Trioxys ulmi Čkrkić & Tomanović, 2021

Čkrkić, Jelisaveta, Petrović, Andjeljko, Kocić, Korana & Tomanović, Željko, 2021, Insights into phylogenetic relationships between Trioxys Haliday, 1833 and Binodoxys Mackauer, 1960 (Hymenoptera, Braconidae, Aphidiinae), with a description of a new species of the genus Trioxys, Zoosystema 43 (8), pp. 145-154 : 147-151

Trioxys ulmi Čkrkić & Tomanović , n. sp.

( Figs 2 ; 3 )

urn:lsid:zoobank.org:act:A6C5F36F-5CC4-4188-A5A9-1EC300CC562B

TYPE LOCALITY. — Serbia, Belgrade, New Belgrade (44°28’47”N, 20°12’55”E).

TYPE MATERIAL. — Holotype. Serbia • 1 ♀; Belgrade, New Belgrade 44°28’47”N, 20°12’55”E; 22.VI.2017; Korana Kocić leg.; reared from T. takachihoensis on Ulmus x hollandica, slide mounted; FBUB. Paratypes. Serbia • 21 ♀, 14 ♂; same data as holotype; preserved in alcohol and slide mounted (2 ♀, 2 ♂); FBUB (17 ♀, 9 ♂); MNHN (5 ♀, 5 ♂).

DISTRIBUTION. — The current known distribution of the new species is Serbia, although we suspect a much broader distribution of this species in association with T. takachihoensis / Ulmus spp. Sequences of the COI gene identical to those from Serbian specimens are also registered in Canada and Germany.

ETYMOLOGY. — The name of the new species is derived from the most common host of T. takachihoensis , Ulmus spp.

DIAGNOSIS. — Morphologically most similar to T. complanatus ( Tomanović & Kavallieratos 2002) . Transverse carinae present on dorsal surface of propodeum ( Fig. 2E ), irregular postmedian carinae and the beginning of a closed central areola present in some specimens (in T. complanatus transverse carinae sometimes present, but discontinuous; no signs of a central pentagonal areola). Petiole with a slight constriction behind spiracular tubercles (almost parallelsided in T. complanatus ).

HOST. — Tinocallis takachihoensis .

REMARK

Since the main diagnostic character, the sculpturing of the dorsal surface of the propodeum, varies to some extent in T. ulmi Čkrkić & Tomanović , n. sp., it is advisable to take aphid hosts ( T. ulmi Čkrkić &Tomanović , n. sp. is a parasitoid of Tinocallis takachihoensis while T. complanatus mainly parasitizes aphids from the genus Therioaphis Walker, 1870 on legumes) and DNA data into account when identifying this new species.

DESCRIPTION

Female

Head ( Fig. 2A ). Eyes oval, medium sized, sparsely setose. Malar space equal to 0.14-0.15 of longitudinal eye diameter, tentorial index 0.25. Clypeus oval with 4-5 setae. Maxillary palps with 4 palpomeres, labial palps with 2 palpomeres. Antenna with 11 antennomeres, filiform, setae on flagellomeres semierect, subequal to flagellomere diameter ( Fig 2B ). Flagellomere 1 (F1) 3.6 times as long as wide, with 0-1 longitudinal placodes. F2 2.6 times as long as wide, with 1-2 longitudinal placodes ( Fig 2C ). F1 1.2 times longer than F2. F3, F4 and F5 with 1-2, 0-3 and 0-4 longitudinal placodes, respectively.

Mesosoma. Mesoscutum without notaulices, dorsal surface smooth ( Fig. 2D ). Head width/mesoscutum width ratio 1.2. Propodeum without closed central pentagonal areola ( Fig. 2E ). Antemedian carina very short; transverse carinae present, sometimes irregular. Postmedian carinae present and irregular in some paratypes.

Fore wing ( Fig. 2F ). Wing length 1 mm, width 0.4 mm. Stigma triangular, 2.6 times as long as wide and 1.7 times as long as distal abscissa of R1. Wing venation reduced, fused r and RS (r&RS) visible, reaching distally as far as R1 or shorter.

Metasoma. Petiole 1.45 times as long as wide at spiracles. Dorsal disc smooth, with 2-3 long setae on each side ( Fig. 2G ). Ovipositor sheath slightly curved downwards, length/width ratio 2.6. Prongs straight, length 0.16 mm, with 2 dorsal hairs and one claw-like apical bristle ( Fig. 2H ).

Colour. Head brown, eyes black, mouthparts yellow. Scapus, pedicel, F1 and F2 light brown, remainder of antenna brown. Mesonotum brown, propodeum and legs light brown. Wings hyaline with brown venation. Petiole light brown, rest of metasoma, including ovipositor sheaths, brown.

Body length. 1.6 mm.

Male (Paratype)

Head ( Fig. 3A ). Eyes oval, medium sized, sparsely setose. Malar space equal to 0.2 of longitudinal eye diameter, tentorial index 0.3. Clypeus oval with 2-3 setae. Maxillary palps with 4 palpomeres, labial palps with 2 palpomeres. Antenna with 13 antennomeres, filiform, setae on flagellomeres semierect, subequal to half of flagellomere diameter ( Fig. 3B ). Flagellomere 1 (F1) 2.3 times as long as wide, with 2-4 longitudinal placodes ( Fig. 3C ). F2 2.2 times as long as wide, with 1-4 longitudinal placodes. F1 subequal to F2.

Mesosoma. Mesoscutum without notaulices, dorsal surface smooth ( Fig. 3D ). Head width/mesoscutum width ratio 1.2. Propodeum in most specimens with closed central pentagonal areola ( Fig. 3E ), but some rare specimens lack the areola and have irregular transverse carinae.

Fore wing ( Fig. 3F ). Wing length 1 mm, width 0.4 mm. Stigma triangular, 2.6 times as long as wide and 2.1 times as long as distal abscissa of R1. Wing venation reduced, fused r and RS (r&RS) visible, reaching distally as far as R1 or shorter.

Metasoma. Petiole with prominent spiracles, 1.5 times as long as wide at spiracles. Dorsal disc smooth, with 2 long setae on each side ( Fig. 3G ).

Colour. Head brown, eyes black, mouthparts yellow. Scapus, pedicel, F1 and F2 light brown, remainder of antenna brown. Mesonotum and propodeum brown, legs light brown. Wings hyaline with brown venation. Petiole light brown, rest of metasoma brown ( Fig. 3H ).

Body length. 1.5 mm.

Figures

FIG. 2. — Trioxys ulmi Čkrkić & Tomanović, n. sp., female: A, head; B, antenna; C, flagellomeres 1-3; D, mesoscutum; E, propodeum; F, fore wing; G, petiole; H, ovipositor sheath and prongs. Scale bars: A, B, D, E, 100; C, G, 50; F, 200 μm.

FIG. 3. — Trioxys ulmi Čkrkić & Tomanović,n. sp., male: A, head; B, antenna; C, flagellomeres 1-3; D, mesoscutum; E, propodeum; F, fore wing; G, petiole; H, tip of metasoma and aedeagus. Scale bars: A, B, D, E, H, 100; C, G, 50; F, 200 μm.