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Research Article
Phylogeny of the Chinese species groups of the subgenus Homoneura Wulp, 1891 (Diptera, Lauxaniidae, Homoneurinae) based on morphological characters
expand article infoYao Yao‡, Chaoyang Kong‡, Pu Miao§, Shengjuan Zhao‡, Wenliang Li‡
‡ Henan University of Science and Technology, Luoyang, China
§ Henan Tobacco Company Luoyang company, Luoyang, China

Corresponding author: Wenliang Li ( wenliangli@haust.edu.cn )

Academic editor: Alexssandro Camargo
© 2024 Yao Yao, Chaoyang Kong, Pu Miao, Shengjuan Zhao, Wenliang Li.
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: Yao Y, Kong C, Miao P, Zhao S, Li W (2024) Phylogeny of the Chinese species groups of the subgenus Homoneura Wulp, 1891 (Diptera, Lauxaniidae, Homoneurinae) based on morphological characters. Deutsche Entomologische Zeitschrift 71(2): 241-254. https://doi.org/10.3897/dez.71.120389
ZooBank: urn:lsid:zoobank.org:pub:243FCE92-70C3-431B-93F8-BF82B2A9823E
Open Access

Abstract

The subgenus Homoneura Wulp, 1891 (Diptera, Lauxaniidae, Homoneurinae) is highly diverse with more than 220 species known from China, representing more than 80% of the Chinese genus Homoneura Wulp, 1891. These species were assigned into 21 species groups in studies mainly focusing on the classification and description of species. The phylogenetic relationships of each subgenus of Homoneura and the phylogenetic relationship of the species groups are still not well understood. We investigated the male morphology to provide the basis to further revise the species groups of this subgenus. In this survey, 230 species were examined and 117 morphological characters obtained, a phylogenetic analysis was conducted using the maximum parsimony analysis with TNT and WinClada. The analyses yielded 45 most parsimonious trees and one strict consensus tree. A phylogenetic hypothesis is proposed dividing the subgenus Homoneura into 12 species groups: H. (H.) nigrifacies, H. (H.) pallida, H. (H.) patella, H. (H.) beckeri, H. (H.) formosae, H. (H.) henanensis, H. (H.) nigra, H. (H.) notostigma, H. (H.) ornatifrons, and H. (H.) trispina, H. (H.) laticosta, and H. (H.) quinquenotata. This research provides valuable contributions towards a better understanding of the phylogenetic relationships within the subgenus Homoneura. However, the monophyly of the genus and subgenus was not supported.

Key Words

Maximum parsimony, monophyly, morphology, phylogenetic relationship, revision

Introduction

The genus Homoneura Wulp, 1891 (Diptera, Lauxaniidae, Homoneurinae) comprises more than 750 described species in eight known subgenera distributed worldwide (Chen 2022). Homoneura is widely distributed in all major zoogeographical regions except for the Neotropical region and plays a very important role in the ecological system (Shi et al. 2017). The subgenus Homoneura Wulp, 1891 comprises more than 700 described species and has the highest species richness of Lauxaniidae (You et al. 2023). When the classification of this group entered the second stage of prosperity and development, the number of described species increased markedly, significantly reducing the efficiency of comparative morphological studies. Therefore, some scholars began to study species groups among the subgenera of Homoneura based on characters such as wing spots and male genitalia. Miller (1977a, 1977b) made a comprehensive revision of 50 species, nine groups and four subgenera of Homoneura distributed in the Nearctic region in his monograph “Taxonomy and Biology of Homoneura in the Nearctic region”. In particular, the establishment of species groups was an important contribution to the systematic study of Homoneura (Miller 1977a, 1977b). Later, Papp proposed two species groups from the Palaearctic region and four species groups from the Oriental region (Papp 1978; Papp et al. 2006). Sasakawa (1992) proposed a new species group from the Oriental region. Kim (1994) distributed the Australian species of Homoneura into 15 species groups, and established 20 species groups of the global subgenera of Homoneura. Shi and Yang (2014) divided the Chinese species of the Homoneura subgenus into 21 species groups, but some of the species could not be classified into species groups. Up to now, only five scholars have made a morphological classification of species groups, because of the loss or destruction of type specimens. The descriptions were too simple to study carefully. The accuracy and availability of a species group system is doubtful, and the phylogenetic relationships of existing species groups have not been comprehensively tested.

The phylogenetical approach is an important way to reveal the relationships between taxa; however, relationships within Homoneura are relatively behind. Stuckenberg (1971) hypothesized the relationships among 19 genera of Homoneurinae based on morphological characters, and divided the 19 genera into three generic groups, with Homoneura in the first group; Sasakawa (1992) hypothesized the phylogenetic relationships among five subgenera of Homoneura based on six morphological characters, with the subgenera distributed into two clades, one containing the subgenera Chaetohomoneura Malloch, 1927 and Neohomoneura Malloch, 1927, and the other comprising three subgenera with Euhomoneura Malloch, 1927 and Homoneura presented as sister groups, and the subgenus Minettioides Malloch, 1929 closely related to these (Sasakawa 1992). In the only existing molecular phylogenetic study on the generic relationships of Homoneura, Shi et al. (2017) explored the relationships based on two mitochondrial and two nuclear genetic markers, and the hypothesis of subgeneric monophyly was not corroborated. Kong et al. (2022) presented the first morphological phylogeny of Homoneura, and the hypothetical monophyly of the genus and subgenus was also not supported. Furthermore, the phylogenetic relationships among other subgenera of Homoneura were also discussed. The evolutionary relationships among the Homoneura subgenera are not completely clear, and phylogenetic relationships of some species groups have not been studied yet, making systematic classification studies in this genus difficult. At present, no phylogenetic studies of the Homoneura subgenera have been published using morphological evidence. Despite its high diversity and ecological significance, the phylogenetic relationships in Homoneura and its subgenera remain to be studied.

Methods

All the specimens are deposited in College of Horticulture and Plant Protection, Henan University of Science and Technology, Henan, China (Suppl. material 1).

Morphological study and terminology

General terminology follows Cumming and Wood (2017), and Gaimari and Miller (2021). The specimens were observed with a Motic SMZ-168 stereomicroscope and the external morphological characters were examined. Genitalia preparations were made by removing and macerating the apical portion of the abdomen in cold saturated NaOH for six hours, then rinsing and neutralizing them with glacial acetic acid for dissection and study. After examination in glycerine, they were transferred to fresh glycerine and stored in a microvial pinned below the specimen or moved to an ethanol tube together with the wet specimens. Most characters were illustrated using photographs and line drawings. Photographs were taken using a Canon EOS6D microscope (Canon, Tokyo, Japan) and stacked using Helicon Focus v7.0.2.0 (Helicon Soft, Kharkiv, Ukraine). Line drawings were drawn with Adobe Illustrator 2021 v25.2.1 (Adobe, San Jose, USA).

Specimen morphological characters

The morphological characters were numerically coded (Suppl. material 2). Ninety-eight characters are binary and 25 are multistate. Plesiomorphic states were coded with (0), and apomorphic with (1,2,3), missing character states were coded with (?), and inapplicable states were scored as (–).

List of characters used in the cladistic analysis

The partial characters and all pictures were adapted from Kong et al. (2022) and revised accordingly for the purposes of deeper research.

Head:

  1. Size of head, height of head/width of head in frontal view and the eyes are included: (0) ≤ 4/5 (Fig. 1A); (1) > 4/5 (Fig. 1J).
  2. Color of ocellar triangle: (0) black (Fig. 1A); (1) brown to yellow (Fig. 1E).
  3. Number of ocellar seta: (0) 2; (1) 3.
  4. Length of ocellar seta/length of anterior fronto-orbital seta: (0) ≥ 1 (Fig. 1F); (1) < 1 and ≥ 1/2;(2) < 1/2 (Fig. 1E).
  5. Length of anterior fronto-orbital seta/length of posterior fronto-orbital seta: (0) < 1 (Fig. 1B); (1) ≥ 1 (Fig. 1M).
  6. Length between anterior fronto-orbital seta and posterior fronto-orbital seta/length between posterior fronto-orbital seta and inner vertical bristles: (0) > 1/2 (Fig. 1G); (1) ≤ 1/2.
  7. Frons: (0) flat (Fig. 1F); (1) distinct uplifted; (2) distinct concave (Fig. 1J).
  8. Length of frons/width of frons: (0) ≤ 1 (Fig. 1A); (1) > 1 (Fig. 1E).
  9. Middle of frons: (0) without spot or stripe (Fig. 1L); (1) with a dark median longitudinal stripe extending from anterior margin to the ocellar triangle or the top of the head (Fig. 1C).
  10. Between the middle of frons and fronto-orbital seta: (0) with two longitudinal stripes extending to both sides of the ocellar triangle (Fig. 1A); (1) without stripe (Fig. 1B).
  11. The area around the fronto-orbital setae and the outer vertical bristles: (0) without spot or stripe (Fig. 1H); (1) with spot (Fig. 1A); (2) with stripe along the bases (Fig. 1D).
  12. Presence of a spot at the costal margin of frons: (0) absent (Fig. 1I); (1) present.
  13. Facial angle of frons: (0) approach straight angle; (1) approach right angle.
  14. Color of face: (0) black (Fig. 1L); (1) brown to yellow (Fig. 1D).
  15. Spot on face: (0) absent (Fig. 1I); (1) irregular; (2) round (Fig. 1M).
  16. Middle of face: (0) flat (Fig. 1I); (1) distinct uplifted (Fig. 1K).
  17. Ventral margin of face: (0) strumaes on both sides (Fig. L); (1) lamellar processes in the middle (Fig. 1J); (2) flat (Fig. 1D).
  18. Width of ventral margin of face/height of gena: (0) ≥ 3 (Fig. 1I); (1) < 3 (Fig. 1J).
  19. Spot on gena: (0) absent (Fig. 1N); (1) present (Fig. 1O).
  20. Below eye on gena: (0) without strong seta (Fig. 1M); (1) with strong seta (Fig. 1H).
  21. Length of gena/length of eye: (0) <1/3 (Fig. 1N); (1) ≥ 1/3 (Fig. 1J).
  22. Face and gena: (0) do not extend (Fig. 1L); (1) distinct extend ventrally (Fig. 1J).
  23. Color of pedicel: (0) black (Fig. 1H); (1) brown to yellow (Fig. 1G).
  24. Number of scape long bristle that is not shorter than the length of the first flagellomere: (0) 0 (Fig. 1G); (1) 2 (Fig. 1J).
  25. Color of flagellomere: (0) monochrome (Fig. 1P); (1) bicolor (Fig. 1N).
  26. Arista: (0) plumose (arista with longest setulae, not less than the width of the first flagellomere) (Fig. 1M); (1) pubescent (arista with longest setulae shorter than the width of the first flagellomere) (Fig. 1H).
  27. Length of the first flagellomere/width of the first flagellomere: (0) ≥ 2 (Fig. 1M); (1) < 2.
  28. Spot between base of antennae and inner margin of eye: (0) present (Fig. 1H); (1) absent (Fig. 1E).
  29. Color of proboscis: (0) black; (1) brown to yellow (Fig. 1N).
  30. Color of palpus: (0) monochrome, black (Fig. 1P); (1) monochrome, brown or yellow (Fig. 1O); (2) bicolor.
  31. Occiput: (0) without stripe (Fig. 1G); (1) with distinct narrow stripe (as wide as ocellar triangle); (2) with distinct wide stripe (distinctly longer than ocellar triangle) (Fig. 1C).

Thorax:

  1. Mesonotum: (0) with distinct longitudinal stripe (Fig. 2C); (1) without longitudinal stripe (Fig. 2E).
  2. Base of dorsocentral seta and prescutellar acrostichal seta: (0) without spot (Fig. 2E); (1) with spot (Fig. 2B).
  3. Pre-sutural dorsocentral seta: (0) absent (Fig. 2E); (1) present (Fig. 2D).
  4. Post-sutural dorsocentral seta: (0) 3 (Fig. 2A); (1) 2 (Fig. 2D).
  5. Rows of acrostichal seta: (0) seven or more rows (Fig. 2E); (1) six or less rows (Fig. 2D).
  6. Acrostichal seta: (0) weak, short hair (Fig. 2B); (1) strong seta (Fig. 2D).
  7. Mesonotum prescutellar acrostichal seta: (0) longer than acrostichal seta with hair; (1) hair, as long as acrostichal seta with hair.
  8. Mesonotum scutellar suture: (0) without spot (Fig. 2D); (1) with spot.
  9. Mesonotum pruinose stripe: (0) no pruinose stripe; (1) a broad pruinose stripe from face, antenna, frons, mesonotum to the end of scutellum.
  10. Supra-alar seta: (0) one (Fig. 2F); (1) two, the latter is about half as long as the former; (2) two, the latter is about the same length as the former one.
  11. Intra-alar seta: (0) one, strong (as long as supra-alar seta); (1) one, weak (half the length of supra-alar seta); (2) 0.
  12. Katepisternal seta: (0) two (Fig. 2F); (1) one (Fig. 2C).

Leg:

  1. Length of leg/length of body: (0) ≤ 1; (1) > 1.
  2. Posterior ventral seta on fore femur: (0) five or more (Fig. 2L); (1) four or less (Fig. 2G).
  3. Ctenidium short seta on fore femur: (0) absent; (1) ten or less; (2) eleven or more (Fig. 2G).
  4. Anterior seta on mid femur: (0) six or more; (1) five or less (Fig. 2I).
  5. Posterior seta on mid tibia: (0) absent (Fig. 2J); (1) present (Fig. 2K).
  6. Apical ventral seta on mid tibia: (0) one; (1) two (Fig. 2J); (2) three (Fig. 2K); (3) four.
  7. Preapical anterior dorsal seta on hind femur: (0) present (Fig. 2H); (1) absent.
  8. Anteroventral seta on hind femur: (0) present; (1) absent.

Wing:

  1. Length of wing/width of wing: (0) < 2.7 (Fig. 3A); (1) ≥ 2.7 (Fig. 3D).
  2. Wing: (0) most hyaline or pale yellow (five or less spots and wing spots occupy a small area of the wing) (Fig. 3E); (1) most brown or black (six or more spots and wing spots occupy a large area of the wing) (Fig. 3A).
  3. Anterior margin of the wing (in front of R2+3): (0) most hyaline or pale yellow (spots on the wings less than half of the anterior margin of the wings) (Fig. 3F); (1) mostly brown or black (spots on the wings not less than half of the wings, while still a little part with no spots) (Fig. 3B); (2) all brown, fading from costa vein to the middle; (3) all brown, no change in color from costa vein to the middle.
  4. Short black setae on costal margin of wing: (0) extend to between R 2+3 and R 4+5 (Fig. 3G); (1) extend to R 4+5 (Fig. 3C).
  5. Spot on r 1 cell: (0) absent (Fig. 3E); (1) present (Fig. 3C).
  6. Spot on R 2+3: (0) absent (Fig. 3G); (1) 1, a hyaline space (Fig. 3H); (2) 2 (Fig. 3C); (3) ≥ 3; (4) all brown (Fig. 3A).
  7. Tip of R 4+5: (0) without spot (Fig. 3E); (1) with one spot (irregular) (Fig. 3H); (2) with two spots (irregular), far away from crossvein r-m (Fig. 3D); (3) with two spots (irregular), next to crossvein r-m (Fig. 3A); (4) with three spots (irregular) (Fig. 3C); (5) many small spots, reticular connection (Fig. 3A); (6) many sexangular spots (a small spot in the middle).
  8. Crossvein r-m: (0) without spot (Fig. 3G); (1) only strengthened or with a inconspicuous stripe around (Fig. 3E); (2) distinct spots (Fig. 3H); (3) circular spots (Fig. 3B).
  9. Crossvein dm-cu: (0) without spot (Fig. 3G); (1) only overstrike crossvein or an inconspicuous stripe around (Fig. 3E); (2) distinct spots (Fig. 3F); (3) circular spots (Fig. 3D).
  10. Tip of M 1: (0) without spot (Fig. 3G); (1) one spot (Fig. 3F); (2) two spots (Fig. 3H); (3) many small spots, reticular connection (Fig. 3A).
  11. Stripe on penultimate section of CuA1: (0) absent (Fig. 3F); (1) present (Fig. 3D).
  12. Spot on base of radial vein and medial vein: (0) absent (Fig. 3E); (1) present (Fig. 3B).
  13. Anal vein: (0) normal (Fig. 3H); (1) lack (Fig. 3B).
  14. Anterior cubital cell: (0) without spot (Fig. 3C); (1) with spot (Fig. 3A).
  15. 2nd (between R 1 and R 2+3) section/3 rd (between R 2+3 and R 4+5) section: (0) ≥ 3; (1) < 3.
  16. 3 rd (between R 2+3 and R 4+5) section/4 th (between R 4+5 and M 1) section: (0) ≥ 1.5; (1) < 1.5.
  17. The end of R 2+3: (0) not bend to costal margin (Fig. 3F); (1) bend to costal margin (Fig. 3C).
  18. Length of the ultimate section of M1/ length of the penultimate section of M1: (0)> 1; (1) ≤ 1.
  19. Length of the ultimate section of CuA1/length of the penultimate section of CuA1: (0) < 1/5; (1) ≥ 1/5.
  20. Crossvein r-m: (0) before or in the middle of the discal cell (Fig. 3F); (1) behind the middle of the discal cell (Fig. 3D).
  21. Color of knob part of haltere: (0) black; (1) brown or yellow.

Abdomen:

  1. Spot on middle of tergite 2: (0) absent (Fig. 4B); (1) present (Fig. 4A).
  2. Spot on side of tergite 2: (0) absent (Fig. 4F); (1) present (Fig. 4D).
  3. Spot on middle of tergite 3: (0) absent (Fig. 4C); (1) present (Fig. 4A).
  4. Spot on side of tergite 3: (0) absent (Fig. 4E); (1) present (Fig. 4D).
  5. Spot on middle of tergite 4: (0) absent (Fig. 4C); (1) present (Fig. 4A).
  6. Spot on side of tergite 4: (0) absent (Fig. 4F); (1) present (Fig. 4D).
  7. Spot on middle of tergite 5: (0) absent (Fig. 4C); (1) present (Fig. 4B).
  8. Spot on side of tergite 5: (0) absent (Fig. 4F); (1) with striped spot (Fig. 4D); (2) with circular spot (Fig. 4E).
  9. Spot on middle of tergite 6: (0) absent; (1) present.
  10. Spot on side of tergite 6: (0) absent; (1) present.
  11. Posterior margin of tergite: (0) not change color (Fig. 4E); (1) distinct dark brown stripe (2) distinct light brown stripe (Fig. 4B).
  12. Sternite 5: (0) not differentiated; (1) differentiated into a digitiform process.
  13. Short spine at posterior margin of sternite 5: (0) absent; (1) present.

Male genitalia:

  1. Syntergosternite and epandrium: (0) not fused; (1) fused.
  2. Shape of syntergosternite: (0) semicircular (Fig. 5C); (1) circular, without ventral processes (Fig. 5A); (2) circular, with ventral processes (Fig. 5B).
  3. Length of dorsal margin of syntergosternite/length of posterior margin of syntergosternite: (0) < 2/3; (1) ≥ 2/3.
  4. Dorsal margin of syntergosternite: (0) without short hair (Fig. 5C); (1) with short hair (Fig. 5B).
  5. Syntergosternite around the spiracle: (0) without short hair (Fig. 5C); (1) with short hair (Fig. 5A).
  6. Costal margin of epandrium: (0) with sharp process or concave; (1) without sharp process or without concave.
  7. Length of dorsal margin of epandrium/length of ventral margin of epandrium: (0) > 1/2; (1) ≤ 1/2.
  8. Surstylus: (0) separated from epandrium (Fig. 6A); (1) not separated from epandrium (Fig. 6D).
  9. Length of the longest surstylus/height of epandrium: (0) ≥ 1/2 (Fig. 6D); (1) < 1/2 (Fig. 6B).
  10. Shape of the apex of surstylus: (0) sharp (Fig. 6A); (1) blunt (Fig. 6C).
  11. Shape of surstylus: (0) bent (Fig. 6A); (1) straight (Fig. 6C).
  12. Width of the middle of surstylus/length of surstylus: (0) < 1/2 (Fig. 6B); (1) ≥ 1/2 (Fig. 6A).
  13. Fine teeth or terminal processes on surstylus: (0) absent (Fig. 6D); (1) present (Fig. 6C).
  14. Hypandrium: (0) present; (1) absent.
  15. Middle of hypandrium: (0) connected; (1) unconnected.
  16. Shape of hypandrium: (0) U-shaped (Fig. 7A); (1) Y-shaped (Fig. 5D); (2) H-shaped (Fig. 7D); (3) W-shaped (Fig. 7B).
  17. Middle of anterior margin of hypandrium: (0) without inner processes (Fig. 7D); (1) with inner processes (Fig. 5D).
  18. Both sides at anterior margin of hypandrium: (0) without inner processes; (1) with inner processes.
  19. Middle of posterior margin of hypandrium: (0) without ventral process (Fig. 7A); (1) with ventral process (Fig. 7B).
  20. Both sides at posterior margin of hypandrium: (0) without ventral process; (1) with ventral process.
  21. Gonite: (0) present (Fig. 7D); (1) absent (Fig. 7C).
  22. Seta on gonite: (0) present (Fig. 7D); (1) absent (Fig. 7A).
  23. Length of gonite/length of phallus: (0) ≥ 1/2 (Fig. 7D); (1) < 1/2 (Fig. 7A).
  24. Tip of gonite: (0) sharp (Fig. 7D); (1) blunt (Fig. 7A).
  25. Phallus: (0) without thorn or sharp process (Fig. 7C); (1) with thorn or sharp process (Fig. 7B).
  26. Lateral view of the tip of phallus: (0) bent (Fig. 7C); (1) straight (Fig. 7A).
  27. Tip of phallus: (0) not inflated; (1) blunt round apically.
  28. Apex of phallus: (0) sharp (Fig. 7C); (1) not sharp (Fig. 7B).
  29. Phallus: (0) with distinct apical concavity; (1) without distinct apical concavity (Fig. 7B).
  30. Aedeagal apodeme: (0) present; (1) absent.
  31. Length of aedeagal apodeme/length of phallus: (0) < 1 (Fig. 7D); (1) ≥ 1 (Fig. 7A).
  32. Base of aedeagal apodeme: (0) separate and extend (Fig. 7D); (2) not separate (Fig. 7C).
Figure 1. 

Head characters. Homoneura (Homoneura) picta (de Meijere, 1904) (A, N); Homoneura (Homoneura) flavida Shi & Yang, 2009 (B, C, D, O); Homoneura (Minettioides) orientis (Hendel, 1908) (E); Homoneura (Euhomoneura) yanqingensis Shi, Gao & Li, 2017 (F, I); Homoneura (Neohomoneura) tricuspidata Shi & Yang, 2008 (G); Prosopophorella yoshiyasui Sasakawa, 2001 (H, J, K); Minettia (Frendelia) longipennis (Fabricius, 1794) (L, P); Pachycerina decemlineata de Meijere, 1914 (M).

Figure 2. 

Thoracic and leg characters. Homoneura (Homoneura) flavida Shi & Yang, 2009 (A, G, H); Homoneura (Homoneura) picta (de Meijere, 1904) (B); Pachycerina decemlineata de Meijere, 1914 (C); Homoneura (Euhomoneura) yanqingensis Shi, Gao & Li, 2017 (D, I, J); Homoneura (Neohomoneura) tricuspidata Shi & Yang, 2008 (E, K); Homoneura (Minettioides) orientis (Hendel, 1908) (F); Minettia (Frendelia) longipennis (Fabricius, 1794) (L).

Figure 3. 

Wing characters. A. Homoneura (Homoneura) picta (de Meijere, 1904); B. Noonamyia umbrellata Shi & Yang, 2009; C. Homoneura (Homoneura) posterotricuspis Gao, Shi & Han, 2016; D. Prosopophorella yoshiyasui Sasakawa, 2001; E. Homoneura (Homoneura) flavida Shi & Yang, 2009; F. Homoneura (Neohomoneura) zengae Shi & Yang, 2008; G. Minettia (Frendelia) longipennis (Fabricius, 1794); H. Homoneura (Euhomoneura) yanqingensis Shi, Gao & Li, 2017.

Figure 4. 

Abdomen characters. Homoneura (Homoneura) picta (de Meijere, 1904) (A, D); Homoneura (Neohomoneura) tricuspidata Shi & Yang, 2008 (B); Homoneura (Euhomoneura) yanqingensis Shi, Gao & Li, 2017 (C, F); Homoneura (Minettioides) orientis (Hendel, 1908) (E).

Figure 5. 

Syntergosternite and hypandrium characters. A. Homoneura (Homoneura) dorsacerba Gao, Shi & Han, 2016; B. Homoneura (Homoneura) posterotricuspis Gao, Shi & Han, 2016; C. Homoneura (Homoneura) procerula Gao & Yang, 2005; D. Cestrotus liui Shi, Yang & Gaimari, 2009.

Figure 6. 

Epandrium characters. A. Homoneura (Homoneura) trispina; B. Homoneura (Homoneura) dorsacerba; C. Homoneura (Homoneura) posterotricuspis; D. Pachycerina decemlineata.

Figure 7. 

Aedeagal complex characters. A. Noonamyia umbrellata; B. Homoneura (Homoneura) beckeri; C. Pachycerina decemlineata; D. Homoneura (Homoneura) procerula.

Phylogenetic analysis

In this research, two species of Lauxaniinae: Minettia (Frendelia) longipennis (Fabricius, 1794) and Pachycerina decemlineata Meijere, 1914 and representative species of all genera of Homoneurinae found in China except Homoneura, Cestrotus liui Li et al., 2009, Dioides incurvatus Shi et al., 2009, Noonamyia umbrellata Shi et al., 2009, Phobeticomyia motuoensis Li et al., 2020. and Prosopophorella yoshiyasui Sasakawa, 2001 were used as an outgroup. Minettia (Frendelia) longipennis is the first outgroup.

The phylogenetic construction was conducted using maximum-parsimony analysis. The unambiguous characters were mapped on the tree using WinClada version v1.00.08 (Nixon 2002). The maximum-parsimony tree is shown in Suppl. material 3, Bootstrap values (BS) and Bremer support (B) values are presented next to the nodes. The analysis was performed in TNT (version 1.1; Goloboff et al. 2008) using implied weighting. For the implied weighting analyses, K values of 2–5, 10, 15, 20, 25 and 30 were used, maintaining the maximum number of trees (10000 trees). All analyses were performed using traditional searches, 900 replicates holding up to 45 trees per replication. Branch support values were verified through bootstrap analyses on NONA 2.0 (Goloboff 1999). The Bremer support value or decay index was calculated using TNT.

Results

Phylogenetic analysis of Homoneura

On the basis of our research, 117 morphological characters were obtained from different body parts of the adults; from the head (31 characters, Fig. 1), thorax (12 characters, Fig. 2A–F), legs (8 characters, Fig. 2G–L), wings (21 characters, Fig. 3), abdomen (13 characters, Fig. 4), and genitalia (32 characters, Fig. 5–7). Branch length is the shortest and the topology structure no longer changes when K is not less than 20. Forty-five maximum-parsimonious trees were produced when K = 30. Different maximum-parsimonious trees mainly affect the monophyletic and interspecific relationships of Homoneura (Homoneura) henanensis group, and the topology structure of each branch end. The resultant strict consensus tree was calculated using TNT (Fig. 8) [branch length = 1413, consistency index (CI) = 0.11, retention index (RI) = 0.73].

Figure 8. 

Phylogenetic relationships of H. moneura. I. H. (H.) ornatifrons group; II. H. (H.) patella group; III. H. (H.) notostigma group; IV. H. (H.) nigra group; V. H. (H.) nigrifacies group; VI. H. (H.) trispina group; VII. H. (H.) beckeri group; VIII. H. (H.) formosae group; IX. H. (H.) laticosta group; X. H. (H.) pallida group; XI. H. (H.) henanensis group; XII. H. (H.) quinquenotata group. Left, bootstrap values ≥ 50%; right, Bremer support values.

Relationships among the Homoneura subgenera occurring in China

The monophyly of the subgenus Homoneura, Neohomoneura, Euhomoneura and Chaetohomoneura is not supported. The monophyly of the subgenus Minettioides could not be verified due to the limited taxa. One species of the subgenus Chaetohomoneura appears at an end node within the subgenus Neohomoneura, while the subgenus Euhomoneura, Neohomoneura, Minettioides and Chaetohomoneura also appear mosaically distributed within the subgenus Homoneura.

Key to the species groups of the Homoneura subgenus based on the maximum-parsimony tree

1 Wing without spots or only with pale spots on crossveins (Fig. 3E, G) 2
– Wing with many distinct brown spots (Fig. 3A) 10
2 Body yellow or brown (Fig. 2C, D, E, F) 3
– Body black (Fig. 2A, B) 6
3 Two stripes along orbital bristles (Fig. 1A), a triangular brown stripe in the middle of frons (Fig. 1C); hypandrium W-shaped H. (H.) beckeri group
– Frons without stripe (Fig. 1B, L); hypandrium not W-shaped 4
4 Post pedicel bicolor (Fig. 1N); mesonotum scutoscutellar suture with black spots (Fig. 1H) H. (H.) notostigma group
– Flagellomere yellow (Fig. 1P); mesonotum scutellar suture without spot (Fig. 2D) 5
5 Length of ocellar seta is shorter than the length of anterior fronto-orbital seta (Fig. 1E) H. (H.) patella group
– Length of ocellar seta is longer than the length of anterior fronto-orbital seta (Fig. 1F) H. (H.) laticosta group
6 Prescutellar acrostichal seta weak, same as acrostichal seta H. (H.) ornatifrons group
– Prescutellar acrostichal seta strong, longer than acrostichal seta 7
7 With a broad white pruinose stripe from face to the end of scutellum (Fig. 4B) H. (H.) nigra group
– Without pruinose stripe from face to scutellum (Fig. 4E) 8
8 Tergite 5 with a pair of black spots (Fig. 4B) H. (H.) formosae group
– Tergite 5 without spots (Fig. 4C) 9
9 Base of fronto-orbital seta with a stripe (Fig. 1D); stripe on the middle of frons extending to ocellar triangle (Fig. 1C) H. (H.) nigrifacies group
– Base of fronto-orbital setae without a stripe; only costal margin of frons yellow (Fig. 1E) H. (H.) trispina group
10 Wing without spots on crossvein r-m (Fig. 3G) 11
– Wing with spots on crossvein r-m (Fig. 3E) H. (H.) quinquenotata group
11 R4+5 without spots between r-m and apical spot (Fig. 3E) H. (H.) pallida group
– R4+5 with spots between r-m and apical spot (Fig. 3D) H. (H.) henanensis group

Discussion

Our study proposes a phylogenetic relationship hypothesis for the genus and subgenus Homoneura using morphological data. In this study, five genera of Homoneurinae except for Homoneura were included for the purpose of serving as an outgroup. Previously, Kong et al. (2022) published the phylogeny of the Chinese subgenera of Homoneura based on morphological characters, and obtained the conclusion that the monophyly of the genus and subgenus Homoneura is not supported, and this conclusion is further verified in this study. Some relationships among genera are in close agreement with the literature, suggesting that traditional taxonomic characters are more reliable at the generic level. Although the non-monophyly of Homoneura was strongly supported, the position of the species groups across the subgenus Homoneura was less consistent.

Based on the increment of available morphological characters and on the result of our analyses, we propose to divide the subgenus Homoneura. This is different from the the method of dividing the subgenus Homoneura solely based on spots on the wing. Based on the resultant strict consensus tree we propose to reduce the 21 species groups into 12 species groups by establishing three new species groups: H. (H.) nigrifacies, H. (H.) pallida, and H. (H.) patella; keeping seven species groups: H. (H.) beckeri, H. (H.) formosae, H. (H.) henanensis, H. (H.) nigra, H. (H.) notostigma, H. (H.) ornatifrons, and H. (H.) trispina; and combining the remaining species groups into two new species groups: H. (H.) laticosta, and H. (H.) quinquenotata. However, we advise for caution since these possible placements are tentative at best and further studies are needed to verify these observations.

Previously, the only existing molecular phylogenetic study of the generic level relationships of Lauxaniidae, Shi et al. (2017) explored the phylogeny of the subgenus Homoneura based on two mitochondrial and two nuclear markers. But the results did not support the published taxonomy of the species groups of the subgenus Homoneura in China (Shi and Yang 2014). All of these indicates that there are many problems in the division of species group of the subgenus Homoneura. In our research, we provide solid evidence that the currently recognized genus and subgenus Homoneura are not monophyletic. Thus, our results indicate that the current classification of the Homoneura does not accurately reflect the evolutionary history of the group. This result is consistent with the results obtained by Shi and Yang (2014). We do not seek to formally propose one of these changes here because the resolution of these clades is poor and because our taxon sampling is limited (only Chinese species are involved). We can only try to separate species groups of the subgenus Homoneura. Furthermore, we need to take a closer inspection of the morphology, focusing on an alternative level of analysis. Therefore, in order to enable such taxonomic decisions, we urge for a complete phylogeny of the Homoneura with datasets including more morphological and molecular data.

Conclusions

Our research results show that the monophyly of the genus and subgenus Homoneura is not supported, and the confusion of the subgeneric division is one of the main problems of this genus, which makes some scholars ignore the subgeneric rank in their works, and there are often taxonomists who misclassify subgenera when describing species. The main reason is that the key characteristics and validity of subgeneric level classification are not clear. Although not the primary focus of this study, our results also provide a preliminary glimpse of potential major relationships within the genus Homoneura. Nevertheless, we emphasize that this study was focused on testing the monophyly and the relationships of the species groups within the subgenus Homoneura. Thus, our findings regarding the major relationships within the entire genus should be considered, at best, preliminary. And although these conclusions are based on a small sample size compared with the diversity of the genus as a whole, our results indicate that the classification of the genus at the subgenus and species group levels will require a thorough reformulation that reflects the family’s evolutionary history. In these cases, we should re-analyze the morphological data, trying to look for misinterpretations of morphological characters.

As a next step for the phylogeny and classification of the genus and the subgenus, we will try to find synapomorphies of early diverging lineages, whose phylogenetic placements are not well supported in our study. Additionally, the phylogeny of each subgenus of Homoneura is still unclear, and the monophyly and phylogenetic relationship of species groups is still blank, and none of them have been examined using molecular data. The availability of molecular data for species of Homoneura has increased during recent years, and we encourage the phylogenetic analysis among the species groups at the subgeneric level using a combination of morphological and molecular data. Furthermore, we will review specimens from other zoogeographical regions and revise the species groups of the Homoneura subgenera by using geographic distribution information to reconstruct the phylogeny of the genus Homoneura making taxonomic revisions.

Acknowledgements

We express our sincere thanks to Xulong Chen for identification of the specimens of Homoneura.

References

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Supplementary materials

Supplementary material 1 

The species studied

Author: Yao Yao

Data type: pdf

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
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Supplementary material 2 

Morphological dataset used for the analysis of the phylogeny

Author: Yao Yao

Data type: pdf

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
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Supplementary material 3 

Maximum parsimony tree

Yao Yao, Chaoyang Kong, Pu Miao, Shengjuan Zhao, Wenliang Li

Data type: zip

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (1.54 MB)
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