Hamma spinellii, Durante & Loudit & Susini, 2021

Durante, Antonio, Loudit, Sandrine Mariella Bayendi & Susini, Antonio, 2021, On the genus Hamma Buckton, 1905 (Hemiptera: Auchenorrhyncha) in Equatorial Africa, with descriptions of three new species, European Journal of Taxonomy 748 (1), pp. 89-107 : 97-98

Hamma spinellii sp. nov.

urn:lsid:zoobank.org:act:C19025BA-2C70-4CD0-BF61-68ED3716A5E0

Figs 2 , 4C , 5C

Diagnosis

Species belonging to the genus Hamma with thorax eminently brown, pronotum smooth and metopidium not densely tuberculate; suprahumeral horns with a laterally pointing thorn; a posterior process with four nodes, V-shaped in lateral view between the second and fourth nodes; last node roundish in dorsal view, ending in a well-developed terminal spine. Pterostigma almost three times longer than broad.

Differential diagnosis

The general light brown colour is diagnostic, heimi and nigrum sp. nov. being black, and caneparii sp. nov. having a mosaic of russet brown and black.

Other diagnostic characters with respect to caneparii sp. nov. are:

– the similarity of the width and height of the basal element of the suprahumeral horns (frontal view) ( Fig. 4C ): in spinellii sp. nov. the w/h ratio is 1; in caneparii sp. nov. the w/h ratio is 0.66;

– caudal node of the posterior process half the width of the head in spinellii sp. nov.; ⅔ the width in caneparii sp. nov. (dorsal view);

– anchor-like third node ( Fig. 5C ) thinner than in caneparii sp. nov. (dorsal view);

– length of the posterior process clearly exceeding abdominal length in spinellii sp. nov.; not exceeding the abdominal terminalia in caneparii sp. nov. (lateral view);

– pterostigma ( Fig. 5C ) longer in spinellii sp. nov.: l/w ratio 3.4 in spinellii sp. nov.; 2.4 in caneparii sp. nov.

Other diagnostic characters with respect to heimi and nigrum sp. nov. include:

– upper margin of the head roughly square ( Fig. 4C );

– metopidium ( Fig. 4C ) tuberculate;

– suprahumeral horns ( Fig. 4C ) with a robust straight thorn, not curving upwards in frontal view;

– anchor-like third node ( Fig. 5C ) posteriorly prolonged (dorsal view); rhomboidal or roughly circular in nigrum sp. nov. and heimi .

Etymology

The species is dedicated to Dr Matteo Spinelli, Milano.

Material examined

Holotype GABON • ♀; Ogooué Ivindo , Mont Sassamongo , Batouala ; 30 Nov. 2012; A. Susini leg.; MSNS.

Description

MEASUREMENTS. Holotype total length: 3.8 mm; pronotal length: 4.4 mm; tegminal length: 4.3 mm.

HEAD. Black with brown suffusion along the margins and at the centre, convex, punctate, with small white setae; vertex width one and a half times the height; shallow concavity between the ocelli; carina present; upper margin arcuate but roughly square with two evident corners, one directly above each ocellus; ventral margin W-shaped with the lower parts not very pronounced; ocelli slightly above the centro-ocular line. Frontoclypeus pear-shaped, lateral lobes completely fused to frontoclypeus with margins barely distinguishable; rostrum and antennae light brown.

PRONOTUM. Light brown with one triangular black patch on the metopidium on each side of the carina, punctate, almost completely naked; metopidium tuberculate in its dorsal region, twice as wide as high, median carina percurrent, unpunctate, straight, with some swelling, supraocular callosities bean-like, slightly or not at all punctate, with a small club-shaped darker formation inside them, shallow and very finely punctate; humeral angles prominent and blunt; suprahumeral horns well developed, with a tower-shaped base, tuberculate, with a robust brown and black-tipped thorn pointing laterally? Posterior process light brown, punctate, emerging posteriorly from the pronotum and continuously from the posterior margin; sinuate in lateral view, with four nodes, the first of which (proximal) almost spherical; second node small, dome-shaped in lateral view (flattened in dorsal view) with seven-eight small spines latero-dorsally; third node anchor-like in dorsal view with one (left) or two (right) small spines at the end of the lateral arms; fourth node subspherical, almost one and a half times larger than the first, with many spines and a robust terminal spine at the caudal end; dorsal and ventral carinae continuous, of the same colour. A few spines along the dorsal carina, and dorsally and ventrally along the trunk of the posterior process between the third and fourth nodes. Each spine bears a very thin light apical seta.

SCUTELLUM ( Fig. 5 ). Entirely brown, punctate, with the base longer than the height, emarginate with scutellar apices acute with a few translucent setae; base with a triangular swelling except at the corners; lateral corners of the swelling with a tuft of small shiny ochraceous setae.

FOREWING. Length about two and a half times width (l/w ratio 2.56), hyaline; basally sclerotized, punctate, grey-brown in colour with three to four brown stripes distally. Pterostigma sub-triangular with very rounded corners, blackish in colour; venation grey-brown; large brown shaded trapezoidal patch extending from costa to inner margin in the median area; I-shaped patch extending from costa to anal angle with light grey-brown anterior half and dark grey-brown posterior half.

LEGS. Ochreous yellow, praetarsi brown.

ABDOMEN. Tergites grey-brown with black punctation and lighter caudal borders; sternites brown, as are the borders, and covered in translucent setae.

Figures

Fig. 2. Hamma spinellii sp. nov., holotype, ♀, Gabon, Ogouè Ivindo, Mont Sassamongou, Batouala, 30 Nov. 2012, A. Susini leg. (MSNS).

Fig. 4. Morphology. Left suprahumeral horn and left supraocular callosity, frontal view. A. Hamma heimi Boulard, 1968. B. Hamma nigrum sp. nov. C. Hamma spinellii sp. nov. D. Hamma caneparii sp. nov. Figures are not to scale.

Fig. 5. Morphology. Pterostigma of right wing in dorsal view; third node of the posterior process in dorsal view; scutellum in lateral right view. A. Hamma heimi Boulard, 1968. B. Hamma nigrum sp. nov. C. Hamma spinellii sp. nov. D. Hamma caneparii sp. nov. Figures are not to scale.