Research Article |
Corresponding author: Hyojoong Kim ( hkim@kunsan.ac.kr ) Academic editor: Jose Fernandez-Triana
© 2022 Sangjin Kim, Željko Tomanović, Andjeljko Petrović, Jelisaveta Čkrkić, Gyeonghyoen Lee, Jongok Lim, Hyojoong Kim.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kim S, Tomanović Ž, Petrović A, Čkrkić J, Lee G, Lim J, Kim H (2022) Toxares koreanus sp. nov. – a new Toxares species from South Korea (Hymenoptera, Braconidae, Aphidiinae). Journal of Hymenoptera Research 92: 185-198. https://doi.org/10.3897/jhr.92.84146
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The genus Toxares Haliday, 1840 is a small taxon of Aphidiinae, consisting four valid species in the world. One Toxares species is recorded as new to science from South Korea, in this study. Descriptions and illustrations of the new species, T. koreanus sp. nov., are provided, together with their mitochondrial cytochrome c oxidase subunit I (COI) and D2 region of the nuclear gene for 28S rRNA (28S) sequences. The phylogenetic tree reconstructed using a combination of COI and 28S revealed the phylogenetic position of the genus Toxares within Aphidiinae.
DNA barcoding, parasitoid wasps, phylogenetics, systematics, taxonomy
The genus Toxares Haliday, 1840 is a small genus of Aphidiinae with four known species from the Holarctic. Toxares deltiger (Haliday, 1833) was the first species to be described from the genus. For a long time, it was only known in Europe, but it has been recorded from the USA (
Based on the forewing venation being related to braconid ancestors, the genus Toxares is classified within the Ephedrini tribe (
The aim of this study is to present additional knowledge about the diversity of Toxares species. After initial research of Korean aphid parasitoid fauna, we recognized a new Toxares species which is herein described and diagnostified using morphological and molecular characters. We also analysed phylogenetic relationships among genera Toxares, Ephedrus Haliday, 1833 and Praon Haliday, 1833 and discussed the phylogenetic position of the genus Toxares within Aphidiinae.
Specimens were collected by Malaise trap in a deciduous forest habitat (mostly Quercus spp.) in Mt. Beophwa which is about 450 m.a.s.l. Rosa multiflora, Cirsium japonicum, and Urtica thunbergiana were the dominant plant species. Two specimens were slide-mounted with Hoyer medium and one preserved in 70% ethanol. External structure was studied and measurements taken with a LEICA DM LS phase-contrast microscope. Morphological terminology used in this paper regarding diagnostic characters is based on that of
DNA extraction was performed using a LaboPass Tissue Kit (COSMOgenetech, Korea) following the manufacturer’s protocol. In order to conserve morphologically complete voucher specimens, the DNA extraction method was slightly modified from the ‘non-destructive method’ by
Polymerase chain reaction (PCR) amplification of COI and 28S was conducted by using AccuPower PCR PreMix (Bioneer Corp., Daejeon, Korea) in 20 μl of a reaction mixture consisting of 3 μl of DNA extract, 2 μl of primer, and 15 μl of H2O. Thermal profile for COI was as follows: denaturation for 5 min at 95 °C; 38 cycles of 20 s at 95 °C, 30 s at 45 °C, and 40 s at 72 °C; and final extension at 72 °C for 5 min. Thermal profile for 28S was as follows: denaturation for 3 min at 95 °C; 32 cycles of 30 s at 95 °C, 30 s at 48 °C, and 30 s at 72 °C; and final extension at 72 °C for 10 min. The PCR products were tested by electrophoresis on agar gel and if a band existed, we commissioned Bionocs (Korea) for sequencing and purification.
Sequences were edited with FinchTV ver. 1.4.0 (www.geospiza.com), aligned with CLUSTAL W integrated in MEGA X (
Average genetic distances were calculated using MEGA X and Kimura’s two-parameter method of base substitution (K2P,
Genetic distances (K2P) between analysed Aphidiinae species based on COI (bold) and 28S (upper right) and on both genes combined (lower left).
T. koreanus (JS1) | T. koreanus (JS1-1) | T. koreanus (JS1-2) | T. deltiger | E. helleni | E. nacheri | E. persicae | E. plagiator | P. abjectum | P. bicolor | P. dorsale | P. yomenae | V. canescens | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
T. koreanus (JS1) | 0.00 0.00 | 0.00 0.00 | 0.14 0.05 | 0.21 0.20 | 0.21 0.22 | 0.22 0.20 | 0.21 0.23 | 0.16 0.19 | 0.16 0.19 | 0.17 0.19 | 0.19 0.19 | 0.29 0.38 | |
T. koreanus (JS1-1) | 0.00 | 0.00 0.00 | 0.14 0.05 | 0.21 0.20 | 0.21 0.22 | 0.22 0.20 | 0.21 0.23 | 0.16 0.19 | 0.16 0.19 | 0.17 0.19 | 0.19 0.19 | 0.29 0.38 | |
T. koreanus (JS1-2) | 0.00 | 0.00 | 0.14 0.05 | 0.21 0.20 | 0.21 0.22 | 0.22 0.20 | 0.21 0.23 | 0.16 0.19 | 0.16 0.19 | 0.17 0.19 | 0.19 0.19 | 0.29 0.38 | |
T. deltiger | 0.09 | 0.10 | 0.10 | 0.23 0.18 | 0.22 0.21 | 0.20 0.18 | 0.23 0.21 | 0.18 0.19 | 0.19 0.18 | 0.18 0.18 | 0.20 0.18 | 0.31 0.38 | |
E. helleni | 0.21 | 0.21 | 0.21 | 0.21 | 0.10 0.06 | 0.20 0.05 | 0.09 0.06 | 0.22 0.22 | 0.21 0.22 | 0.22 0.22 | 0.23 0.23 | 0.29 0.39 | |
E. nacheri | 0.21 | 0.21 | 0.21 | 0.21 | 0.08 | 0.22 0.08 | 0.03 0.00 | 0.23 0.21 | 0.21 0.22 | 0.21 0.22 | 0.21 0.21 | 0.27 0.41 | |
E. persicae | 0.21 | 0.21 | 0.21 | 0.20 | 0.13 | 0.16 | 0.22 0.08 | 0.22 0.20 | 0.21 0.20 | 0.22 0.20 | 0.22 0.21 | 0.32 0.36 | |
E. plagiator | 0.21 | 0.21 | 0.21 | 0.22 | 0.08 | 0.02 | 0.16 | 0.24 0.22 | 0.21 0.22 | 0.22 0.22 | 0.21 0.22 | 0.27 0.42 | |
P. abjectum | 0.17 | 0.17 | 0.17 | 0.17 | 0.22 | 0.23 | 0.21 | 0.23 | 0.07 0.00 | 0.07 0.00 | 0.10 0.02 | 0.32 0.42 | |
P. bicolor | 0.17 | 0.17 | 0.17 | 0.18 | 0.22 | 0.22 | 0.21 | 0.22 | 0.04 | 0.03 0.00 | 0.08 0.02 | 0.29 0.42 | |
P. dorsale | 0.17 | 0.17 | 0.17 | 0.18 | 0.22 | 0.22 | 0.21 | 0.22 | 0.04 | 0.02 | 0.08 0.02 | 0.28 0.42 | |
P. yomenae | 0.18 | 0.18 | 0.18 | 0.19 | 0.22 | 0.22 | 0.22 | 0.22 | 0.06 | 0.05 | 0.05 | 0.28 0.44 | |
V. canescens | 0.32 | 0.32 | 0.32 | 0.33 | 0.32 | 0.32 | 0.33 | 0.32 | 0.361 | 0.34 | 0.34 | 0.34 |
MEGA X was used to construct phylogenetic trees based on each gene used in the study, as well as a combined tree employing concatenated sequences of both genes.
Phylogenetic relationships were reconstructed using Maximum Likelihood (ML) and Maximum Parsimony (MP) methods.
Toxares koreanus sp. nov. morphologically resembles T. shigai in having elongated flagellomere 1 (F1), which is clearly longer than flagellomere 2 (F2) and elongated petiole at the spiracles level. However, T. koreanus sp. nov. is easily distinguished from T. shigai in the shape of petiole (petiole with parallel sides in T. koreanus sp. nov., while laterally expanded and longitudinally striated in T. shigai), yellow colored F1–F3 and even a yellowish base of F4 in T. koreanus sp. nov., while light brown colored F1–F3 in T. shigai. Also, T. koreanus sp. nov. morphologically resembles T. macrosiphophagum, but differs in more elongated F1 which is clearly longer than F2, more elongated petiole, and color of basal flagellomeres (yellow colored F1–F3 and yellow base of F4 in T. koreanus sp. nov., and yellowish F1 and F2 in T. macrosiphophagum).
Female (Fig.
Mesosoma. Mesoscutum smooth, rounded, with mid pit in the middle posterior part. Notaulices distinct in very short ascendent portion of anterolateral margin, with two rows of long setae along the dorsolateral part of mesoscutum (Fig.
Metasoma. Petiole (Fig.
Body length : about 1.70–2.20 mm.
Coloration. General body color light brown to yellow. Scape, pedicel and F1–F3 yellow, F4 basally light brown, remaining antennal parts brown. Mouthparts yellow. Head brown. Mesoscutum light brown to brown. Propodeum light brown. Legs yellow with brown apices. Petiole yellow to light brown, other metasomal terga light brown. Ovipositor sheath yellow.
Male (Fig.
The name of the new species is derived from Republic of Korea where it was found.
Holotype : Korea • 1 ♀; Mt. Beophwa, San 128-1, Wolgok-ri, Cheoncheon-myeon, Jasnsu-gun, Jeollabuk-do; 35°42'07.6"N, 127°31'54.7"E; collected by Malaise trap: 06.V–24.V.2021; leg. Yeonghyeok Yu, Sangjin Kim, JuHyeong Sohn, Yunjong Han, Gyeongyeon Lee. Holotype deposited in National Institute of Biological Resources, Incheon, Republic of Korea slide mounted.
Paratypes : Korea • 1 ♂; Mt. Beophwa, San 128-1, Wolgok-ri, Cheoncheon-myeon, Jasnsu-gun, Jeollabuk-do; 35°42'07.6"N, 127°31'54.7"E; collected by Malaise trap: 06.V–24.V.2021; leg. Yeonghyeok Yu, Sangjin Kim, JuHyeong Sohn, Yunjong Han, Gyeongyeon Lee. Paratype slide mounted and deposited in National Institute of Biological Resources, Incheon, Republic of Korea.
Korea • 2 ♀; 1 ♀, Mt. Beophwa, San 128-1, Wolgok-ri, Cheoncheon-myeon, Jasnsu-gun, Jeollabuk-do; 35°42'07.6"N, 127°31'54.7"E; collected by Malaise trap: 06.V–24.V.2021; leg. Yeonghyeok Yu, Sangjin Kim, JuHyeong Sohn, Yunjong Han, Gyeongyeon Lee • 1 ♀, same locality; collected by Malaise trap: 24.V–02.VI.2021; leg. Yeonghyeok Yu, Sangjin Kim, JuHyeong Sohn, Yunjong Han, Gyeongyeon Lee. Specimens deposited dry and immersion-mounted in Kunsan National University, Jeollabuk-do, Republic of Korea.
Obtained phylogenetic trees reconstructed based on COI, 28S and the combination of both genes showed identical topology, and the tree based on the combination of both genes is shown on Fig.
Calculated genetic distances (Tables
The genus Toxares is considered as one of the most basal within the subfamily Aphidiinae, classified within the tribe Ephedrini (
Toxares koreanus sp. nov. is the fifth known member of the genus Toxares and fourth species described from Asia. Based on the currently available data about the distribution of described species, we can assume that the origin of this genus should be Far Eastern Asia. Considering the habitat and plant diversity in Far Eastern Asia, we can expect to discover additional species of the genus Toxares.
Molecular analysis using COI and 28S supports the description of the new species. Toxares koreanus sp. nov. is clearly separated from T. deltiger by both genes (Fig.
Molecular markers employed in this study show some incongruence with morphological characters. While Toxares is morphologically most similar to Ephedrus, molecular data suggests the genus is closer to Praon (Fig.
Although the genus Toxares, as a member of Ephedrini tribe, is already considered as basal within Aphidiinae (
Within group mean distances | |||
---|---|---|---|
COI | 28S | combined | |
Toxares | 0.07 | 0.02 | 0.05 |
Ephedrus | 0.14 | 0.06 | 0.10 |
Praon | 0.07 | 0.01 | 0.04 |
Between group mean distances (COI/ 28S/ combined) | |||
Toxares | Ephedrus | Praon | |
Toxares | |||
Ephedrus | 0.21/ 0.21/ 0.21 | ||
Praon | 0.19/ 0.18/ 0.17 | 0.22/ 0.22/ 0.22 |
This work was supported by a grant from the National Institute of Biological Resources (NIBR), funded by the Ministry of Environment (MOE) of the Republic of Korea (NIBR202102204). This research was also supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (2018R1D1A3B07044298). The contribution of ŽT, AP and JČ is supported by the Serbian Ministry of Science and Education (451-03-68/2022-14/200178).
Figure S1
Data type: Image (tif file)
Explanation note: Figure S1. Habitus of Toxares koreanus sp. nov., female.