Irenimus parilis Pascoe, 1876

Brown, Samuel D. J., 2017, A revision of the New Zealand weevil genus Irenimus Pascoe, 1876 (Coleoptera: Curculionidae: Entiminae), Zootaxa 4263 (1), pp. 1-42 : 20-22

5. Irenimus parilis Pascoe, 1876

Figures 11, 12 , 25, 26 , 30, 31 , 37 , 65, 66, 67, 68, 69, 70, 71, 72 , 86

Irenimus parilis Pascoe, 1876:54

Diagnosis. Medium to large species; ovate, grey. Scape with appressed scales. Elytra with a slight swelling on interstriae 3. Males with ventrite 1 depressed. Female with ventrites simple. Metatibial apex with a broad corbel; strongly emarginate ventrally.

Description. Body length 4.41 mm to 6.95 mm (X = ̄ 5.75 mm, s = 1.03, n = 7) Integument black. Dorsum densely covered with light brownish grey to dark greyish brown appressed scales, pale V on elytral declivity of varying conspicuousness, pronotum occasionally with an elongate pale medial macula. Profemora and mesofemora unicolorous; metafemora with band of pale scales in distal 1/4, often obscure. Tarsi integument deep orange to strong red. Rostrum. Length 1.04 mm to 1.71 mm (X = ̄ 1.29 mm, s = 0.23, n = 7), width 0.60 mm to 0.92 mm (X = ̄ 0.77 mm, s = 0.11, n = 7), length/width ratio 1.54 to 1.86 (X = ̄ 1.67, s = 0.14, n = 7). Epifrons with appressed scales overlapping; elongate scales claviform, semi-erect to decumbent, mixed dark and pale; medial and lateral carinae evident. Dorsal carina strongly arched over antennal insertions. Lateral area ventrally of antennal insertions with coarse setae, but without appressed scales. Antennae. Scape when in repose reaching beyond hind margin of eye; covered with appressed scales and setae. Funicular segments loosely articulated; segment 1 clavate, 1.7 times longer than 2; segment 2 clavate, 1.3 times longer than segment 3; segments 3 to 7 clavate, subequal in length. Head. Eyes ovate. Pronotum. Length 1.32 mm to 1.96 mm (X = ̄ 1.55 mm, s = 0.22, n = 7), width 1.41 mm to 2.13 mm (X = ̄ 1.79 mm, s = 0.24, n = 7), length/width ratio 0.81 to 0.94 (X = ̄ 0.87, s = 0.05, n = 7); widest in anterior 1/ 3, lateral margins evenly curved. Anterior margin entire, posterior margin curved. Disc topography evenly convex; appressed scales appressed to overlapping; elongate scales claviform, semi-erect, mostly dark. Postocular lobes moderately developed. Anterior transverse groove weak beyond level with ventral margin of eye. Posterior transverse groove weak. Lateral posterior margin with inflection 1/3 of way from top. Elytra. Length 2.62 mm to 4.56 mm (X = ̄ 3.77 mm, s = 0.68, n = 7), width 1.98 mm to 2.95 mm (X = ̄ 2.58 mm, s = 0.36, n = 7), length/width ratio 1.04 to 1.64 (X = ̄ 1.47, s = 0.20, n = 7). Anterior margin curved posteriad, humeral angles rounded. Appressed scales overlapping. Elongate scales claviform, semi-erect, dark on disc, mostly dark laterally and posteriorly. Striae moderately impressed, interstriae slightly convex. Thoracic ventrites. Mesoventral process truncate. Metaventrite densely covered with appressed scales. Abdomen. Ventrites densely clothed with inner vestiture almost exclusively of appressed scales. Apex rounded. Males with ventrite 1 depressed medially, ventrite 5 shallowly concave. Females with ventrite 1 flat, ventrite 5 flat. Legs. Males with ventral margin of mesotibiae forming a blunt tooth at the proximal 1/3 ( Figure 37 ). Females with mesotibiae wider in proximal 1/3 than distal 1/3, but without obvious tooth. Metatibiae with corbel present, broad, bare; ventral margin of apex strongly emarginate. Male genitalia. Figures 65–68 . Penis with apex broadly truncate; lateral margins constricted medially; dorsal plate narrowed medially. Endophallus without proximal sclerites; aggonoporial sclerite with anterior lobes very short, posterior lobe fused. Female genitalia. Figures 69–72 . Sternite 8 with blade elongate. Styli elongate. Vagina sclerotised. Bursa copulatrix long, two small triangular sclerites present close to opening of oviduct. Spermatheca slender. DNA Sequences: COI. KX191336 , KX191346 . 28S. KX191805 , KX191906 , KX191916 . ArgK. KX191529 , KX191618 , KX191628 . CAD. KX 191077 , KX 191087 .

Type material examined. Holotype. Male (BMNH). Glued to card point; abdomen removed for dissection, specimen otherwise with hole in right elytron where formerly pinned, right protarsus missing segments 3–5 and right antenna missing club and funicle segment 7. Dissected material in genitalia vial pinned below labels. Labelled ‘Type’ [printed, round label with red border], ‘NZ / Christchurch’ [handwritten, Pascoe’s hand; off-white oval label], ‘ Irenimus / parilis / Type Pasc’ [handwritten, Pascoe’s hand; small off-white rectangular label], ‘ Irenimus / parilis Pasc’ [handwritten, Pascoe’s hand; off-white rectangular label with black border], ‘BMNH(E) / 1237417’ [printed, white rectangular label], ‘HOLOTYPE / Irenimus / parilis / Pascoe 1876 / Confirmed SDJ Brown 2013’ [printed, red rectangular label].

Although Pascoe (1876) does not explicitly state how many specimens made up the type series, it consisting of only a single specimen can be inferred by his not stating a size range in the description. Only a single Pascoe specimen is found in BMNH, with a label stating that it is a ‘Type’ in Pascoe’s hand. In the absence of other known type material, this is here regarded as the holotype.

Non-type material examined. A total of 115 specimens examined (6 males, 11 females, 98 of undetermined gender).

TO: Chateau Tongariro [-39.1996, 175.5393, A], 1–31 Dec 1948, Forster RR ( NZAC: 1). RI: Totara Reserve, Pohangina Valley [-40.1371, 175.8442, A] , 18 Dec 1948, Brookes AE (NZAC: 2); Vinegar Hill [-39.9262, 175.6233, A], 18 Oct 1965, Johns PM, Podocarp (CMNZ: 2). WI: Ashhurst [-40.294, 175.7581, A], 17 Jan 1959, Townsend JI (NZAC: 1). NC: Waikuku [-43.2976, 172.6861, R], 13 Dec 2012, Shields MW, Beaten from tall weeds in waste area (LUNZ: 1); Waikuku [-43.2976, 172.6862, R], 13 Dec 2012, Shields MW, Brown SDJ, Beaten from tall mallows in weedy waste area (LUNZ: 2); Weka Pass [-42.9802, 172.6712, A], 27 Oct 1996, Patrick BH, 250 m (OMNZ: 1). MC: Christchurch [-43.5326, 172.6362, A], 30 Oct 1961, Mckenzie R (NZAC: 1); Halkett Rd [-43.501, 172.3202, A], 14 Oct 1979, Waller J, Ex Blackcurrants (NZAC: 4); Halkett Rd [-43.501, 172.3202, A], 14 Sep 1979, Waller JB, ex Blackcurrants (LUNZ: 6); Halkett Rd [-43.501, 172.3202, A], 15 Dec 1976, Waller JB (NZAC: 2); Harewood [-43.4811, 172.5461, A], 5 Dec 1973, Trott NI (NZAC: 1); Harewood [-43.4811, 172.5461, A], 5 Dec 1973, Trott NI, In raspberry garden (NZAC: 1); Lincoln [-43.642, 172.4899, A], 1–31 Oct 1962, Ex pasture (NZAC: 32); Lincoln [-43.642, 172.4899, A], 14 Nov 1967, Jessop CT (NZAC: 2); Port Hills [-43.6086, 172.6443, A], 1–31 Dec 1916, Lindsay ( NZAC: 1); Templeton Research Farm , 9 Sep 1981, Rhodas P, Goldson S (NZAC: 1); Waimakariri Rd [-43.4753, 172.5661, A], 14 Aug 1984, Moody D (NZAC: 1); West Melton [-43.5268, 172.3721, A], 1–31 Oct 1993, Waller JB, In house ( LUNZ: 1) ; West Melton [-43.5268, 172.3721, A], 2 Oct 1990, Waller JB, ex grapes ( LUNZ: 29, USNM: 2) ; West Melton [-43.5268, 172.3721, A], 3 Oct 1972, Smale PE ( NZAC: 3) ; West Melton [-43.5268, 172.3721, A], 3 Oct 1972, Smale PE, Damaging current bushes ( NZAC: 3) ; West Melton [-43.5268, 172.3721, A], 6 Dec 1976, Waller JB, Ex lemon tree (Lisbon) ( LUNZ: 7).

Distribution. North Island, South Island: TO, RI, WI / NC, MC /—( Figure 86 ).

TO: Ruapehu. RI: Hunterville; Pohangina Valley. WI: Ashhurst. NC: Waikuku; Weka Pass. MC: Christchurch; Harewood; Lincoln; Port Hills; Templeton; West Melton.

Elevational range. Label data: 250 m (n = 1). Georeferenced data: 7 m to 1122 m (X = ̄ 80 m, s = 120, n = 106).

Biology. This species has been collected in large numbers on fruit trees and shrubs, including blackcurrants ( Ribes nigrum L., 1753), grapes ( Vitis vinifera L., 1753) and lemons ( Citrus × limon (L.) Burman f. cv. ‘Lisbon’). It has also been collected from agricultural pasture and from tall weeds, including mallows ( Malva sylvestris L., 1753).

Remarks. The disjunct distribution of this species is intriguing. Inspection of male genitalia of specimens from Ruapehu and the Pohangina Valley confirm that the North Island populations are conspecific with specimens from Christchurch. It is hypothesised here that the North Island populations are a human-assisted introduction from a South Island source population.

Figures

FIGURE 37. Left mesotibia of Irenimus parilis male, showing blunt tooth in proximal 1 / 3.

FIGURE 86. Distributions of Irenimus duplex (circles), I. parilis (squares) and I. thoracicus (triangles).

FIGURES 9 – 14. Habitus photographs of Irenimus males. 9, 10: I. duplex. 11, 12: I. parilis. 13, 14: I. thoracicus, holotype. Scale bars = 1 mm.

FIGURES 23 – 28. Habitus photographs of Irenimus females. 23, 24: I. duplex. 25, 26: I. parilis. 27, 28: I. thoracicus. Scale bars = 1 mm.

FIGURES 29 – 34. Left metatibia, anterior view. 29, Irenimus minimus; 30, Irenimus parilis; 31, Irenimus parilis, apical view; 32, Irenimus duplex; 33, Irenimus duplex, apical view; 34, Chalepistes compressus. Abbreviations: cl – corbel; sc—setal comb; ve—ventral emargination. Drawings not to scale.

FIGURES 65 – 72. Genitalia of Irenimus parilis. 65, penis, dorsal view; 66, aedeagus, lateral view; 67, male hemisternite 8 and spiculum gastrale, lateral view (muscles between hemisternite 8 and basal plate indicated); 68, male hemisternite 8 and spiculum gastrale with basal plate, ventral view; 69, tergite 8, dorsal view; 70, ovipositor, dorsal view; 71, ovipositor and spermatheca, lateral view; 72, sternite 8, ventral view. Scale bars = 0.5 mm; 65 – 68 at same scale; 69 – 72 at same scale.