Cricotopus hillmani Drayson & Cranston

Drayson, Nick, Cranston, Peter S. & Krosch, Matt N., 2015, Taxonomic review of the chironomid genus Cricotopus v. d. Wulp (Diptera: Chironomidae) from Australia: keys to males, females, pupae and larvae, description of ten new species and comments on Paratrichocladius Santos Abreu, Zootaxa 3919 (1), pp. 1-40 : 13-15

publication ID	https://doi.org/ 10.11646/zootaxa.3919.1.1
publication LSID	lsid:zoobank.org:pub:218630EE-6BF7-4E35-A8F6-9E8260D60FA0
DOI	https://doi.org/10.5281/zenodo.6122642
persistent identifier	https://treatment.plazi.org/id/91FC9509-46AC-42DA-A4DC-6DE458C0BDA5
taxon LSID	lsid:zoobank.org:act:91FC9509-46AC-42DA-A4DC-6DE458C0BDA5
treatment provided by	Plazi
scientific name	Cricotopus hillmani Drayson & Cranston
status	sp. nov.

Treatment

Cricotopus hillmani Drayson & Cranston View in CoL , sp. n.

( Figs. 1 View FIGURE 1 F, 2F, 3G, 4F, 6E, 7G, 8F, 11B)

urn:lsid:zoobank.org: act :91FC9509-46AC-42DA-A4DC-6 DE 458C0BDA5

Cricotopus View in CoL ‘sp. IV’ Drayson, 1992: 73

Cricotopus View in CoL “hillman” sp. nov. Drayson & Cranston, in Cranston, 1996: 86 [Invalid; author states ‘not formal publication for nomenclatural purposes’]

Type material studied. Holotype Le/Pe/♂, AUSTRALIA: NSW: Shoalhaven R., Warri Bridge, 35°21'S 149°44'E, 15.iii.1992 (Cranston) ( ANIC). Paratypes: Le/Pe/♂, as holotype; NSW: 2 Pe, Warrumbungles, Shawn's Ck., Timor Rock, 31°16'S 149°09'E, 15.ix.1989 (Cranston), Pe, Endrick R., 6km N.E. Nerriga, 35°05'S 150°08'E, 1.ix.1988 (Cranston); 2 Le/Pe/♂, Pe, Shoalhaven R., Warri Bridge, 35°21S 149°44'E, 15.iii.1992 (Cranston); 1 Pe, Molonglo R., above Captain's Flat, 35°35'S 149°28'E, 7.iii.1989 (Cranston); Pe, Deua R., s.e. Araluen, 35°45'S 149°57'E, 6.ii.1989 (Cranston); 2 Pe, Albury, Murray R. Stn 6, 36°06'S 147°01'E, 26.vii.1989 (Cook); 8♂, 1♀, 68 Pe, L, Albury, Murray R., Waterworks, 36°07'S 146°54'E, 21.xi.1989 (Cook); 2 Pe, L, Rutherford Ck., Brown Mt., 36°36'S 149°47'E, 2.x.1989 (Cranston). ACT: Le /Pe/♀, 15 Pe, Cotter R., Vanity Crossing, 31°20'S 148°54'E, 4.xii.1991 (Drayson); 2 Pe, 3 L, Brindabellas, Blundell's Ck., 35°22'S 148°50'E, 13–16.iv.1988 (Cranston); ♂, Brindabellas, Blundell's Ck., 35°22'S 148°50'E, 7.i.1930 (Tonnoir) (misidentified by Freeman as C. annuliventris ); ♂, 3 Pe, 3 L, same except 13–16.iv.1988 (Cranston); ♂, ♀, Tidbinbilla, Tidbinbilla Ck., 35°27'S 148°57'E, 19.ii.1989 (Cranston); ♂, ♀, 4 Pe, Corin Rd, Gibraltar Falls, 35°28'S 148°55'E, 4.xii.1990 (Drayson); 2♂, Le/Pe/ ♀, 5 Pe, Gibraltar Falls, Corin Rd, 28.ix.1990, 35°28'S 148°55'E (Drayson). Vic: Pe, Wodonga, House Ck., downstream, 36°06'S 146°54'E, 6.ix.1989 (Cook); Pe, Wodonga, House Ck., upstream, 36°10'S 146°54'E, 6.ix.1989 (Cook); Le/Pe/♂, 2 Le/Pe/♀, Wodonga, Middle Ck., downstream White's Rd, 36°09'S 146°57'E, 24.i.1990 (Cook); 3 Pe, Wodonga, Middle Ck., Street's Rd, 36°11'S 146°56'E, 26.ii.1990 (Cook); Pe, Wodonga, Middle Ck., Beechworth Rd, 36°15'S 146°50'E, 26.ii.1990 (Cook); Pe, Upper Tambo R., USWW, 37°00'S 147°53'E, 8.iii.1990 (Hortle). Tas: Pe, Lake St.Clair NP, Old Pelion Hut, Douglas Ck., 41°50'S 146°01'E, 25.i.1990 (Cranston); Pe/♂, Mt. Field NP, Tyenna R., 160m a.s.l., 42°41'S 146°43'E, 6/ 7.ii.1992 (Cranston). SA: 2 ♂, Hindmarsh Falls, 4.xi.1970 (Hergstrom) (Hergstrom's proposed paratypes of “ C. parbicinctus ").

Other material examined. Qld: 3Pe, Herberton, Carrington Falls Ck, 800 m asl, 16°28'S 145°19'E, 9–10.iv.1997 (Cranston); L(P), nr Mareeba, Davies Ck., 17°01'S 145°35'E, 19–20.vi.1997 (Cranston). Pe, Eungella NP, Mt Dalrymple, Cattle Ck., 21°02'S 148°35'E, 22.iii.1998 (Cranston).

Molecular material. Qld: Bellthorpe NP, Stony Ck., 26°53'S 152°44'E, 5.xi. 2013, 191 m asl (Krosch) (Mv- Stny1.12, 1.18). NSW: L, Monga SF, Mongarlowe R., 35°23'S 149°55'E, 30.iv.2012 (Cranston) (Mv-Mong12-9); Pe, Brindabella, Goodradigbee R, 35°23'S 148°44'E, 27.vi.2012 (Cranston) (Mv-NSWGd5). ACT : L, Uriarra Ck., 35°14'S 148°57'E, 13.vi.2012 (Cranston) (Mv-UCk-2); 6L, Corin, Gibraltar Falls, 35°31'S 148°56'E, 3.vi.2012 (Cranston)(Mv-ACTGF21-26). Vic: 2L, Dobson’s Lane, Dandenong Ck., 37°50'S 145°19'E, 24.x.2006 (Carew) (Mv-DOL2, 4). Tas: L, Lake Saint Clair NP, Hugel R., 42°06'S 146°09'E, 1.xii. 2013, 770 m asl (Krosch) (Mv- TAS13.6.4); L, Mt Field NP, Russell Falls Ck., 42°40'S 146°42'E, 3.xii. 2013, 196 m asl (Krosch) (Mv- TAS 13.9.18). SA: 2♂, 3♀, 2Pe/♂, 2L, below Hindmarsh Falls, Hindmarsh R., 35º26'S 138º58'E, 3.x. 2013, 220 m asl, (Krosch & Cranston) (Mv-SAHF1.1, 1.2, 2.1, 2.2, 6.1, 7.1, 7.2, HF2, 6); 2Pe/♂, L, Sawpit Rd., Hindmarsh R., 35°28'S 138°35'E, 3.x.2013, 70 m asl (Krosch & Cranston) (Mv-SAW1, 3, HR6); 2L, Deep Creek Conservation Park, Tapanappa Rd, 35°36'S 138°14'E, 3.x. 2013, 260 m asl (Krosch) (Mv-DC3, 13); L, Minno Ck Junction, Sturt R., 35°02'S 138°37'E, 1.vii. 2013, 200 m asl (Madden) (Mv-StR1); L, Southern Mt Lofty Ranges, Waterfall Gully, First Ck., 34°58'S 138°40'E, 1.vii. 2013, 250 m asl (Madden) (Mv-Fst2); L, Southern Mt Lofty Ranges, Uraidla, Cox Ck., 34°58'S 138°44'E, 1.vii. 2013, 450 m asl (Madden) (Mv-Cox3).

Description. MALE ( Fig. 1 View FIGURE 1 F). 3.2–4.7 mm.

Head. Ant 800–112 µm; Fl 1–12, 336–440 µm, Fl 13, 440–650 µm; A.R. 1.2–1.5. Palp 415–472 µm. 3 Fr, 7–10 Po, Clyp moderately setose.

Thorax. Pale yellow brown with distinctive brown vittae on scutum and postnotum; scutellum pale. Laps 1–4, Ac 12–21, Dc 17–31, Pa 3–5, Scts 7–12.

Wing (n=2). 2.6–2.7 mm. Sq 14–18, R 6–8. Anal lobe moderately produced.

Legs. All legs mid-brown with proximal 2/3 of tibiae paler, notably on mid- and hind legs.

Abdomen. TI and IV pale to very pale yellow-brown, other tergites mid-brown. TIII and VI with lateral setal band connected posteriorly ( Fig. 3 View FIGURE 3 G).

Hypopygium ( Fig. 2 View FIGURE 2 F). Gcx 186–266 µm, iv with posteriorly projecting rounded lobe. Gst 77–106 µm, about 2/5 (0.37–0.42) Gcx, pointed apically; crista dorsalis strongly developed.

FEMALE (n = 5 + 3 pharate). As male except: 4.0– 4.9 mm.

Head. Ant 340–400 µm. Palp 468–504 µm. 3 Fr, 5–6 Po.

Wing (n=3). 1.8–2.1 mm. Sq 9–10; R + R 1 16–30, R4+ 5 9–12.

Thorax. Colour as male. Laps 1–4, Ac 9–21, Dc 17–31, Pa 3–5, Scts 7–12.

Abdomen. As male.

Genitalia. Spermathecae comprising mid-brown, elongate-ovoid capsules with narrow "neck" and curved ducts ( Fig. 4 View FIGURE 4 F).

PUPA. 3.1–5.0 mm, pale brown to very pale, almost hyaline, with noticeable dark adhesion scars on T I–VIII.

Cephalothorax. Slightly rugose dorsally. Th 80–120 µm, width 20–40 µm; hyaline, flattened, blunt, with or without rounded scales, especially distally ( Figs 6 View FIGURE 6 E, 7G). Fs 70–140 µm, on prefrons,

Abdomen ( Fig. 8 View FIGURE 8 F). PSB on segments II and III, less developed on III. Hook row on TII about 0.5 segment width but very variable (0.30–0.63). Ls VIII short (32–80 µm), Ls3 about 1/10 width of segment (0.08–0.14). Ms about 1/20 total length of abdomen (0.42–0.52). Dark adhesion marks on TII to VII.

4TH INSTAR LARVA ( Fig. 11 View FIGURE 11 B). 3.6 mm. H.l. 480–510 µm, pale to mid-brown with mid- to dark brown posterior rim; abdomen blue; procercus hyaline, sometimes with pale brown marking.

Head. Ant 74–90 µm, Fl 1, 44–50 µm, Fl 2–5, 28–36 µm; A.R. 1.29–1.56. Md 152–182 µm, about 2x ant (1.90–2.24), with smooth inner margin and weakly crenulate outer margin; pale brown with distal 1/3 mid-to dark brown. Mentum 116–144 µm, pale brown posteriorly, mid-brown anteriorly; 6 or usually 7 pairs of laterals, 2nd laterals slightly reduced, 7th laterals small to occasionally absent.

Abdomen. Pc 20–24 µm, A.s. 440–550 µm.

Etymology. The epithet for this species, ‘ hillmani’, recognises Dr. Terry Hillman, past Director of the Murray Darling Freshwater Research Centre, who supported taxonomic, ecological and biodiversity studies of the Chironomidae of the Murray River and tributaries in the Albury-Wodonga region.

Remarks. Adults of C. hillmani can be distinguished from all except C. varicornis by the combination of dark vittae on thorax and pale TI and IV. They can be distinguished from C. varicornis , for which the leg pattern is not known, only by the pattern of tergal setation, and the spermathecal capsule shape, both of which features may be unreliable. Pupae are easily recognised by the dark adhesion marks on all abdominal segments. The frontal setae are present on the prefrons, tergites I and II essentially bare of spines or spinules, and mid-paraterga spinulose. From the otherwise similar C. howensis , it can be distinguished by the thoracic horn bearing apical/subapical small tubercles ( Fig. 6 View FIGURE 6 E). Larvae can be recognised by the mandible having a moderately elongate apical tooth, crenulate outer and smooth inner margin, antennal blade reaching apex of antenna with large Lauterborn organs, and especially, but not always, the presence of a small 7th lateral tooth on the mentum.

As discussed below, Hergstrom (1974) included specimens of C. hillmani in her " C. parbicinctus ". A specimen in the A.N.I.C. collection was identified by Freeman as C. annuliventris , but the thorax, legs and abdomen clearly show it to belongs to C. hillmani .

C. hillmani is an essentially south-eastern Australian species (including Tasmania ) with an anomalous record from far north Queensland. Records are all from rivers and creeks in good water health.