Melanophilharmostes gillesi, Ballerio & Coache, 2023

Melanophilharmostes gillesi View in CoL sp. nov.

( Fig. 1 - 3)

ZooBank:https://zoobank.org/ 4D054B4D-D13B-4726-91C9-569471BDB50F

Holotype, ♂, deposited in the collection of MHNL, Lyon , France, labelled as follows: / Sao Tome et Principe, Ile de Sao Tome, 28 m, Ponta Furada, 06 XI 2022, Microland Expe 5, Leg. B. Gilles, battage / Melanophilharmostes gillesi n. sp. det. A. Ballerio & A. Coache, 2023 Holotypus ♂ / [specimen glued on a card, male genitalia glued on a separate card pinned beneath the specimen].

Diagnosis. – Melanophilharmostes gillesi sp. nov., can be differentiated from the other species of the genus by the following combination of characters:

a) dorsal body surface without uniform cover by dense fine punctation (sensu Ballerio, 2016) (only few very sparse punctures are present);

b) head punctation made of transverse short comma-shaped punctures; c) pronotum with larger punctation made of wide comma-shaped punctures;

d) pronotum without transversal long shallow lines;

e) elytra without longitudinal rows of fine lines or punctures;

f) elytral carina delimiting epipleuron present and complete;

g) elytral punctation mainly made of transverse large comma-shaped punctures;

h) aedeagus with short parameres (length ratio of parameres to phallobasis = 0.4);

i) brachypterous.

Because of the lack of uniform cover of dense fine punctation on elytra, M. gillesi sp. nov. can be compared only to M. ashantii (Paulian, 1974) from Ghana, M. bicarinatus (Paulian, 1974) from Ghana, M. burgeoni (Paulian, 1946) from Ivory Coast, Congo, Cameroon, and Angola, M. donisi (Basilevsky, 1955) from Congo, M. endroedyi (Paulian, 1968) from Congo, M. ocellatus (Paulian, 1968) from Congo, and M. pygmaeus (Petrovitz, 1968) from Congo. The new species, lacking ocellate punctation on pronotum, can be easily differentiated from M. bicarinatus, M. burgeoni, M. donisi, and M. ocellatus. It differs from these species also because of the complete elytral carina delimiting the pseudoepipleuron, which in all the above listed species is limited to the median- and distal-third of the elytron.The differences with M. ashantii and M. endroedyi lie in the lack, in M. gillesi sp. nov. of any longitudinal lines on elytra and again in the development of the elytral carina delimiting the pseudoepipleuron, which in M. ashantii and M. endroedyi is limited to median- and distal-third of the elytron.

Description of the holotype

Dimensions. –HL: 1.0 mm; HW: 1.5 mm; PL: 1.5 mm; PW: 2.7 mm;

EL: 3.0 mm; EW: 2.8 mm.

General aspect. – Small sized flightless Ceratocanthinae . Body moderately convex. Brown, shiny, dorsum with setigerous punctures bearing a relatively long erect feebly clavate seta (40×), underside, tarsi and antennae reddish-brown, setation yellowish.

Head. – W/L ratio = 1.44; apical margin triangular with angle obtuse and sharp and sides weakly curved; genae distinctly produced outwards, acute; genal canthus complete, fused with the occipital portion of head; dorsal ocular area medium-sized, interocular distance about 13 times the maximum width of dorsal ocular area, ventral ocular area large, clypeal surface covered by strongly impressed medium-sized transverse comma-shaped punctures, oriented centrifugally and mixed to few simple fine punctures bearing an erect medium-sized fine seta, punctation sparser on clypeal disc, vertex having a transverse furrow, shortly interrupted in the middle. Interpunctural distance of comma-shaped punctures shorter than punctural diameter; fore margin with some transverse large comma-shaped punctures. Antennae with ten antennomeres.

Pronotum. – Transverse (W/L ratio = 2.25), subtrapezoidal, weakly convex, surface regular, fore angles not truncate, the whole pronotal margins marked by a continuous circumnotal ridge; whole pronotal surface covered by shallow punctation: punctation on disc made of transverse lines of variable length mixed with very few simple fine punctures and with two smooth areas in the middle of disc and near pronotal base, punctation on sides made of denser large comma-shaped punctures with opening oriented outwards; interpunctural distance shorter than punctural diameter. Setation long and erect.

Scutellum . – Covered by several small transverse comma-shaped punctures, interpunctural distance inferior than punctural diameter.

Elytra. – Longer than wide (W/L ratio = 0.92); subovoidal (dorsal view); humeral callus indistinct; elytral surface convex, covered by sparse (interpunctural distance equal to or twice than punctural diameter) shallow punctation. Punctation made of large horseshoeshaped punctures with opening directed backwards mixed to fewer comma-shaped punctures mainly concentrated on elytral basal third. Horeseshsoe-shaped and comma-shaped punctures having a simple setigerous pore inside, setae relatively long and fine, distally clavate. Lateral carina distinct, thick, sharp and complete. Pseudoepipleura covered by few large comma-shaped punctures with opening directed upwards.

Wings. – Brachypterous.

Sexual dimorphism. – Unknown due to the lack of available females. The male holotype displays the usual secondary sexual dimorphism found in other species of Melanophilharmostes , i.e., male protibiae with short apical teeth and mesotibial inner apical spur bent inwards at a right angle.

Male genitalia. – Aedeagus with short distally membranous subtruncate parameres, as in Fig. 3a-c; spiculum gastrale as in Fig. 2.

Etymology. – Noun in the genitive case. Named after Benoit Gilles (Angoulème, France), who collected the holotype.

Distribution and habitat. – Known only from the type locality ( Fig. 5 -6), in the northwestern portion of the island of São Tomé ( República Democrática de São Tomé e Príncipe) (0°14’17’’N - 6°28’24’’E). The area is characterized by a large secondary moist forest. The holotype was observed walking on leaves at night ( Fig. 4).

Remarks. – This is the second Ceratocanthinae known to occur on São Tomé island after the recently described Chaetophilharmostes filippii Ballerio&Coache,2022 .The onlyother Melanophilharmostes known to occur in the Guinea Gulf islands is Melanophilharmostes poggii Ballerio, 2016 from Annobón / Pagalu island (Ballerio, 2016). Melanophilharmostes gillesi sp. nov. is brachypterous. An extensive study of wing development in the genus is not available. To our knowledge at least one other species of Melanophilharmostes is flightless, i.e., the aforementioned M. poggii (also brachypterous) and again from a small oceanic island.