Hadronotus pubescens (Motcshoulsky)

Raju, Md. Rasel, Arifunnahar, Mst., Mostafiz, Md. Munir, Alim, Md. Abdul, Hossain, Md. Alamgir & Talamas, Elijah J., 2022, Hadronotus pubescens (Motschoulsky) (Hymenoptera, Scelionidae): Redescription, biological attributes, and parasitism on eggs of Riptortus pedestris (Fab.) (Hemiptera, Alydidae), Journal of Hymenoptera Research 94, pp. 139-161 : 139

Hadronotus pubescens (Motcshoulsky)

Figs 1-3 , 4-6 , 7-11

Muscidea pubescens Motschoulsky, 1863: 70 (original description).

Gryon pubescens (Motschoulsky): Masner 1976: 57 (generic transfer, type information); Johnson 1992: 395 (cataloged, type information).

Gryon hogenakalensis Sharma, 1982: 329, 336 (original description, keyed); Lê, 1997: 23 (keyed); Lê, 2000: 99, 118 (description, keyed, type information).

Gryon hogenakalense Sharma: Johnson 1992: 384 (cataloged).

Hadronotus pubescens (Motchoulsky): Talamas et al. 2021: 441 (generic transfer).

Hadronotus hogenakalensis (Sharma) syn. nov.: Talamas et al. 2021: 423 (generic transfer).

Images of holotype specimens.

Muscidea pubescens : https://zenodo.org/record/4924954#.YkMH-PnMJaQ. Gryon hogenakalensis : USNMENT01197123.

Description.

Color of body: dark brown to black. Color of antenna in female: radicle black, A1-A6 yellow-brown with scape darker in middle, A7-A12 black. Color of legs: coxae and femora brown; trochanters, tibiae and tarsi yellow to pale brown. Body length of female: 1.07-1.43 mm (n = 12). Body length of male: 1.34-1.38 mm (n = 2).

Head: Claval formula: A12-A7: 1-2-2-2-2. Number of mandibular teeth: 3. Size of mandibular teeth: small, middle tooth the smallest. Shape of clypeus: transverse, not projecting ventrally, apex flat. Number of clypeal setae: 6, lateral pair very short; medial pairs approximately equal in length; Epiclypeal carina: present. Facial striae: absent. Central keel: present in lower portion of frons. Line of setae above interantennal process: absent. Sculpture of ventral frons: strigose, strigae arching slightly ventrally from central keel, sometimes extending to inner orbit. Sculpture of dorsal frons: transversely strigose medially, weakly rugulose along inner orbit of compound eye. Preocellar pit: absent. Malar striae: absent. Sculpture of gena directly above mandibles: smooth. Genal carina: absent. Occipital carina: continuous medially, with sharp corner behind dorsal apex of compound eye. Anterior margin of occipital carina on gena: crenulate. Anterior margin of occipital carina on posterior head: simple. Hyperoccipital carina: present. Marginal carina: present. Sculpture of occiput: arched, parallel rugae.

Mesosoma: Epomial carina: present. Sculpture of pronotum posterior to epomial carina: transversely rugose. Sculpture of pronotum anterior to epomial carina: smooth. Sculpture of pronotum dorsal to epomial carina: pustulate-punctate. Netrion sulcus: absent. Pronotal suprahumeral sulcus: absent. Setation of lateral pronotum: white; uniformly dense dorsal topomial carina, with small setal patch directly anterior to epomial carina. Mesoscutal suprahumeral sulcus: absent. Mesoscutal humeral sulcus: indicated by a shallow smooth furrow. Mesoscutal humeral pit: present. Sculpture of mesoscutum: reticulate-punctate, with longitudinal rugae in posteromedial portion. Setation of mesoscutum: white, mostly uniform in density, slightly sparser lateral to parapsidal line. Scutoscutellar sulcus: smooth furrow medially, striate laterally. Sculpture of mesoscutellar disc: longitudinally rugose medially, with coarse microsculpture throughout. Posterior mesoscutellar sulcus: foveate.

Posterior margin of mesoscutellum: not extending over metanotum, metascutellum visible in dorsal view. Posterior margin of metascutellum: convex. Sculpture on posteroventral surface of metascutellum: finely strigose. Sculpture of metanotal trough: foveate. Lateral propodeal area: narrow, deeply foveate with white setation. Lateral propodeal carina: extending laterally to metapleural carina, forming flange around metasomal depression. Sculpture of metasomal depression: radially rugulose. Sulcus of the propodeal foramen: foveate.

Postacetabular sulcus: crenulate. Posterior limit of acetabulum: intersecting with ventral mesopleural carina. Mesopleural epicoxal sulcus: composed of shallow foveae. Episternal foveae: absent. Mesopleural carina: present, parallel to acetabular carina. Sculpture of mesopleuron above mesopleural carina: transversely rugose. Femoral depression: not indicated. Prespecular sulcus: composed of large foveae. Sculpture of speculum: transversely rugose. Shape of subalar pit: roughly circular. Mesepimeral sulcus: foveate, foveae of uniform size. Posterior mesepimeral area: smooth, narrow. Paracoxal sulcus: foveate, absent in ventral part of metapleuron. Metapleural epicoxal sulcus: foveate. Dorsal metapleural area: smooth, with white setation posteriorly. Ventral metapleural area: irregularly rugulose, setose. Posterodorsal metapleuron sulcus: foveate, present along entirely of metapleural carina.

Wings: Length of postmarginal vein in fore wing: almost twice as long as stigmal vein. Length of marginal vein in fore wing: about one third as long as stigmal vein. Color of wing disc: hyaline. Color of fore wing setation: brown in distal half, white in basal half. Color of hind wing setation: white throughout. Shape of submarginal vein: shallowly curved, nearly parallel to wing margin, without sharp bend.

Metasoma: Basal foveae: present on T1-T2, S1-S2. Setation of T1-T3: present on lateral portions of tergite. Setation of T2-T5: dense in lateral part of tergite, absent medially except for a transverse line of sparse setae along posterior margin. Sculpture of T1: longitudinally striate, smooth along posterior margin. Sculpture of T2-T4: finely reticulate with a smooth band along posterior margin. Posterior margin of T5: concave. Setation of laterotergites: present. Sculpture of ventral metasoma: reticulate microsculpture throughout. Setation of ventral metasoma: absent from anterolateral S2, otherwise evenly setose throughout.

Intraspecific variation: The specimens examined here are phenotypically uniform, with slight variation occurring in the degree to which transverse striation is developed on the frons and how far the striation extends laterally. The specimens from Bangladesh showed little variation in size, with females ranging from 1.25-1.43 mm. The female specimen from Taiwan was significantly smaller (1.07 mm).

Material examined.

Holotype, female, Muscidea pubescens Motchoulsky : Sri Lanka: Nuwara Eliya, ZMMU 0001 (ZMMU) . Holotype, female, Gryon hogenakalensis Sharma : India: Hogenakal, 1-FEB-1977, coll. Mani, M. S., USNMENT01137123 (USNM). Bangladesh: 12 females, 2 males, DPI_FSCA 00008722, FSCA 00034113-00034118, 00034090-00034094, 00094879, 00094882 (FSCA). Taiwan: 1 female, FSCA 00094687 (FSCA) .

Comments.

Hadronotus pubescens is a widespread species, ranging at least from Sri Lanka to Taiwan based on the specimens examined here. The COI sequences from the Taiwanese and Bangladesh specimens share 99.83% sequence identity, providing strong molecular support that they are conspecific. However, a more comprehensive examination of the species limits of H. pubescens is still needed and will require analysis of specimens from an even greater geographic range. We examined specimens from South Africa that are morphologically very similar to H. pubescens in Asia, presently separable only by the color of the appendages, yet their COI sequences differ by nearly 13%.

Hadronotus pubescens belongs to a lineage, the Hadronotus pubescens species group, that Mineo (1980) defined primarily by the presence of a "marginal carina" (Figs 4 , 8 , mac), which extends medially from the hyperoccipital carina. Two characters provide evidence that this lineage is close to the charon species group: the mesoscutal humeral pit (Fig. 10 , mhp) and the epiclypeal carina (Figs 2 , 7 , ec). The mesoscutal humeral pit was first documented by Chen et al. (2020) in H. ancinla (Kozlov & Lê) and is present in all species of the charon group that we have examined. The antennal scrobe in the charon group is entirely delimited by a continuous carina. We consider the ventral, transverse portion of this carina to be homologous with the epiclypeal carina, as is found in H. pubescens . The taxon sampling in the multi-gene phylogeny presented in Fig. 2 of Talamas et al. (2021) does not allow for analysis of the monophyly or delimitation of these two species groups. The systematics of Hadronotus is ongoing and treatment of species groups within the genus is a research priority.

The metapectal propodeal complex contains morphological characters that have yet to be fully exploited in Hadronotus . Carinae and sulci on the metasomal depression vary remarkably among species that we have examined and are likely to become more informative as they are studied in greater detail. The ventral mesopleural carina delimits the posterior margin of the metapleuron on the venter and may be interrupted by the foramen of the hind coxa, as in H. pubescens (Figs 9 , 11 ). A transverse carina often extends from the propodeal foramen across the metasomal depression and may be accompanied by a sulcus (Fig. 11 ). Talamas et al. (2021) provided the term "sulcus of the propodeal foramen" for Gryon aetherium Talamas, which is present only dorsally. In H. pubescens , foveae are present ventral to the transverse carina on the metasoma depression. It is presently unclear if these foveae are a continuation of the sulcus of the propodeal foramen or an independent structure.

Figures

Figures 1 - 3. Hadronotus pubescens, female (FSCA 00094879) 1 lateral habitus 2 head, anterior view 3 wings.

Figures 4 - 6. Hadronotus pubescens, female (FSCA 00094879) 4 head, mesosoma, metasoma, dorsal view 5 head and mesosoma, lateral view 6 head, mesosoma, metasoma, posterolateral view.

Figures 7 - 11. Hadronotus pubescens, female (FSCA) 7 ventral frons, anterolateral view 8 head, posterolateral view 9 mesosoma, ventrolateral view 10 mesosoma, dorsolateral view, 11 mesosoma, posterolateral view. Scale bars in millimeters.