First record of the genus Empidideicus Becker, 1907 (Diptera, Mythicomyiidae) in China and the Oriental Region, with description of a new species

Abstract Abstract

Empidideicus Becker, 1907 is newly recorded from China and the Oriental Region, with one new species, E.pentagoniussp. n., described and illustrated. Observations are provided on the biology of E.pentagoniussp. n. visiting flowers of Stemonamairei (Levl.) Krause (Liliflorae, Stemonaceae). A key to the genera of Mythicomyiidae known to occur in China is provided.

Introduction

Mythicomyiidae is a cosmopolitan family in the Bombylioidea with more than 330 described species in 25 extant genera from six subfamilies (Evenhuis 2002). This family has the greatest diversity in semi-arid and arid regions and is strongly associated with flowers. Hitherto, only three genera of Mythicomyiidae have been reported from China: Mythenteles Hall & Evenhuis, 1986, Cephalodromia Becker, 1914, and Platypygus Loew, 1844.

Empidideicus Becker, 1907 belongs to the monogeneric subfamily Empidideicinae. So far, 42 species have been described, with 20 species distributed exclusively in the Afrotropical Region and 20 species distributed exclusively in the Palaearctic Region, and two species are distributed in both Afrotropical and Palaearctic regions (Evenhuis 2002, 2007, 2009; Gharali et. al. 2010, 2011, 2015; Hakimian et. al. 2014). The tribe Empidideicini was established by Hull (1973) within the Mythicomyiinae, when he first introduced tribal-level classification into Bombyliidae. Initially four genera, Empidideicus Becker, 1907, Anomaloptilus Hesse, 1938, Euanthobates Hesse, 1965, and Leylaiya Efflatoun,1945, were included in Empidideicini. Recent studies have focussed on the Afrotropical fauna (Evenhuis 2009, 2007), and described 10 new species of Empidideicus in Iran (Gharali et. al. 2010, 2011, 2015; Hakimian et. al. 2014).

The genus Empidideicus is reported from China and Oriental Region for the first time, and a new species, E.pentagonius sp. n., is described. Observations are provided on the flower visiting behaviour of E.pentagonius in northwestern Yunnan, China. A key to the genera of Mythicomyiidae from China is presented. The distribution of the new species updates the easternmost distribution of the genus and more species might be distributed in the dry-hot valleys of the Oriental and eastern Palaearctic regions.

Material and methods

Specimens were collected by sweeping flowers of Stemonamairei (Levl.) Krause in June beside the Jinsha River in southwest China (28°21'18.91"N, 99°12'52.20"E). The photos of adults visiting flowers were taken with a Canon 5D digital Camera and combined into figures using Adobe Photoshop CS3 software. Photos of male genitalia were taken by KEYENCE VHX-2000. The specimens were studied and illustrated with an Olympus SZ61 stereo microscope. Preparations of genitalia were made by macerating the apical portion the abdomen in cold 10% NaOH for 12–15 h. After examination, dissected material was transferred to fresh glycerine and stored in a microvial together with the specimen. The holotype and other specimens examined are deposited in the Entomological Museum of the China Agricultural University, Beijing (CAU).

Taxonomy

Key to genera of Mythicomyiidae from China

1	Wing vein R2+3 absent	2
–	Wing vein R2+3 present	3
2	Wing m-cu crossvein present; female spermathecae spherical with apical invagination	Empidideicus
–	Wing m-cu crossvein absent; female spermathecae reservoir conical	Mythenteles
3	Wing cell dm open distally, not closed by crossvein	Cephalodromia
–	Wing cell dm closed distally by crossvein	Platypygus

Genus Empidideicus Becker

EmpidideicusBecker 1907: 97. Type species: Empidideicuscarthaginiensis Becker, 1907, by monotypy.

CyrtoidesEngel 1933: 102 (as subgenus of Empidideicus Becker). Type species: Empidideicusefflatouni Engel, 1933, by monotypy.

EclipticaEngel 1933: 103. Unavailable name; name proposed in synonymy with Cyrtoides and not made available before 1961.

AnomaloptilusHesse 1938: 983 (as subgenus of Empidideicus Becker). Type species: Empidideicuscelluliferus Hesse, 1938, by monotypy.

AetheoptilusHesse 1967: 112 (as subgenus of Empidideicus Becker). Type species: Empidideicuszuluensis Hesse, 1967, by original designation.

Empidideicus pentagonius sp. n.

http://zoobank.org/5BA3F89D-BC77-4EA0-A116-CAE9501157D5

Figures 5 , 6–9 , 10–11

Figures 2–5.

2–4 Photographs of Empidideicuspentagonius sp. n. visiting Stemonamairei5 adult of Empidideicuspentagonius sp. n. Photographs in nature by Yan Qin.

Figures 6–9.

Photographs of male genitalia and wing of Empidideicuspentagonius sp. n. 6 phallus and gonocoxa, dorsal view 7 phallus and gonocoxa, lateral view 8 epandrium, ventral view 9 wing.

Figures 10, 11.

Empidideicuspentagonius sp. n. 10 Thorax, dorsal view 11 Antenna, dorsal view.

Diagnosis.

Head with ocellar tubercle yellowish, frons and face yellowish with a cup-shaped brown area between frons and face; thorax with two yellowish subtriangular marks anterolaterally, with a subtrapezoidal yellowish brown area posteriorly; katepisternum with upper 1/3 yellow; aedeagal apodeme base semicirclular, with acute tip in dorsal view, aedeagal apodeme arched in lateral view; epiphallus pentagonal, with narrow tip in dorsal view.

Description.

Male. Body length 0.8–1.4 mm, wing length 1.1–1.4 mm.

Head black and yellowish, eyes red, bare; ocellar tubercle black, ocelli yellowish; eyes dichoptic, 2 × width of ocellar tubercle, frons and face bare, yellowish, except a cup-shaped brown area between frons and face; occiput black. Antenna (Fig. 11) yellowish brown, scape semicircular nearly twice wider than long; pedicel trapezoidal, slight wider than long; first flagellomere ovoid, nearly 1.7 × longer than wide; second flagellomere about 1/3 length of first flagellomere, cylindrical, about 3 × longer than wide, with minute apical style. Antennal ratio: 1:2:8. Proboscis brown except base with a yellowish quadrilateral area laterally, nearly 2 × length of head.

Thorax (Fig. 10) black and yellowish, mesonotum mostly black except edge yellowish, postpronotal lobe yellowish, anterior with two yellowish subtriangular marks laterally, and a subtrapezoidal yellowish brown area posteriorly, mesonotum with three brown prealar bristles, anepisternum and anepimeron mostly yellow except edge of front and bottom black, katepisternum mostly black except upper 1/3 yellow.

Scutellum yellowish brown. Legs yellow except femora and tarsi brown. Legs with short brown hairs; tibiae with short black hairs and bristles, tarsi with short black hairs.

Wing (Fig. 9) hyaline, except veins brown. Wing length 2.3 × width, wing with veins R₁, R₄₊₅, M₁, M₂, M₁₊₂, CuA and Cup present, Sc incomplete; Costa, Sc, R₄₊₅ and CuA₂ strongly sclerotized, vein M₁, M₂, M₁₊₂ and CuA₁ less sclerotized; vein R₁ ending nearly in middle of costa, R₄₊₅ slightly curved anteriorly, M₁ and M₂ form an acute angle, crossvein r-m at bottom of cell dm. Wing with tiny hairs at margin. Halteres yellowish, except edge of tip brown.

Abdomen with all tergites dark brown, except posterior margin with narrow pale brown band, and with yellow posterolaterally. Sternites yellowish mostly, except yellowish brown centrally, and pale laterally.

Male genitalia brown and black (Figs 6–8). Epandrium brown except edge black, nearly as long as wide, cercus well exposed, narrow and long, tip acutely in ventral view; gonocoxa L-shaped, nearly 2 × longer than wide, with acute tip, gonostylus triangular with acute tip in lateral view; aedeagal apodeme base semicircle, extremely long, and narrowly apically, with acute tip in dorsal view, aedeagal apodeme arch in lateral view; epiphallus pentagonal, with narrow tip in dorsal view, epiphallus tip sickle-shaped in laterally view.

Female. Body length 1.2–1.7 mm, wing length 1–1.2 mm. Female genitalia (Figs 12, 13) furca subtriangular, 1.7 higher than wide, with concavity at middle of bottom; spermathecal bulb subglobular when viewed on edge, nearly rectangular in lateral view, invaginated apically, subquadrate in form, slightly wider than deep in lateral view.

Figures 12, 13.

Female genitalia of Empidideicuspentagonius sp. n. 12 Female genitalia 13 spermathecal bulb.

Type material.

Holotype male, CHINA: Yunnan Deqin Benzilan (28°21'18.91"N, 99°12'52.20"E), 08–18. XI. 2017, Yan Qin; Paratype female, CHINA: Yunnan Deqin Benzilan (28°21'18.91"N, 99°12'52.20"E), 08–18. XI. 2017, Yan Qin; 29 males 12 females, CHINA: Yunnan Deqin Benzilan (28°21'18.91"N, 99°12'52.20"E), 08–18. XI. 2017, Yan Qin.

Distribution.

China (Yunnan).

Etymology.

The specific name refers to the epiphallus pentagonal in dorsal view.

Remarks.

The new species is similar to E.legulicoxa Gharali & Evenhuis, 2010 (Iran), but it can be separated from the latter by the following features: the frons and face are yellowish, except a cup-shaped brown area between frons and face; the katepisternum mostly black except for the upper 1/3, which is yellow; the abdomen with all tergites is dark brown, except the posterior margin, which has a pale brown narrow band, and laterally, which is yellow posteriorly. In E.legulicoxa, the frons is yellowish white, and slightly depressed medially with a large squarish brown spot medially, and the lower 3/4 of the katepisternum is yellowish white; the abdomen is predominantly yellow and with medial brown color dorsally, tergites I–III are brown with undulating posterior margins (Babak et al. 2010).

Observations

Empidideicuspentagonius sp. n. is one of the most important pollinators for Stemonamairei (Levl.) Krause in southwestern China (Fig. 1) (Yan Qin personal observation). During the collection of the specimens, the following observations were made by Yan Qin (Yan Qin 2018): (1) E.pentagonius sp. n. rests on the flowers of Stemonamairei for a few minutes to half an hour, apparently feeding pollen or nectar. (2) After visiting a flower, much pollen was observed on the body of flies, which visited one flower after another. (3) E.pentagonius sp. n. is considered an important pollinator of S.mairei in June, but this species is rare in July, and beetles became the dominant visitors of S.mairei instead. (4). Different from other species of Stemona, S.mairei has a faint fragrance instead of a rotting smell (Chen et. al. 2017), which might attract E.pentagonius. (5) The eggs and larvae of the flies were not found in the flower, and the life history of E.pentagonius is unknown (Figs 2–5).

Figure 1.

The location of the specimens of Empidideicuspentagonius sp. n. collected.

Acknowledgements

We are very grateful to Yan Qin (Kunming) for collecting the specimens. Our thanks also go to Dr Babak Gharali (Tehran) and Dr Neal Evenhuis (Honolulu) for providing important references and for their great help in the study. Thanks to Xuankun Li (Canberra) for comments on a draft of the paper, as well as Allan Cabrero (Berkeley) and Xuankun Li (Canberra) for suggestions and comments on a draft of the paper. Support for this study was provided by grants from the NSFC-Yunnan joint fund to support key projects to G. Chen (grant no. U1602264) and National Natural Science Foundation of China (no. 31301670) as well as China Postdoctoral Science Foundation to Gang Yao (no. 2015M581205).

Citation

Yao G, Chen G (2019) First record of the genus Empidideicus Becker, 1907 (Diptera, Mythicomyiidae) in China and the Oriental Region, with description of a new species. ZooKeys 846: 65–73. https://doi.org/10.3897/zookeys.846.30391

Funding Statement

NSFC-Yunnan joint fund to support key projects