1P, U.S. A: New Mexico, Catron Co., Tularosa R. West of Apache Creek. 30. ix. 1991. Thienemann Samp. M. Doles. 1P, U.S. A: New Mexico, San Miguel Co. Pecos R., Terrero Bridge. 8.ix.1992. Thienemann Samp.

Pupa (n = 10). Total length 3.60–5.75, 4.79 mm. Exuviae brown.

Cephalothorax ( Figs. 15, 17, 18 ). Frontal setae 138–238, 178 µm long, setae apically on small cephalic tubercles. Ocular field with two 83–175, 111 µm long postorbitals, and 38–50, 41 µm (6) long vertical. Median antepronotals 118–163, 140 µm and 135–188, 151 µm long; lateral antepronotals 90–175, 124 µm and 90–220, 151 µm long. Thoracic horn large and broadest at apex, 450–600, 537 µm long, 165–230?215 µm wide; 2.28–2.50 times as long as anal macrosetae; often with a sub-apical notch (as in fig. 18). Anterior precorneal setae 113–200, 157 µm long; median setae 13–75, 35 µm long; posterior setae 25–125, 84 µm long. Anterior dorsocentral (Dc1) 125–183, 151 µm long; situated 45–128, 83 µm in front of Dc2. Dc2 95–175, 149 µm long; situated 235–355, 282 µm in front of Dc3. Dc3 and Dc4 each 75–150, 108 µm and 75–138, 111 µm long, 13–75, 47 µm apart. Prealars 43– 153, 99 µm long.

Abdomen ( Figs. 16, 19 ). L3 on segment III split into 3–6, 5 branches; on IV split into 4–6, 5 ranches. Distances from L3 of segment VIII to apex of caudolateral extension 88–150, 103 µm; length of extension 125–225, 162 µm. Anal lobe 360–525, 432 µm long and 150–205, 182 µm wide at base, with 5 subequal anal macrosetae 150–270, 217 µm long; and 47–59, 54 setae in fringe.

Fourth instar larva (n = 5). Total length 2.80–6.05 mm. Head capsule light brown. Head capsule length/ width: 425–475, 458 µm/375–420, 402 µm: 1.12–1.27.

Head. Antenna ( Fig. 13 ) with 4 flagellomeres. Lengths of antennal segments (µm): 78–83, 81; 28–31, 30; 3–4, 3; 2, 2. AR 2.24–2.37, 2.32. Basal antenna segment 18–20, 20 µm wide; distance from base to ring organ 24–27, 25 µm. Accessory blade 23–28, 25 µm long. Premandible 80–103, 93 µm long, with apical tooth 25–33, 28 µm and 25–38, 31 µm long. Mandible ( Fig. 12 ) yellow, 95–108, 103 µm long. Mentum ( Fig. 14 ) brown. Ventromental plates µm 45–60, 50 wide, 106–125, 110 µm long. Postmentum 125–158, 143 µm long.

Abdomen. Posterior parapods 150–300, 205 µm long. Procerus yellow, 25–38, 30 µm high, 50–60, 55 µm wide, with 6–7, 6 long anal setae (188–460, 310 µm). Supraanal setae 75–210, 143 µm, 0.40–0.55, 0.46 times as long as anal setae. Anal tubules 75–100, 85 µm long and 35–70, 54 µm wide at base.

Third instar larva (n = 1). Total length 1.78 mm. Head capsule light brown. Head capsule length/width: 250 µm/213 µm: 1.17.

Head. Antenna with 4 flagellomeres. Lengths antennal segments (µm): 40; 14; 2; 2. AR 2.22. Basal antenna segment 13 µm wide; distance from base to ring organ 13 µm. Accessory blade 18 µm long. Premandible 33 µm long, with apical tooth 13 µm and 15 µm long. Mandible yellow, 63 µm long. Mentum brown. Ventromental plates 16 µm wide, 50 µm long. Postmentum 56 µm long.

Abdomen. Posterior parapods 63 µm long. Procerus yellow, 19 µm high, 31 µm wide, with 6 anal setae (longest 153 µm). Supraanal seta 70 µm, 0.46 times as long as anal setae. Anal tubules 28 µm long and 19 µm wide at base.

Remarks. The pupae of the species can be distinguished from known pupae of the genus by the following combination of characters: frontal setae 138–238 µm long, setae apically on small cephalic tubercles; thoracic horn large and broadest at apex, sometimes with subapical notch; median precorneal setae very shorter (13–75 µm) than anterior precorneal seta; supraanal setae 75–210 µm, 0.40–0.55 times as long as anal setae. The shape of ventromental plates, the postmentum 125–158 µm long, in combination with the supraanal setae 75–210 µm, 0.40– 0.55 times as long as anal setae will separate the larva from both subspecies of O. fulva .

Saether (1986a) described an unnamed species “ Odontomesa sp. A” and separated it from O. fulva . Subsequently, Epler (2001) proposed larvae of O. ferringtoni could be differentiated from O. fulva by the basal external seta of the mandible. However, the relationship of “ Odontomesa sp. A” and O. ferringtoni remained unclear. Saether (1986a) remarked that “ Odontomesa sp. A” quite likely is conspecific with O. ferringtoni . After examining additional specimens and literature descriptions, the same characters of mandible and ventromental plate and the approximate measurements of abdomen in larva and pupal stages, we have found “ Odontomesa sp. A” with the less anal macrosetae (3) than O. ferringtoni (5) as recorded for one specimen in the original description, actually represents individual, intraspecific variation, and that “ Odontomesa sp. A” is conspecific with O. ferringtoni .

Distribution. Nearctic Region: U.S. A (Colorado, New Mexico, Ohio).

Figures

FIGURES 12 – 19. Odontomesa ferringtoni (Kieffer). Larvae. 12 — mentum; 13 — antenna; 14 — mandible. Pupae. 15 — frontal apotome; 16 — Segment I-VII; 17 — thoracic horn; 18 — thoracic horn (with subapical notch); 19 — sternites VIII – IX.