Pagastia (P.) donoliveri Makarchenko et Hansen, 2020

Makarchenko, Eugenyi A. & Hansen, Dean C., 2020, Pagastia (P.) donoliveri sp. nov. - a new Nearctic alpine stream chironomid species (Diptera: Chironomidae: Diamesinae) from the Beartooth Mountains, Wyoming U. S. A., Zootaxa 4755 (1), pp. 171-176 : 171-175

publication ID

https://doi.org/10.11646/zootaxa.4755.1.9

publication LSID

lsid:zoobank.org:pub:B3EC6807-4B94-4FC6-9B5C-FEC08A24B882

DOI

https://doi.org/10.5281/zenodo.3730247

persistent identifier

https://treatment.plazi.org/id/9E21409F-D361-41D5-B5A6-FF0857DC8C56

taxon LSID

lsid:zoobank.org:act:9E21409F-D361-41D5-B5A6-FF0857DC8C56

treatment provided by

Plazi

scientific name

Pagastia (P.) donoliveri Makarchenko et Hansen
status

sp. nov.

Pagastia (P.) donoliveri Makarchenko et Hansen , sp. nov.

( Figs. 1–9 View FIGURES 1–3 View FIGURES 4–5 View FIGURES 6–9 )

urn:lsid:zoobank.org:act:9E21409F-D361-41D5-B5A6-FF0857DC8C56

Material. Holotype: adult male, U.S.A.: Wyoming, Park County, Beartooth Pass region, Malaise trap over small stream feeding Frozen Lake , alt. 3127 m above sea level, N 44°57’42.12”, W 109°29’08.12”, 30–31.VIII.2017, leg. Dean C. Hansen. GoogleMaps Paratype: 1 adult male, same data as holotype GoogleMaps .

Derivatio nominis. The species is named in honour of the Canadian chironomid taxonomist Donald Raymond Oliver.

Adult male (n = 2).

Total length ca 5.4–5.6 mm.

Coloration (specimens in Euparal). Head, thorax, legs, and abdomen brown to dark brown; antennae light brown; wings greyish.

Head. Eyes bare and strongly extended dorsomedially ( Fig.1 View FIGURES 1–3 ). Temporal setae 33–52, including 4 coronals, 8– 14 preoculars, 14–22 verticals, and 7–11 postorbitals. Clypeus with 23–24 setae. Antenna with 13 flagellomeres and developed plume, these setae 328–590 μm long; pedicel with 3 setae 56–64 μm long; terminal flagellomere with 1 subapical setae 50–52 μm long; flagellomeres lengths (in μm): 72–76; 28; 24–28; 32; 36–40; 36–40; 40–44; 40–42; 42–44; 44; 44–52; 44–48; 592–636; AR 1.22–1.26. Palpomere lengths (in μm): 60–68; 96–100; 192–196; 168–208; 260. Palpomere 3 distally with sensilla capitata (diameter 12 μm). Palpomeres 1–5 length/head width 0.95–1.24.

Thorax. Antepronotum with 6–7 dorsal and 13–18 lateral setae. Acrostichals 19–26 (60–92 μm long), dorso- centrals 41–43 (in 1–2 rows in anterior 2/3 and in 3 rows in posterior 1/3), prealars 22–24, scutellars ca 55 ( Figs. 2–3 View FIGURES 1–3 ).

Wing. Length 4.28–4.36 mm; width 1.16 mm. Membrane with setae 20–24 μm long on wing apex. R and R 1 with 59–64 setae in 1–2 rows; R 4+5 with 34–35 setae. Setae on R, R 1, R 4+5 40–52 μm long. Costa extension 49–66 μm long. RM length/MCu length 2.5–3.3. Anal lobe developed, outline rounded. Squama with 40–46 setae 48–152 μm long, in 1–2 rows. VR 0.84–0.93.

Legs. Spur of fore tibia 88–92 μm long; spurs of mid tibia 68–72 μm and 72–76 μm; of hind tibia 112–116 μm and 72 μm long. Hind tibial comb with 10 setae. Lengths and proportions of leg segments as in Table 1.

Hypopygium ( Figs. 4–9 View FIGURES 4–5 View FIGURES 6–9 ). Tergite IX with 20–25 setae on each side 64–120 μm long. Anal point almost parallelsided in dorsal view, 72–88 μm long, with narrow seta-like apical peg 28 μm long ( Fig. 8 View FIGURES 6–9 ). Laterosternite IX with 7– 11 setae. Transverse sternapodeme narrow, anterior margin nearly straight. Phallapodeme with lateral aedeagal lobe only ( Fig. 5 View FIGURES 4–5 ), these 172–196 μm long, elongate and tapering to thin rounded apex. Gonocoxite 320–328 μm long, with basal plate and lobe-like median field. Gonostylus 196–224 μm long, narrow and ribbed, with rounded basal lobe in outer side and with lobe-like “heel” apically; megaseta 16–20 μm long ( Figs. 4 View FIGURES 4–5 , 6–7, 9 View FIGURES 6–9 ). HR 1.46–1.63.

Pupa and larva unknown.

Diagnosis. The male of the new species is most closely related to the Japanese species P. (P.) hidakamontana Endo , but it may be clearly distinguished from later by the shape of the gonostylus and some other features, namely the gonostylus with a rounded basal lobe in its outer side and a lobe-like “heel” apically; anal point of tergite IX 72–88 μm long, with narrow seta-like apical peg 28 μm long ( Figs. 4 View FIGURES 4–5 , 6, 7, 9 View FIGURES 6–9 ); AR 1,22–1,26. Gonostylus of P. (P.) hidakamontana with small basal lobe in outer side, apically rounded, without “heel”; anal point 100–116 μm long and apical peg broad, 24–33 μm long ( Endo 2004, Figs. 1–6 View FIGURES 1–3 View FIGURES 4–5 View FIGURES 6–9 ); AR 1.56–1.75. See also key below.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Chironomidae

Genus

Pagastia