Geochus kuscheli, Leschen, Davis, Brown, Brav-Cubitt, and Buckley, 2022

Leschen, Richard A. B., Davis, Steven, Brown, Samuel D. J., Brav-Cubitt, Talia & Buckley, Thomas R., 2022, The Enigmatic Dead-Leaf Miner Geochus Broun (Coleoptera: Curculionidae): Phylogenetic Placement, a New Species, and Lectotype Designations, The Coleopterists Bulletin 76 (1), pp. 1-35 : 16-20

GeOchUs hOwensis Lea, 1927 ( Figs. 15 , 17 )

Geochus howensis Lea 1927: 167 . Type locality: Lord Howe Island .

Type Depository. AMSA : LT, 1 PLT.

Distribution. Lord Howe Island.

Remarks. Lea based his description on 11 specimens collected from leaves by “A.M. Lea and wife”. We examined two specimens from AMSA, one we designate as the lectotype, to stabilize the epithet, with the other becoming a paralectotype.

Distinguished from other known Geochus species by the very flat dorsum, which is contiguous between the pronotum and elytra.

Type Material Examined. Lectotype, here designated ( AMSA): card-mounted, glued to card on left side, mounted on the same card as, and to the right of, the paralectotype, “Lord Howe I, A. M. Lea Lord Howe I A. M. Lea [dark olive label]//Australian Museum K 453673//K58440 [handwritten on pink label]// Geochus howensis [in Lea’s hand] Lea, Cotype [pink label]// SYNTYPE [printed] Geochus howensis Lea, 1927 [in unknown hand]” . Paralectotype ( AMSA): 1, mounted dorsally on same card as lectotype .

GeOchUs inaeqUalis (Broun, 1880) ( Figs. 4 , 5A , 11 , 12 , 15–16 )

Geophilus inaequalis Broun 1880: 446 . Type locality: Whangarei Harbour.

Geochus inaequalis (Broun, 1880) . Implied combination by Broun (1882: 128).

Type Depository. BMNH :LT,1 PLT; MHNP :1 PLT.

Distribution. New Zealand (ND).

Remarks. Broun did not indicate the number of specimens examined to establish this name for this “remarkable” species he found “amongst vegetable rubbish on the ground near Whangarei Harbour”. Three syntypes were located in the Broun collection (BMNH) and from MHNP, one that we designate as the lectotype to stabilize the epithet, with the two remaining specimens becoming paralectotypes. There were five additional specimens in the Broun collection (BMNH) labeled as variants and an additional MHNP specimen that only had the Broun number. All these we exclude from the syntype series.

This species forms a species group with G. frontalis , G. morosus , and G. nodosus , which can be distinguished from other Geochus species by the enlarged epifrons ( Figs. 3F , 4A ), and the V-shaped position of the tubercles on the elytra ( Figs. 4D , 15 ).

Pinned below G. ineaqualis in the Broun collection (BMNH) is a specimen from the Hunua Ranges, which Broun labeled as “ G. pictus ”; however, this name was never published and it is an unavailable name.

Type Material Examined. Lectotype, here designated ( BMNH): acetate card-mounted [with light green basal strip], “785. [olive label]// New Zealand. [red underline] Broun Coll. Brit. Mus. 1922-482.// Whangarei// Geochus inaequlis [in Broun’s hand]” . Paralectotypes: 1 ( BMNH), same but paper card-mounted, “785. [olive label]// New Zealand. [red underline] Broun Coll. Brit. Mus. 1922-482.// Manaia [lacking identification label]”; 1 ( MHNP), card-mounted, “785. [unknown hand, olive label]//

MUSEUM PARIS NOUVELLE-ZĖLANDE COMM BROUN 1914 [pink card]//Manaia// Geochus inaequlis [in Broun’s hand]// Geochus inaequlis Br. [unknown hand]”.

GeOchUs kUscheli Leschen, Davis, Brown, Brav-Cubitt, and Buckley , new species zoobank.org/ urn:lsid:zoobank.org:act:2AF7599A-F0B1-450F-BB34-6B81BE964458 ( Figs. 1–3 , 8–10 , 15 )

Diagnosis. Body form elongate. Dorsal vestiture consisting of sparse scales arising from the center of pronotal punctures or along elytral interstriae. Rostrum lacking carinae and somewhat elongate. Mandible with incisor lobe bidentate (left) and tridentate (right). Maxillary palpus with apical palpomere slightly more than 1.5× as long as penultimate palpomere. Pronotum constricted at apical 1/3, sides and dorsal outlines not confluent with elytra, widest at basal 1/3; disc with large punctures, separated from each other by less than 0.5× their diameter. Proventer with a distinct depression present, margined posteriorly; notal lobes with weak but distinct suture at middle. Elytra lacking a sharp lateral edge, disc carinate and not undulate, with well-developed and deeply impressed punctate striae; interstriae 3 and 5 raised along anterior 1/6. Transverse suture between abdominal ventrites 1 and 2 present at middle. Abdominal ventrite 5 of female with apical semicircular fovea. Penis with well-sclerotized ostiolar canal, bearing two flat, triangular sclerites; internal sac partially covered with minute setiform spines and scale-like vestiture, with well-defined flagellum/internal sclerite. Female spermatheca falciform and annular. Protibia with dorsal margin slightly swollen and clothed with a tuft of thick setae but not developed into a strong elbow or tooth. Tarsal formula 5-5-5 (pseudotetramerous, appearing 4-4-4), claw present.

Description. Total length 1.80–2.00 mm. Body somewhat narrow ( Fig. 1 ), about 1.79× as long as wide, dorsoventrally compressed. Color light tan to dark brown, sometimes unicolorous or mottled; de- cumbent scales pale, longer on legs and reduced in length on ventral surfaces. Dorsal surfaces subglabrous and punctate; alveolate microsculpture (sensu Harris 1979) present throughout, sometimes striate on rostrum. Head impunctate. Rostrum ( Figs. 2A–B ) lacking carinae, about 4× longer than width of eye; scrobes parallel to rostrum. Eye coarsely faceted ( Fig. 2A ), at most 4 facets long by 5 facets wide. Antennae ( Figs. 1 , 2A ) inserted at distal 1/3 and extending to edge of pronotum; scape about as long as funicle, antennomeres of funicle not greatly elongate; antennomeres 2 and 3 equal in length; antennomeres 4–8 equal in length and slightly short- er than antennomeres 2 and 3; antennal club about as long as antennomeres 4–8 combined. Mandible ( Figs. 10C–D ) with incisor lobe bidentate (left) and tridentate (right). Maxillary palpus ( Fig. 10B ) with apical palpomere slightly more than 1.5× as long as penultimate palpomere, palpomere 1 equal to 2 and 3 combined (2 and 3 of equal widths). Labial pal- pomeres 2 and 3 subequal ( Fig. 10A ), 1 about 1.2× longer than 2. Pronotum about 0.97× as wide as long, widest at about basal 2/3; constricted at apical 1/3, sides at basal 2/3 weakly curved, dorsal and lateral outlines not confluent with elytra, widest at basal 1/3; lacking a median line and punctation coarse, punctures larger than eye facet and separated at most by 1 puncture diameter. Proventer with a distinct depression present, margined posteriorly; notal lobes with weak but distinct suture at middle. Elytra ( Figs. 1 , 2D ) about 1.25× as long as combined width and 1.09× as long as pronotum, atten- uate at apical fourth and not evenly rounded; lacking a sharp lateral edge, disc carinate and not undulate or distinctly tuberculate, with 9 well-developed and deeply impressed striae that are usually deeply punctate and always separated by carinae, carinae at middle sometimes forming tubercules; striae 1 and 9 ending at apex, remainder ending subapically. Mesoventrite length longer than width of mesocoxal cavity. Abdominal ventrite 5 of female with apical semicircular fovea. Male ( Figs. 8A–C , 9A–C ) with penis evenly curved in lateral view, apex deflexed, in dorsal view weakly parallel-sided and subacute apically, with well-sclerotized ostiolar canal bearing two flat, triangular sclerites; internal sac partially covered with minute setiform spines and scale-like vestiture, with well-defined flagellum/internal sclerite; median struts (temones) short, less than 1/3 length of median lobe; sternite VIII divided into two small, narrow sclerites; sternite IX with deep narrow median concavity at posterior margin, anterior margin projecting, lobed. Female ( Figs. 8D , 9D–E ) with falciform, annular spermatheca. Protibia not strongly elbowed, angled or toothed, at most weakly wid- ened at basal fourth. Tarsal formula 5-5-5, claws present ( Figs. 3A–B ).

Comments. Geochus kuscheli is easy to distinguish from its congeners by the presence of tarsomere 5, which possesses tarsal claws. The placement of this species at the base of Geochus in our phylogeny is equivocal as regards generic placement, and specimens of this species in NZAC were labeled as a new genus by Willy Kuschel. However, based on its otherwise similar structures to members of Geochus , including internal features, we have decided to place G. kuscheli within the genus. A similar situation exists between Viticis , which lacks tarsomere 5, and Tivicis Morimoto , which has retained the claw. Some consider these taxa to be full genera ( Morimoto 1983; Pullen et al. 2014), and others synonymous ( Kuschel 2008).The morphological variation of the tarsomere in viticiines requires further study.Future studies combining morphological and molecular data that include a more complete sampling of Geochus species, including taxa from New Caledonia and representatives of other viticiine genera, will help to determine if this claw-bearing species war- rants separate generic status.

Etymology. Named for Guillermo (Willy) Kuschel (1918–2017) in recognition of his signifi- cant contributions to weevil systematics.

Type Material. Holotype (sex unknown); labelled, “ NEW ZEALAND FD Secretary I Gut Bay 23 Nov 1981 C.F. Butcher /Sifted litter around hut, 81/177” ( NZAC) . Paratypes (n = 112; coordinates added in brackets): New Zealand, Fiordland. 20 ( ANIC, BMNH, CMNC, NZAC, MNHW), Manapouri, Wilmott Pass, 300–650m, Jan 70, I Townsend ,

Litter [45°30.471′S, 167°11.492′E]; 1 ( NZAC), Casswell Sound, Stillwater, 11.4.46, R. R. Foster [45°2.878′S, 167°18.538′E]; 2 ( NZAC), Lake Manapouri, 26.4.52, R.W. Hornabrooke, leaf mould, A.W. Brooke Coll. Acc 1456.9.2 [45°33.965′S, 167°36.307′E]; 3 ( NZAC), Resolution I, Disappointment Cove, 26 May 1982, C.F. Butcher, Sifted Litter 82/61 [45°36.569′S, 166°40.232′E]; 5 ( NZAC), same as holotype [45°17.725′S, 166°57.396′E]; 1 ( NZAC), same as holotype but, Litter & rotten wood 81/179; 2 ( NZAC), same as holotype but, Beech litter & rotten wood around hut 81/180; 2 ( NZAC), Secretary Is, Grono Bay, 24 Mar 1984, C.F. Butcher, Sifted litter 84/57 [45°17.103′S, 166°56.563′E]; 2 ( NZAC), Secretary Is, nr Gut Hut, 22 Nov–1 Dec 1981, C.F. Butcher, Pan trap [45°17.725′S, 166°57.396′E]; 3 ( NZAC), Bauza I, 19 Mar 1984, C.F. Butcher, Litter 84/55 [45°16.830′S, 166°53.524′E]; 1 ( NZAC), same but, 27 Nov 1981, Litter & moss 81/187; 17 ( NZAC, USNM), Breaksea Sd, Gilbert I No 6, May 1982, C.F. Butcher, ex litter R 1–3, [45°35.951′S, 166°40.233′E]; 1 ( NZAC), same but, moss; 4 ( NZAC), same but, ex litter/rotten wood; 2 ( NZAC), same but, 12 Mar 1983, Litter 83/52; 2 ( NZAC), Dusky Sd, Seal Is, 7 Mar 1983, C.F. Butcher, Sifted litter 83/50a [45°45.417′S, 166°34.256′E]; 1 ( NZAC), Dusky Sd Passage I, 8 Mar 1983, C.F. Butcher, Moss 83/49 [45°45.993′S, 166°34.236′E]; 1 ( NZAC), same but, Litter 83/53; 1 ( LUNZ), Fiordland NP, Deep Cove, 1.ii.1983, Litter in forest, J. W. Early [45°27.132′S, 167°8.681′E]; 3 ( LUNZ), same but, 400 m; 1 ( NZAC), Secretary Island, Between Grono Bay & Gut hut, 45°17.612′S 166°57.052′E, alt: 2–20m, 4 March 2010, S.A. Forgie, sifting litter/rotten logs. SAF029; 28 ( NZAC), Dusky Sound, Gilbert Islands, 45°46.047′S 166°39.595′E, alt: 10–80 m, 25 January 2011, S.A. Forgie, sifting litter/bark/lichen/moss/log scrapings, SAF042; 1 ( NZAC), Dusky Sound, Resolution Island, Duck Cove 45°42.633′S, 166°39.041′E, alt: 1–20m, 21 January 2011, S.A. Forgie, sifting litter/bark/lichen/moss/log scrapings, SAF043; 8 ( NZAC), Dusky Sound, Resolution Island, Acheron Passage (NE. Side) 45°42.633′S, 166°39.041′E, alt: 5 m, 22 January 2011, S.A. Forgie, sifting litter/bark/lichen/moss/log scrapings, SAF044.

Figures

Fig. 15. Elytral outlines for representatives of each of the Geochus species groups.

Fig. 17. Dorsal habitus photographs of representatives of the type series or holotypes of Geochus arranged into informal groups.

Fig. 4. SEM images, Geochus inaequalis. A) Enlargement of frons and dorsal surface of rostrum, B) Enlargement of setae/scales on dorsal surface of rostrum, showing canal openings of wax glands (arrows), C) Mesonotum, D) Left elytron, E) Enlargement of scale on elytron, showing canal opening of the wax gland, F) Protarsus, the arrow indicating absence of pretarsal claw (dorsal aspect).

Fig. 5. SEM images. A) Geochus inaequalis, protarsus, the arrow indicating absence of pretarsal claw (ventral aspect). G. rufipictus: B) Head (dorso-anterior aspect), C) Enlargement of frons and dorsal surface of rostrum, D) Mesonotum, E) Left elytron. F) G. rugulosus, mesonotum.

Fig. 11. Geochus inaequalis, confocal microscope images. Mouthparts: A) Labium, ventral view, B) Maxilla, ventral view, C) Left mandible, dorsal view, D) Right mandible, dorsal view. E) Ventral portion of rostrum apex with mouthparts (mandibles removed), showing pharyngeal plate (arrow), F) Pharyngeal plate showing the location of the anterior and posterior arms, and the fully sclerotized base of the plate (arrow).

Fig. 12. Geochus inaequalis, female terminalia, confocal microscope images. A) Sternite VIII and spermatheca, B) Enlargement of sternite VIII, C) Enlargement of spermatheca.

Fig. 16. Dorsal habitus photographs of representatives of the type series or holotypes of Geochus arranged into informal groups.

Fig. 3. SEM images. Geochus kuscheli, new species: A) Protarsus, showing presence of pretarsal claws (dorsal aspect), B) Protarsus, showing pretarsal claws (ventral aspect), C) Enlargement of spatulate setae on ventral surface of protarsus, D) Pro- and mesothorax, lateral aspect, showing partially fused meta- and metepisterna, E) Enlargement of metepisternum, showing stellate setae/fimbriate scales. F) G. inaequalis, head (dorso-anterior aspect).

Fig. 1. Habitus photographs of Geochus kuscheli, new species. A) Dorsal view, B) Ventral view, C) Lateral view.

Fig. 2. SEM images, Geochus kuscheli, new species. A) Head (dorso-anterior aspect), B) Enlargement of frons and base of rostrum, C) Mesonotum, D) Left elytron, E) Enlargement of scales on elytron, F) Enlargement of scale, showing canal opening of the wax gland.

Fig. 8. Geochus kuscheli, new species, male (A–C) and female (D–E) terminalia. A) Aedeagus, dorsal view, B) Aedeagus, lateral view, C) Sternites VIII (with spiculum gastrale) and IX, D) Spermatheca, E) Sternite VIII.

Fig. 9. Geochus kuscheli, new species, male (A–C) and female (D–E) terminalia, confocal microscope images. A) Aedeagus, dorsal view, B) Aedeagus, lateral view, C) Sternites VIII (with spiculum gastrale) and IX (arrow), D) Sternite VIII and spermatheca, E) Enlargement of spermatheca in D.

Fig. 10. Geochus kuscheli, new species, confocal microscope images. Mouthparts: A) Labium, ventral view, B) Maxilla, ventral view, C) Left mandible, dorsal view, D) Right mandible, dorsal view. E) Dorsal view of the apicoventral portion of rostrum showing pharyngeal plate (arrow), F) Lateral view of meso- and metathorax showing reduced hind wing.