Research Article |
Corresponding author: Yongjie Wang ( wangyjosmy@gmail.com ) Corresponding author: Zhiqi Liu ( liuzhiqi@cau.edu.cn ) Academic editor: Atilano Contreras-Ramos
© 2017 Han Xu, Shaun L. Winterton, Yongjie Wang, Zhiqi Liu.
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:
Xu H, Winterton SL, Wang Y, Liu Z (2017) Two new species of Thyridosmylus Krüger, 1913 from Madagascar (Neuroptera, Osmylidae). ZooKeys 724: 43-52. https://doi.org/10.3897/zookeys.724.21057
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The lance lacewing genus Thyridosmylus Krüger (Osmylidae: Spilosmylinae) is found in Madagascar and Southeast Asia. Two new Malagasy species are described herein, Thyridosmylus fuscomarginatus Xu, Wang & Winterton, sp. n., and Thyridosmylus longiprocessus Xu, Wang & Winterton, sp. n. A key to differentiate the Malagasy species of Thyridosmylus is provided.
lacewing, Malagasy species, Osmylidae
Thyridosmylus Krüger is a small genus of lance lacewings assigned to the subfamily Spilosmylinae.
Presently there are 19 species described in Thyridosmylus, including 17 species from South East Asia and two from Madagascar, suggesting the conspicuously disjunct geographical distribution (
The Malagasy Thyridosmylus species have been mentioned seldom in the literature since their description. Based on recently collected material from Madagascar, two new species are described, Thyridosmylus fuscomarginatus Xu, Wang & Winterton, sp. n. and Thyridosmylus longiprocessus Xu, Wang & Winterton, sp. n.
The specimens observed in this study are deposited in the California Academy of Science, San Francisco (
Thyridosmylus Krüger, 1913: 87. Type species: Osmylus langii McLachlan, 1870: 197. Original designation. Type locality: Masuri (India).
Centrolysmus Navás, 1917: 15. Type species: Osmylus perspicillaris Gerstaecker, 1884: 46. Original designation. Type locality: Darjeeling (India).
Medium sized species (forewing length 13–24 mm), wings narrow (maximum width of forewing 4–7 mm). Ocelli present. Forewing strongly patterned with distinctive fenestrate spots close to the outer gradate series, with numerous suffusions, some of these forming a large macula, numerous crossveins. Costal crossveins simple, subcostal space with single crossvein. At least two distinct gradate series. Area between M and Cu lacking crossveins between them basally, thus a large cell is present. Hindwing with Cu forked at base, CuP short and not pectinate. Male ectoproct bearing a dorsal digitiform projection, gonarcus symmetrical, amalgamated distally, sclerotized marginally; baculum present; mediuncus C-shaped, linked by membranes; parameres present. Female genitalia with sternite 8 small, gonapophyses 9 as paired sclerites closely associated with gonocoxites 9, spermatheca simple or with a complicated lobed morphology.
Body length 10–15 mm. Head brown or dark brown; antennae yellow and shorter than or equal to half of length of forewing, scape and pedicel dark brown, flagellum yellow; compound eyes black; ocellar tubercles yellowish to brown; labrum brown or dark brown. Thorax dark brown with long setae; meso- and metathorax dark brown. Legs yellow with brown setae. Forewing length 13–24 mm, width 4–7 mm. Forewing generally with characteristic fenestrate spots near the outer gradate series and with numerous fuscous markings, membrane hyaline or with light infuscate suffusion; pterostigma brown with a light brown centre; two nygmata as brown spots; venation brown, some cross-veins edged with brown markings; costal cross-veins simple and occasionally bifurcate; cross-vein sc-r1 close to the base of forewing; forewing Rs with 10–15 branches, cross-veins among Rs branches forming more than two series of gradates; basal mp-cu cross-vein only one, forming a large cell. Hindwing length 12–22 mm, width 4–7 mm. Hindwing generally hyaline with few spots; pterostigma light yellow; nygmata inconspicuous and light brown; base of MP with a spur. Male genitalia. Tergite 8 and sternite 8 approximately quadrate. Tergite 9 commonly narrow, sternite 9 approximately trapezoidal or triangular; ectoproct with a dorsal process, callus cercus round; gonarcus sclerotized marginally, symmetrical and fused distally and base connected with a goblet-shaped anterior apodeme; entoprocesses bent in middle; mediuncus lobes bent into C-shape laterally and fused at base; parameres arch-like with medial thickening and invariant within genus. Female genitalia. tergite 8 broad and approximately quadrate; sternite 8 reduced and small; tergite 9 narrow and commonly constricted in middle articulated with gonopophysis 9 + gonocoxite 9; gonocoxite 9 finger-like in lateral view; each spermatheca connected with a spermathecal duct.
The distinction between the closely related Thyridosmylus and Spilosmylus has been historically ambiguous, although their reciprocally monophyletic sister-group relationship was confirmed in the phylogeny of the family by
The forewing of Thyridosmylus has two m-cu cross veins between the stem of the medial vein (before the split into MA and MP) and cubital vein to form single large cell, while the forewing of Thaumatosmylus has few fuscous spots, and three m-cu cross veins to form two basal cells. Also, the spermathecae in females of Thyridosmylus are elliptical or multilobed while the spermathecae in Thaumatosmylus tend to be large with a basal club-like sac, or with a small and apical finger-like to ovoid sac. Although the definition of genus Glenosmylus has been obscure since it was erected by
1 | Outer margin of forewing with extensive fuscous markings with a distinct fenestration around the outer gradate cross veins (Fig. |
Thyridosmylus fuscomarginatus Xu, Wang & Winterton, sp. n. |
– | Outer margin of forewing extensively marked but lacking distinct fenestration near outer gradates | 2 |
2 | Hindwing with series of small dark spots along the posterior margin towards the wing apex | Thyridosmylus punctulatus (Navás, 1933) |
– | Hindwing without series of spots along posterior margin towards the wing apex (Fig. |
3 |
3 | Basal half of forewing with two brown bands (Fig. |
Thyridosmylus longiprocessus Xu, Wang & Winterton, sp. n. |
– | Forewing without brown band-like markings | Thyridosmylus marmoratus Fraser, 1955 |
Pronotum light yellow with three longitudinal dark brown stripes; posterior margin of forewing with brown markings, branches of vein A1 marked with a dark brown spot, area around outer gradate cross-veins fenestrate with pale venation; sternite 8 in female reduced, extending anteriorly to form a forward process in lateral view; spermatheca complex with 11–12 sacs, basal sac large.
Head. Vertex yellowish-brown with black setae; compound eyes black, ocelli yellow, each one anteriorly edged with a black spot. Antennal flagellum light yellow with dark yellow apex; scape and pedicel light yellow; frons brown. Thorax. Pronotum light yellow with a dark brown longitudinal stripe in middle and parallel two dark brown markings on both sides, three markings linked by a latitudinal light brown stripe; meso- and metanotum brown. Legs. Yellow with brown setae; claws brown. Wings (Fig.
Thyridosmylus fuscomarginatus Xu, Wang & Winterton, sp. n. Male : a, b abdomen terminalia, lateral view (a) and dorsal view (b) c parameres, dorsal view d–e gonarcus, lateral view (d) and dorsal view (e) f ,g mediuncus, lateral view (f) and dorsal view (g). Female: h spermatheca i abdomen terminalia, lateral view. Scale bars: 0.2 mm.
Holotype. Female. MADAGASCAR: Mahajanga Prov., Parc National de Baie de Raly, 12.4 km, 337° NNW Soalala, elev. 10 m, 16°00'36"S, 45°15'54"E, 26–30.xi.2002, coll. Fisher, Griswold et al., collected at night, tropical dry forest (
The specific name “fuscomarginatus”, a compound from Latin fusco- (fuscus) and marginatus- (margin), in reference to the colour and pattern of markings on the outer and posterior margin of forewings.
Madagascar (Antsiranana, Mahajanga)
The forewings markings of Thyridosmylus fuscomarginatus sp. n. are characteristic, clearly differed from other Thyridosmylus species by the dark posteromarginal stripe.
Frons brown with two dark brown markings; forewing hyaline, basal half with two brown stripes; male genitalia with ectoproct bearing a long dorsal rod-like process; distal part of gonarcus with abundant pilosity; basal part of mediuncus laterally with heart-shaped structures in dorsal view; spermatheca complex, with 13 sacs, basal one small and oval.
Head. Vertex brown with black setae; compound eyes grey, ocelli yellow, base edged with a dark brown spot. Antennal flagellum yellow; scape and pedicel brown; frons brown with two dark brown markings. Thorax. Pronotum black; meso- and metanotum brown with a longitudinal dark stripe in middle. Legs. Legs yellow with brown setae; claws brown. Wings (Fig.
Thyridosmylus longiprocessus Xu, Wang & Winterton, sp. n. Male : a abdomen terminalia, lateral view; b, c gonarcus, lateral view (b) and dorsal view (c) d, e mediuncus, lateral view (d) and dorsal view (e) f, g parameres, dorsal view (f) and lateral view (g). Female: h abdomen terminalia, lateral view i spermatheca. Scale bars: 0.2 mm.
Holotype. Male. MADAGASCAR: Fianarantsoa Prov., S. E. Fandriana Korikory, elev. 1670 m, 20°23'S, 47°40'E, 13.iii.2002, coll. Michael E. Irwin & Evert I. Schlinger (
Thve specific name “longiprocessus”, a compound from Latin longi- (long) and processus- (process), which refers to the long dorsal process of ectoproct in male.
Madagascar (Fianarantsoa).
The male genitalia are not well sclerotized probably because it was teneral when it was collected. The sternite 8 in T. longiprocessus sp. n. is reduced into a sclerite without processes and the spermatheca is complex, consisting of 13 sacs, of which, the basal one is small and oval. Moreover, the dorsal process of ectoproct in male is quite long, clearly distinguished from other Thyridosmylus species, in which it is inconspicuous when it is observed in lateral view.
We thank Dr. Brian L Fisher and Dr. Hu Li for providing specimens for examination. This research was supported by the National Natural Science Foundation of China (Grants 31272352, 31301905 and 41372013), the Beijing Natural Science Foundation (Grant 5132008), Ph.D. Programs Foundation of Ministry of Education of China (Grant 20131108120005) and the United States National Science Foundation (DEB1144119).