Mexico lawrencei, Liu & Jia, 2021
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publication ID |
https://doi.org/ 10.1080/00222933.2021.1931516 |
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persistent identifier |
https://treatment.plazi.org/id/03F487FC-F703-7624-90B3-FEDEFC9626A7 |
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treatment provided by |
Plazi |
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scientific name |
Mexico lawrencei |
| status |
sp. nov. |
Mexico lawrencei sp. nov.
( Figures 1 View Figure 1 (c–d), 3, 4)
Etymology
The new species is named after John Lawrence, a coleopterist who collected these specimens from Christmas Island.
Type locality
Christmas Island, Australia.
Type material
Holotype. ♂, Christmas Island, 10.31S 105.37E nr. The Blowholes 12–24 April 1989. J.F. Lawrence /mud beneath limestones pinnacles ( ANIC) GoogleMaps . Paratypes: 9 specimens, with the same labels ( ANIC).
Diagnosis
This species is similar to M. papuanus, M. litoralis, M. borneensis and M. baliensis in terms of the very simple median lobe without divided subapical projections. It can be easily distinguished from those species by median lobe distinctly expanded subapically. It can be further distinguished from M. papuanus and M. litoralis by the long apical setae on the lateral lobes and lateral lobes being shorter than half of median lobe, and from M. borneensis and M. baliensis by the more acuminate apex.
Description
Colour and form. Body ( Figure 1 View Figure 1 (c,d)) small-sized, broadly elliptical, length 1.9–2.1 mm, width 1.0– 1.1 mm. Dorsal side black, covered with short, dense golden and whitish setae; ventral side more or less brownish.
Head ( Figures 1 View Figure 1 (d), 4(g)) strongly hypognathous, with mouthparts mostly concealed by labrum and prosternum when retracted, surface with dense microsculptures, occipital incisions absent; genal areas with distinct antennal grooves, margined by distinct carinae both anteriorly and posteriorly, with anterior half glabrous and posterior half microsculptured; frontoclypeal suture well developed and straight, clypeus rectangular and slightly protruding. Eyes anterolaterally located, large and finely faceted, well separated. Antennal insertions exposed, well separated from eyes. Antennae ( Figure 4 View Figure 4 (f)) 11-segmented, with 4-segmented club; scape and pedicel enlarged, antennomere 3 stout, antennomeres 4–7 narrow, last segment subulate. Labrum large and sub-trapezoid, wider than long. Mandibles ( Figure 4 View Figure 4 (d)) small and sub-triangular, dorsal side distinctly elevated, apex slender; inner edge membranous, with a membranous apical projection; mola well developed. Maxilla ( Figure 4 View Figure 4 (e)) slender, with 4-segmented palps, last segment enlarged and acuminate apically; lacinia elongated with apical hook and short subapical spine; galea subequal in length with lacinia, apex acuminate. Labium ( Figure 4 View Figure 4 (c)) with 3-segmented labial palps, second segment enlarged, last segment small; ligula well developed. Mentum rectangular, longer than wide. Gular area highly reduced. Cervical sclerites present and large.
Thorax. Pronotum transverse, about 0.4 times as long as wide, widest posteriorly; lateral margins slightly curved, posterior margin sinuate with distinct median lobe; anterior angles broadly acute and forwardly projecting; disc weakly convex, with dense microsculptures. Pronotal epipleuron broad and slightly depressed. Prosternum narrow, prosternal process broad and parallel-sided. Notosternal suture complete. Procoxae strongly transverse, protrochantins small and exposed; procoxal cavities well separated, with small anterolateral incisions, externally broadly opened and internally narrowly opened. Scutellum small and triangular. Elytra about 1.4 times as long as wide, with about 10 tiny teeth along anterolateral edges and one small apical projection on either side; disc slightly convex, with dense microsculptures; epipleuron broad at base, extending to apical projection. Hing wings well developed. Mesoventrite ( Figure 4 View Figure 4 (a)) shortened, with large median concavity fitting to prosternal process. Mesanepisternum and mesepimeron fused ( Figure 4 View Figure 4 (a)). Metaventrite subtriangular, strongly transverse at base, with deep and narrow apical incision; metendosternite with basal strut highly sclerotised, large and fusiform, fused with metaventrite by transverse carinae; lateral arms relatively long, with complicated ventral projections connected with apex of basal strut; metanepisternum highly reduced, partly exposed from ventral side which is triangular. Mesocoxae ( Figure 4 View Figure 4 (a)) slightly transverse, trochantins exposed; mesocoxal cavities widely separated, laterally open to mesepimeron. Metacoxae large and transverse, strongly oblique, narrowly separated; metacoxal plates large, sharply narrowed to lateral edges. Legs with femora slightly enlarged, tibiae slender, tarsi slightly shorter than tibiae, claws small; tarsal formula 4-4-4, basal three tarsomeres with pair of short apical spines. Hind leg distinctly longer than others, tibiae with long spines along outer edges.
Abdomen ( Figure 4 View Figure 4 (b)) 5-segmented with basal three ventrites connate, lateral edges expanded with narrow flanges.Ventrite 1nearly divided by metacoxae,with intercoxal process short and acute; ventrites 2–4 sub-equal in length; last ventrite elongate and subtriangular, with pair of small posterolateral projections, bearing clustered sub-lateral long setae.
Male genitalia with tergite VIII as in Figure 4 View Figure 4 (h). Aedeagus ( Figure 4 View Figure 4 (i)) with lateral lobes about half length of penis, bearing two long apical setae; basal piece sub-annular; median lobe elongate and simple, slightly constricted at about middle, apex acuminate. Female genitalia with spiculum ventrale ( Figure 4 View Figure 4 (k)) elongated and bifurcate; ovipositor ( Figure 4 View Figure 4 (j)) heavily sclerotised, without stylus, baculus extremely long; spermatheca well sclerotised.
Sexual dimorphism not distinct, ventral side of apical tibiae and basal tarsomeres of fore legs with denser setae in male.
Habitats
Living in mud under seaside reefs.
Key to species of Mexico Spilman View in CoL from the Oriental region, derived from Yoshitomi (2019)
1. Median lobe with distinct subapical projections laterally, separated from ventral part....................... ......................................................................................................... 2
- Median lobe simple, without subapical projections laterally.......................6
2. Subapical projections of median lobe distinctly curved outwardly.................. 3
- Subapical projections of median lobe curved interiorly or ventrally................ 4
3. Subapical projections of median lobe nearly equal in length, apex of median lobe slender and gradually acuminate; Palau....................... ......... M. palauensis
- Subapical projections of median lobe with left part distinctly longer than right, apex of median lobe robust and sharply acuminate; Yongxing Island.......... ... M. xiei
4. Subapical projections of median lobe of same length, ventrally curved; apex of median lobe slender; Ogasawara Island.................. ......... M. ogasawaraensis
- Subapical projections of median lobe with left part distinctly longer than right, interiorly curved; apex of median lobe robust.......................................5
5. Subapical projections of median lobe short and small, widely separated from each other; Taiwan...... ..................................................................................................... M. taiwanus
- Subapical projections of median lobe large, nearly attached to each other at middle; Honshu to Ishigakijima.......................... .................... ................... M. masamii
6. Lateral lobes long, exceeding proximal half of median lobe, apex of lateral lobes with short setae; Papua New Guinea..................... ............................... M. papuanus
- Lateral lobes shorter than half of median lobe, apex with long setae...............7
7. Median lobe distinctly expanded subapically; Christmas Island........... .................. .............................................................................................................................................. M. lawrencei
- Median lobe not distinctly expanded subapically...................................8
8. Apex of median lobe nipple-like; Borneo........................... M. borneensis
- Apex of median lobe simply pointed; Bali......................... ... .. M. baliensis
| ANIC |
Australian National Insect Collection |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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