Rhinolaemus niueensis Thomas, 2016

Thomas, Michael C., 2016, A revision of the genus Rhinolaemus Steel (Coleoptera: Laemophloeidae), Insecta Mundi 2016 (505), pp. 1-17 : 4-5

Rhinolaemus niueensis Thomas , n. sp.

Fig. 2, 3 , 7, 8 , 12-19 , 24-27

Types: Holotype, male, with label data: “ NIUE Liku F. 21 Sep 1975 G. Kuschel ”; allotype, female, with label data: “ NIUE Liku F. 21 Sep 1974 G. Kuschel ”/“Rhinolaemus n. sp. cf Steel 1954 Proc. R. E. S. (13) 23: 143–145”/“Rhinophloeus [sic] sp. 1”. Both deposited in NZAC.

Diagnosis. The combination of the following character states distinguishes individuals of this species from other members of Rhinolaemus : Head with distinct rostrum ( Fig. 7–8 ); antennal scape not distinctly sinuate, antennal insertion visible in dorsal view ( Fig. 12 ); some punctures on head arranged in oblique rows ( Fig. 13 ); body bicolored testaceous and brown; elytral maculae complete ( Fig. 2–3). Length, 2.7–4.2mm.

Description (male): 3.9mm long; elongate ovate; dorsal surface dark testaceous, legs and antennae paler; elytra bicolored dark and light testaceous; the dark markings ( Fig. 2–3) as follows: humerus, below scutellum on cell 1 and sometimes cell 2; in cell 3 at basal third; in cells 1 and 2 at midppoint; in cell 1 at apical third; in cells 1 and 2 at apex, producing a sinuate pale marking on each elytron; underside uniformly testaceous.

Head: 1.3× wider than long; broadly rostrate ( Fig. 8 , 12 ), rostrum comprising 0.57× head length; median longitudinal line complete almost to epistome; epistome with five emarginations: a central deep emargination over labrum; more shallow emarginations over mandibular insertions, and slight emarginations over antennal bases, located laterally on rostrum. Surface of head punctate, not microreticulate; punctures circular anteriorly, about size of eye facet, separated by about 1 diameter; much larger basally, narrowly separated and arranged in oblique rows ( Fig. 13 ), so that the punctures form furrows; each subtending a golden, coarse seta, much longer than a puncture anteriorly, about twice puncture length laterobasally. Mandibles ( Fig. 12 ) narrow and long, subequal in length to head; both sets of palpi ( Fig. 16 ) very long; maxillary palps attaining apex of mandible; labial palps almost as long; galea elongate and prominent, almost attaining tip of mandibles; ligula deeply emarginate; labrum prominent, deeply emarginate. Antennal insertions exposed in dorsal view ( Fig. 12 ); antennae long and slender, nearly attaining elytral apex; scape elongate, slender, gradually broadened apically; pedicel elongate, parallel-sided, 0.6× length of scape; antennomeres III–VII elongate, slender, slightly increasing in length; VIII about length of III; antennomeres IX–XI forming an elongate, indistinct club ( Fig. 14 ); IX about length of VI, X shorter, about length of III; XI longest, longer than scape; apices of IX–XI infuscate apically. Eyes moderate in size, comprising about 0.3× length of head; not very convex, finely faceted.

Thorax: Pronotum ( Fig. 8 ) 1.5× wider than long, broadest behind anterior angles, 1.5× broader than at narrowest point; gradually curved to basal angle; anterior angle acute, produced anteriorly, posterior angle obtuse, not produced; surface punctate, not reticulate; punctures small, oblong, smaller than eye facet, separated by 1–2 diameters; each subtending a long, golden, coarse, seta, much longer than puncture.

Elytra: 1.6× times longer than wide ( Fig. 15 ); broadest at about basal third, gradually narrowing posteriorly, apices conjointly rounded, not produced. Surface longitudinally uneven; punctate, not reticulate; punctures small, more or less arranged in rows; each subtending a long, coarse setae, corresponding in color with cuticle, i.e., pale areas with pale setae, darker areas with dark setae. Inner margin of third cell represented by a groove that extends nearly to apex; inner margin of first cell represented by groove extending from about apical third nearly to apex. Lateral margin moderately explanate; epipleuron wide basally, gradually narrowing apically, nearly attaining apex.

Male Genitalia: as in generic description ( Fig. 26–27 ); claspers with peg setae ( Fig. 25 ).

Female Allotype: Length, 4.2mm. Coloration, punctation, and pubescence as in male. Rostrum longer, comprising 0.6× total length of head, and narrower than in male ( Fig. 7 ); mandibles proportionally shorter, comprising 0.6× length of head; labrum evenly rounded anteriorly, not emarginate ( Fig. 7 ). Antennae attaining about apical third of elytra. Pronotum ( Fig. 7 ) not as expanded apically as in male, width at apex and at base subequal.

Variation: Paratypes range in length from 2.7mm to 4.2mm.

Distribution. Known only from Niue, a small (260 km 2) coral island located about 1,224 kilometers east of Viti Levu, Fiji. It is at 19 o 02' S, 169 o 52' W. Its highest elevation is 68m (CIA).

Biology. Some of the paratypes are labeled as having been collected on Polyscias multijuga (A. Gray) (Araliaceae) . Two were collected at light.

Paratypes. 51, as follows: 19 (12f, 7m), “ NIUE Liku F. 21 Sep 1975 G. Kuschel ” ( FSCA 1m) ; 1m “ NIUE Liku F. margin 21 Sep 1975 G. Kuschel ” ; 1f, “ NIUE Liku F. 21 Sep 1975 G. Kuschel ”/”Rhinophloeus sp. 1”/”Rhinolaemus sp. n. R.D. Pope det. 1976” ; 5(4f, 1m). “ NIUE Liku F. 20 Sep 1975 G. Kuschel ” ; 14 (7f, 6m), “ NIUE Liku F. 16 Sep 1975 G. Kuschel ”/“at night” ( FSCA 1 f; USNM, 1m, 1f; BMNH, 1m, 1f) ; 1f, “ Forest area (felling) nr. Liku Niue 16/9/ 75 P. A. Maddison M.V. Light ”/“N1682”/“UNDP/FAO Pest & Disease Survey 1972–1978 Deposited Ent. Div. DSIR Auckland” ; 6 (4f, 2m) “ NIUE Liku F. 15 Sep 1975 G. Kuschel ”/“ on Polyscias multijuga ” ( BPBM, 1f, 1m) ; 1m, “ NIUE Alofi South 21 Sep 1975 G. Kuschel ” ; 1f “ NIUE Alofi Liku Rd 22 Sep 1975 G. Kuschel ” ; 1m, “ NIUE 2 km E Alofi South 23 Sep 1975 G. Kuschel”/ “at night” ; 1f, “ NIUE ISLAND Central 8 Jun 1975 J.S. Dugdale ”/ at light”. All paratypes, unless indicated otherwise, are deposited in the NZAC .

Etymology. The species is named for the island of Niue, the only place it is known to occur. The island name is pronounced NEE-way (in litt., John Marris), so that the standard construction of the name, niueensis , is not as unpronounceable as it appears.

Discussion. While apparently not uncommon on Niue, currently it possibly has the smallest known distribution of any laemophloeid, being restricted as far as is known to an isolated island of only 260 km 2. It is the only laemophloeid I have seen from Niue.

Figures

Figure 3. Rhinolaemus niueensis Thomas, n. sp., female, dorsal habitus.

Figures 5–8. Rhinolaemus spp., head and pronotum. 5) R. maculatus, female holotype. 6) R. maculatus, male. 7) R. niueensis, female. 8) R. niueensis, male.

Figures 12–15. Rhinolaemus niueensis, SEM photomicrographs. 12) Head, dorsal. 13) Puncturation of head. 14) Antennal club antennomeres. 15) Elytra.

Figures 16–19. Rhinolaemus niueensis, SEM photomicrographs. 16) Head, ventral. 17) Mesocoxa. 18) Pro- and mesosternum. 19) Metasternum and abdomen.

Figures 24–27. Rhinolaemus niueensis. 24) Pronotum, SEM photomicrograph. 25) Abdominal segment VII. 26) Male genitalia. 27) Parameres and apex of median lobe.