Latonius planus Kononova, 1982

Vasilița, Cristina, Popovici, Ovidiu Alin, Talamas, Elijah, Johnson, Norman, Masner, Lubomir, Tortorici, Francesco & Fusu, Lucian, 2021, Molecular analysis reveals Latonius planus Kononova to be a derived species of Trissolcus Ashmead, Journal of Hymenoptera Research 87, pp. 267-289 : 267

Latonius planus Kononova, 1982

Diagnosis.

Antennal clava not distinctly wider than preceding flagellomeres; pretarsus enlarged with well-developed arolium; genal striae absent; maxillary palpus 1-segmented; subacropleural and prespecular sulci absent; mesoscutellar sculpture absent; metascutellum enlarged and smooth; body obviously dorsoventrally flattened.

Description.

Female body length: 0.85-1.03 mm (n = 3). Body color: dark brown to black (Figures 10 , 11 ).

Head. Color of radicle: brown. Length of radicle: less than width of clypeus. Color of A1-A6 in female: light brown to brown. Color of A7-A11 in female: brown. Clava: undifferentiated from preceding antennomeres. Ratio between width of 1st clavomere (A8) and A7: 1-1.1. Number of papillary sensilla on A7: 0. Claval formula: 1-1-1-1 (A8-A11) (Figure 5 ). Facial striae: absent. Number of clypeal setae: 6 (Figure 7 ). Number of mandibular teeth: 3. Size of mandibular teeth: the median tooth smallest, hardly visible (Figure 7 ). Microsculpture on gena directly above mandibular condyle: reticulate coriaceous. Shape of gena in lateral view: approximately the same width from vicinity of lower eye margin to above mandibular condyle. Genal carina: present and extending dorsally to vicinity of lower eye margin. Malar striae: absent. Sculpture of malar sulcus: faintly present. Orbital furrow: uniform in width between midpoint of eye and malar sulcus (Figure 8 ). Macrosculpture of frons between antennal scrobe and anterior ocellus: absent or faintly coriaceous. Preocellar pit: present, located within ocellar fovea. Setation of lateral frons: two rows of few (4-5) setae along the inner orbit and another few setae (4-6) on the dorsal half of lateral frons. Punctation of lateral frons: absent. Sculpture directly ventral to preocellar pit: present. Macrosculpture of lateral frons: well-defined coriaceous near antennal scrobe to imbricate coriaceous near the inner orbit (Figure 7 ). OOL: more than two times ocellar diameter. Hyperoccipital carina: absent. Anterior margin of occipital carina: crenulate (Figure 3 ).

Maxillolabial complex (Figure 6 ). Sculpture of posterior stipital sclerite: absent. Campaniform sensillum on 1st maxillary palpomere: absent. Trichoid sensilla on 1st maxillary palpomere: present apically. Number of maxillary palpomeres: 1. Lacinia: concealed. Mesal side of basal galeal sclerite: straight. Setae on apical edge of basal galeal sclerite: present. Lateral galeal crease: absent. Interstipital sclerite: absent. Lateral faces of prementum: not continuous posteriorly. Premental carinae: strip-like. Number of labial palpomeres: 1.

Mesosoma. Mesosoma: visibly depressed (two times as wide as high). Mesoscutum, mesoscutellum and metascutellum: in the same plane. Epomial carina: present. Macrosculpture of lateral pronotum directly anterior to netrion: coriaceous. Netrion sulcus: complete. Pronotal suprahumeral sulcus: hardly visible, faintly crenulated or undifferentiated from sculpture of dorsal pronotum (Figure 4 ). Number of episternal foveae: 3. Acropleural sulcus: present, developed. Subalar pit: present. Subacropleural sulcus: absent. Speculum: transversely strigose. Mesopleural pit: present, circular, not prolonged into a furrow. Mesopleural carina: absent. Sculpture of femoral depression: smooth. Patch of striae at posteroventral end of femoral depression: absent. Setal patch at posteroventral end of femoral depression: absent. Microsculpture of anteroventral mesopleuron: absent. Macrosculpture of anteroventral mesopleuron: imbricate coriaceous. Postacetabular sulcus: present as a furrow with no cells or crenulae. Setation of posteroventral metapleuron: absent. Sculpture of dorsal metapleural area: absent. Mesepimeral sulcus: present, weakly indicated, smooth. Posterodorsal metapleural sulcus: hardly visible, as a smooth line of foveae. Paracoxal sulcus in ventral half of metapleuron: absent. Anteroventral extension of metapleuron: not extending to base of mesocoxa. Metapleural epicoxal sulcus: present as coarse rugae (Figures 9 , 11 ). Mesoscutal humeral sulcus: indicated by a narrow furrow. Median mesoscutal line: absent. Macrosculpture of mesoscutum: coriaceous. Mesoscutal suprahumeral sulcus: not visible. Parapsidal line: absent. Notaulus: absent. Median protuberance on anterior margin of mesoscutellum: absent. Shape of dorsal margin of anterior lobe of axillar crescent: rounded. Sculpture of anterior lobe of axillar crescent: oblique strigose. Posterodorsal margin of axillular carina: rounded. Macrosculpture of mesoscutellum: absent. Mesoscutellum: 3.4 × as wide as long. Length of mesoscutellum / length of metascutellum: mesoscutellum 1.9 × as long as metascutellum. Microsculpture on mesoscutellum: absent. Setation of posterior mesoscutellar sulcus: present. Form of metascutellum: transverse plate, 4.8 × as wide as long. Metanotal trough: foveate, with a row of small foveae intercalated between two smooth areas. Metapostnotum: invaginated near lateral edge of metascutellum (Figures 3 , 10 ). Length of postmarginal vein: around twice as long as stigmal vein. Basal vein: indicated as pigmented nebulous vein (Figures 12 , 13 ). Color of legs: coxae dark brown to black, femora light to dark brown, and brown elsewhere (Figures 10 , 11 ). Pretarsus: modified with atrophied claws, each bearing a long seta and hypertrophied arolium. Shape of arolium: rhomboidal (Figures 14 , 15 ). Protarsus: 5th tarsomere as long as 4th and 3rd tarsomeres together, 1.6 × as wide as 4th tarsomere and as wide as pretarsus.

Metasoma (Figure 16 ). Number of tergites: 7. Number of sternites: 6. Laterotergites: wide. Laterosternites: absent. Longitudinal striae on T1 posterior to basal costae: present on anterior 2/3. Number of sublateral setae (on one side): 2. Setation of laterotergite 1: one seta. Longitudinal striation of T2: faintly present anteriorly. Setation of T2: present (4 setae). Setation of laterotergite 2: present. Posteriorly directed setae on medial S1: absent (Figures 3 , 10 ).

Ovipositor (Figure 17 ). Ovipositor system: Ceratobaeus -type. Proximal part of ventral membranous plate: present. Proximal arm: large, long and wide, 0.6 × as long as third valvula. First valvifer: large, longest diameter 1.2 × as long as width of proximal arm at the proximal end. Second valvula: simple. Third valvula: elongated, broad and heavily sclerotized distally, 0.4 × as long as length of ovipositor. Lateral apodemes: present. Medial apodeme on S6: present.

Material examined.

Holotype of Latonius planus : Ukraine: 1♀, “Запорожск, г. Приморский, коса Обиточная, С. Кононова [Zaporizhzhia Oblast, Primors’kyi city, Obitochnaya bank, S. Kononova leg.], 27.VI.1979 " . Holotype of Ioseppinella serena : Italy: 1♂, " Sicilia, 21.X.1980, Santa Flavia, Cefala, y. trap [yellow trap in a citrus lemon orchard], A. Mineo leg.", UNIPA-HYM-S01331. Non type material: France: 5♀; Gard dep., Liouc ; 43.89007N, 3.97897E; 135 m alt.; 5.IX.2018; glades in Quercus forest; screen sweeping; Fusu L. & Mitroiu M. leg.; Spain: 1♀ (specimen examined by L. Masner, but label data not available, CNC being closed due to the COVID pandemic) .

Variability.

Although most specimens of Latonius used in this study are from the same locality and likely belong to the same population, we found some morphological variation that does not appear to be size related: the genal carina is always present, but it can be well developed or faintly defined. The macrosculpture of the frons between the antennal scrobe and anterior ocellus can be well-defined or smooth, almost absent. The hyperoccipital carina is almost certainly absent, but in a specimen with the most evident sculpture, it can be imagined as an outline. The antero-admedian lines can be observed in two specimens but are absent in the other three. The femoral depression may be smooth or faintly striate. The postacetabular sulcus is present as a few superficial cells in only one specimen. The macrosculpture on the mesoscutum was observed to be coriaceous laterally but smooth centrally (internotaular area) and adjacent to the transscutal articulation in one specimen.

Figures

Figures 10 - 17. Trissolcus planus (female) 10 habitus, dorsal view 11 habitus, lateral view 12 fore and hind wings 13 fore wings venation 14, 15 arolium 16 metasoma with exposed tergites, sternites and latero-tergites (composite image) 17 ovipositor assembly (composite image).

Figures 3 - 9. Trissolcus planus (female) 3 habitus, dorsal view (SEM) 4 habitus, lateral view (SEM) 5 female antenna 6 maxillolabial complex (composite drawing) 7 head, frontal view (SEM) 8 head, lateral view (SEM) 9 mesosoma, lateral view (SEM).