Philosina nigromacula Yu & Jin, 2024
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publication ID |
https://doi.org/10.48156/1388.2024.1917301 |
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persistent identifier |
https://treatment.plazi.org/id/591DFF6D-8A6B-FFE4-7271-AEAF6AB8FA65 |
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treatment provided by |
Felipe |
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scientific name |
Philosina nigromacula Yu & Jin |
| status |
sp. nov. |
Philosina nigromacula Yu & Jin , sp. n.
Material
1 male (Holotype), Dazhou , Sichuan, China, 27 May 2024, Xin Yu leg. (in College of Life Sciences of Chongqing Normal University) ; 2 males, same locality, date and collector ; 2 males and 1 female, Wuyuan , Jiangxi, China, 30 May 2022, Hongguang Jin leg. (paratypes) .
Etymology
The specific epithet nigromacula means black mark, indicating the striking blackish abdomen segment 7 in males ( Fig. 1 b View Figure 1 , Fig. 2 a–e View Figure 2 ). A noun in apposition.
Description of holotype male
Head. Labium brown. Labrum, bases of mandibles, genae, and frons bluish-green. Base of labrum with a black cross stripe. Anteclypeus, postclypeus, and top of head matt black with a narrow pale colored cross stripe between eyes just behind lateral ocelli. Antennae wholly black. Postocular spots yellow, stripe-like.
Thorax. Prothorax black, strongly pruinosed, two yellow stripes at upper lateral margin. Synthorax black, strongly pruinosed, with broad yellow antehumeral stripes which are interrupted at upper end. A short and narrow yellow stripe just below the mesopleural suture. Metathorax yellow with broad black stripe, that covers metapleural suture. A short and thin yellow stripe just below the metapleural suture. Legs wholly black; coxae, trochanters and femora finely pruinose. Wings hyaline with dark brown spots at each wing apex, pterostigma dark brown, not braced, covering four cells.
Abdomen. Predominantly black, with narrow yellow lateral stripes on each segment. All abdomen segments strongly pruinose except segment 7, which show the black color. Caudal appendages black with fine pruinosity on dorsum of superior appendages. Superior appendages strong, forcipate, twice as long as segment 10. Inferior appendages reduced, with short and acuminate tips bending upward. Genital ligula end with a pair of flagella-like lateral lobes and a large transparent foliate sack ( Fig. 3 b, c, e, f View Figure 3 ).
Measurements (mm). HW 36.7; abdomen + appendages 42.2.
Description of female paratype (Wuyuan, Jiangxi)
Head. Labium, labrum, base of mandibles, genae and frons yellow. Anteclypeus, postclypeus and top of head matt black, with a narrow yellow cross stripe between eyes just behind lateral ocelli. Antennae wholly black. Postocular spots yellow, stripe-like.
Thorax. Prothorax wholly black, with two yellow stripes at upper lateral margins. Synthorax black dorsally except a narrow yellow dorsal carina stripe, with an obvious yellow antehumeral stripe and a very short and narrow yellow stripe on the upper side of mesepisternum. Yellow laterally, with a black stripe that covers the metapleural suture. Legs black with yellow stripes on outsides and extensor surfaces of femora. Wings hyaline with very small dark brown dots at each wing apex, pterostigma dark brown, not braced, covering four cells.
Abdomen. Black with pale color stripes as below. Segment 1 yellow laterally. Segments 2 to 7 with yellow lateral stripes and middle dorsal lines. Segment 8 laterally with a yellow dot and a middle line at dorsal anterior 3/4. Segments 9–10 greenish-yellow dorsally. Caudal appendages black. Ovipositor robust, not extending to the end of abdomen ( Fig. 2 f View Figure 2 ).
Variation in male paratypes
Measurements (mm). HW 37.1–40.3; abdomen and appendages 43.1–45.2. The density of pruinosity increases with maturity ( Fig. 2 a–e View Figure 2 ). A pair of thin red colored lateral stripes present on S 7 in some individuals, which show large variation, from distinct moderately wide stripes gradually paling to completely absence. Howev- er, presence or otherwise and distinctness or obscureness of the red stripe seem to have nothing to do with either maturity or population ( Fig. 2 a–e View Figure 2 ). Antehumeral stripes are complete in some individuals ( Fig. 2 a, c, f View Figure 2 ) but interrupted at upper end in others ( Fig. 2 b, d, e View Figure 2 ), and the degree of interruption is variable.
Diagnosis
Philosina nigromacula generally resembles P. buchi in its body colors and size, but differs in the marks on abdomen of males. The dorsum and sides of abdomen segments 7–9 are wholly bright red in P. buchi whereas segments 8–9 are pruinosed and segment 7 is black, sometimes, with red lateral margins in P. nigromacula ( Fig. 2a–c View Figure 2 ). Philosina alba has an obviously smaller body size compared to the other two species and also lacks any marks on the abdomen in mature males ( Fig. 1 View Figure 1 ). Both P. nigromacula and P. buchi possess a sack structure on the tip of the male ligula which is absent in P. alba ( Fig. 3 View Figure 3 ).
Habitat
The Wuyuan population was found in a 10 m wide montane stream with running water at an altitude of 1050 m, surrounded by very dense riparian vegetation ( Fig. 4 View Figure 4 ). Also occurring in the same area were Philogan ga robusta Navás, 1936, Pseudocopera annulata (Selys, 1863) , Euphaea decorata Hagen in Selys, 1853, Archi neura incarnata (Karsch, 1892), Gomphidia confluens Selys, 1878 , and Orthetrum luzonicum (Brauer, 1868) . The Dazhou population was found in a 40 m wide slowly flowing river at an altitude of 230 m, by dense bankside vegetation ( Fig. 5). Also occurring in the same area were Pseudothemis zonata (Burmeister, 1839) , Deielia phaon (Selys, 1883) , Orthetrum albistylum (Selys, 1848) , Sympetrum eroticum (Selys, 1883) , Paracercion calamorum (Ris, 1916) , Ceriagrion nipponicum Asahina, 1967 , Agriocnemis femina (Brauer, 1868) , and Platycne mis phyllopoda Djakonov, 1926.
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