Planetella aestivalis Ševčík & Hippa, 2023

Ševčík, Jan, Hippa, Heikki, Burdíková, Nikola, Sopuch, Kryštof, Skuhravá, Marcela & Bruun, Hans Henrik, 2023, Integrative taxonomy of Central European Planetella (Diptera: Cecidomyiidae) indicates high species diversity, intraspecific variation and low host specificity, Acta Entomologica Musei Nationalis Pragae 63 (2), pp. 413-450 : 425-427

Planetella aestivalis Ševčík & Hippa sp. nov.

( Figs 6E, 6F , 13D )

Type material. HOLOTYPE: J, Slovakia , Cerová vrchovina Protected Landscape Area, Tachty, 28.viii.–25.ix.2019, Malaise trap in Carex acutiformis , leg. J. Roháček & J. Ševčík, specimen after DNA extraction, prepared on slide, No. PLA27 a (coll. NMPC) . PARATYPEs: SLOVAKIA: 1 J 2 ♀♀, the same data as holotype, specimens after DNA extraction, one ♀ prepared on slide (No. PLA 27b, PLA 28b) (coll. JSL-UOC and SMOC); 1 J, the same data as holotype except 20.viii.–16.ix.2021, specimen after DNA extraction (No. PLA 43) (coll. JSL-UOC); 8JJ 25♀♀, the same data, in ethanol (coll. JSL-UOC); Cerová vrchovina Protected Landscape Area, Fenek Nature Monument, 19.vii.–17.viii.2022, Malaise trap in Carex acutiformis , 1J 1♀ (specimens after DNA extraction, No. PLA 55, PLA 55b), leg. J. Roháček & J. Ševčík (coll. JSL-UOC).

Additional material examined. CZECH REPUBLIC: Píšť, near pond, 2.viii.–4.ix.2023, emergence trap in Carex acutiformis , 3 JJ 1 ♀ (specimens after DNA extraction, No. PLA 75, PLA 76, PLA 76b, PLA 77), leg. J. Roháček & J. Ševčík, in ethanol (coll. JSL-UOC).

DNA sequences. DNA sequences (COI barcode region, 28S, 16S) taken from the holotype (No. PLA 27a) are deposited in GenBank. Their Accession numbers are provided in Table 1.

Diagnosis. A large, mostly light brown species, with some parts of thorax dark. Antenna with 12 binodose, relatively long flagellomeres, plus a short apical segment. Eyes with a distinct eye-bridge, at least 2 ommatidia broad (see section Variation below). Terminalia ( Figs 6E,F ) with aedeagus longer than gonocoxite, hypoproct apically almost straight, much shorter than aedeagus, and narrow pointed gonostylus.

Etymology. The name of this species refers to its late occurrence in the season (from the Latin aestas = summer); adjective.

Description. Male. Wing length 6.7 mm (paratype in ethanol). Overall body coloration mostly orange brown to greyish brown, with head, antennae, legs, halters, ventral part of abdomen and gonostyli darker.

Head. Eyes with a broad eye-bridge formed by ommatidia (4-6 ommatidia broad). Antennal flagellum with 12 binodal tricircumfilial, relatively long flagellomeres, and apically with a very short (about one third of previous flagellomere) uninodal flagellomere lacking circumfila. Flagellomere 1 ( Fig. 13D ) 4.2 times as long as broad, of similar shape as the other flagellomeres, flagellomere 4 ( Fig. 13D ) about 4.7 times as long as broad. Maxillary palpus with 3 palpomeres, P1 and P2 short, P3 almost twice as long as P2.

Thorax mostly light brown. Scutum distinctly produced above the head, with three longitudinal stripes. Posterior half of mediotergite blackish brown. Lateral sclerites mostly greyish brown.

Wing elongated, about 2.6 times as long as broad (paratype in ethanol). Veins C, R 1, R 5 and Cu-stem dark and distinct. R 1 joining C in the middle of wing. R 5 reaching C beyond wing apex. Rs indistinct. M 4 light and indistinct. CuA with dark stem and bent downwards.

Legs with tarsal claws slightly longer than maximum tarsal diameter, only moderately bent, almost straight.

Abdomen mostly light brown, ventrally darker. Tergites 2 to 7 with 2 to 3 light oval spots on each side.

Terminalia ( Figs 6E,F ). Gonocoxite relatively narrow, about four times as long as broad, mediobasally with a distinct lobe. Gonostylus narrow, slightly curved, 4.5 times as long as broad, shorter than gonocoxite, apically rounded and pointed medially. Cerci relatively small and short, rounded, basally fused. Hypoproct about twice as long as cerci, almost straight apically, only slightly excavated, with several longer marginal setae. Aedeagus narrow, slightly longer than gonocoxite, distinctly longer than hypoproct.

Female (associated with holotype male by COI sequence). Similar to male but darker, with robust abdomen and legs. Antennae shorter and thinner than in male, about 1.5 times as long as thorax. Flagellum with 12 binodose flagellomeres (plus a short apical segment), similar in shape to male but slightly less constricted. Eyes with a distinct eye-bridge, 3 or 4 ommatidia broad. Abdomen rounded, not distinctly pointed, with light oval spots on tergites 2 to 7. Cercus one-segmented, oval in shape, about twice as long as broad.

Variation. The breadth of the eye-bridge is variable among the specimens studied, spanning from 2 to 6 ommatidia. According to DNA sequences, two distinct forms can be distinguished. The more common one, which is here described as Planetella aestivalis sp. nov., and the second one, undescribed, differing 3% in COI barcode sequence, hitherto known only from a single locality in the Czech Republic (listed here as ‘Additional material’). The latter form can be considered as a separate species, although we have not yet found reliable differences in the structure of the male terminalia, except the slightly different shape of hypoproct, which appears as rounded apically, not excavated, and cerci more pointed, rather than rounded.

Biology. This species is associated with Carex acutiformis . The galls remain unknown.

Discussion. This species is currently known only from two localities in Slovakia and one in the Czech Republic. The closest species to P. aestivalis sp. nov., in terms of K2P distance ( Tab. 3), is P. attilai sp. nov., with 13.0% distance, and P. submontana sp. nov., with 14.2% distance, indicating its relatively high genetic isolation from the other species of the genus. In the phylogenetic tree ( Fig. 15), these three species form a monophyletic group with 100% support, together with Planetella sp. D , an unrecognized species from Slovakia (see below).

Figures

Fig. 6. Male terminalia in ventral (A, C, E) and dorsal (B, D, F) view. A, B (specimen No. PLA62) and C, D (holotype, No. PLA61) – Planetella adami Ševčík & Hippa sp. nov. E, F – P. aestivalis Ševčík & Hippa sp. nov. (holotype). Scale 0.1 mm.

Fig. 13. Antennal flagellomere 4 (except flagellomere 3 in H) and outline of flagellomere 1 with or without associated pedicellus and scapus. A – Planetella granifex (Kieffer, 1898), B – P.gallarum (Rübsaamen, 1899), C – P.fasciata (Meigen, 1818), D – P. aestivalis Ševčík & Hippa sp. nov.(holotype), E, F – P. adami Ševčík & Hippa sp. nov. (holotype), G – P. antennata Ševčík & Hippa sp. nov. (holotype); H – P. atrobrunnea Ševčík & Hippa sp. nov. (holotype); I – P. csabai Ševčík & Hippa sp. nov. (holotype). Scales: 0.1 mm.