Research Article |
Corresponding author: Laura C.V. Breitkreuz ( l-breitkreuz@ku.edu ) Corresponding author: Shaun L. Winterton ( wintertonshaun@gmail.com ) Academic editor: Atilano Contreras-Ramos
© 2015 Laura C.V. Breitkreuz, Shaun L. Winterton, Michael S. Engel.
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:
Breitkreuz LCV, Winterton SL, Engel MS (2015) Revision of the green lacewing subgenus Ankylopteryx (Sencera) (Neuroptera, Chrysopidae). ZooKeys 543: 111-127. https://doi.org/10.3897/zookeys.543.6476
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The Australasian and Oriental green lacewing subgenus Ankylopteryx (Sencera) Navás (Chrysopinae: Ankylopterygini) is examined and its diversity and placement among other members of the tribe Ankylopterygini is discussed. After study of specimens spanning the full distribution and anatomical range of variation for the subgenus, all prior putative species, resulting in the sole valid species are newly synonymized, Ankylopteryx (Sencera) anomala (Brauer). Accordingly, the following new synonymies are established: Sencera scioneura Navás, syn. n., S. feae Navás, syn. n., and S. exquisita Nakahara, syn. n. [all under the name A. (S.) anomala]. A lectotype is newly designated for A. (S.) anomala so as to stabilize the application of the name. To support our hypotheses, the wing and general body coloration as well as the male genitalia are reviewed. We elaborate on the possibility of A. (S.) anomala being nothing more than an autapomorphic species of Ankylopteryx Brauer, as it was originally described. The species is not sufficiently distinct to warrant recognition as a separate subgenus within the group, and most certainly not as its own genus as has been advocated by past authors. Nonetheless, we do not for now go so far as to synonymize the subgenus until a more extensive phylogenetic analysis is undertaken with multiple representative species from across Ankylopteryx and other ankylopterygine genera. Lastly, we comment on the biology of A. (S.) anomala in terms of the attraction of males to methyl eugenol and on the widespread practice of splitting within Chrysopidae.
Ankylopterygini , Australasia, Oriental, Chrysopinae , lacewing, semiochemicals, taxonomy
The green lacewings (Chrysopidae) of the Australasian and Oriental regions comprise a diverse, yet poorly studied fauna (e.g.,
Here we present a brief review of the subgenus based on the most extensive sampling of these rare lacewings, and elaborate and expand upon Nathan Banks’ suspicions. Indeed, others have also noted similarities which, when taken into a broader context, suggest that it is not only the species that are suspect but the subgenus as a whole.
The higher classification followed is that of
In total we examined 49 specimens during the course of this study, which are deposited in the following institutions and were provided through the generosity of the named curators:
NHML
The
High-resolution photographs of historical type material that was otherwise not available for loan were contributed by the following:
Sencera
The subgenus Sencera differs from Ankylopteryxs.str. only in the absence of the forewing ‘im’ cell (Fig.
Ankylopteryx anomala
Sencera scioneura
Sencera feae
Sencera feai
Sencera exquisita
Ankylopteryx (Sencera) anomala Brauer:
Ankylopteryx (Sencera) scioneura (Navás):
Ankylopteryx (Sencera) feae (Navás):
Ankylopteryx (Sencera) exquisita (Nakahara):
Ankylopteryx exquisita (Nakahara):
As for the subgenus (vide supra).
♂. Overall color in live specimens light green with mostly greyish brown and some whitish markings (Fig.
Photographs of forewings of Ankylopteryx (Sencera) anomala (Brauer) 3 Lectotype male from Pulo Milu, Nicobar Islands, India (
Head: vertex smooth, raised and flat; laterally pale green, medially light green, with brown marking medially above toruli [varying in size and intensity of coloration from faint to dark, heart-shaped marking]. Frons smooth and flat; light green to whitish [in some specimens slightly darker than vertex] with small brown marking medially below toruli [varying in size and intensity of coloration from not visible to clearly visible marking (size about distance between toruli)]. Malar space broad; with brown marking extending from mandibular base to lower compound eye margin and epistomal sulcus. Clypeus smooth, slightly raised, indented medially at apical margin; medially light green to whitish, laterally and apically with brown marking. Labrum smooth, flat, apical margin simple without indentation, with brown markings basolaterally and apically. Mandible smooth, apex pointed; dark brown. Maxillary palp light green, fifth palpomere brown. Labial palp light green, third palpomere brown. Gena ventrally flat; light green [in few specimens with brown marking medially]. Scape short and broad (ca. 1.25 times as long as wide); light green to whitish with brown marking laterally [varying in size and intensity of coloration from absent to dark brown longitudinal band]. Pedicel short (ca. 1.1 times as long as wide); light green to whitish. Flagellomeres ca. 2.4 times as long as wide; light green to whitish; setae in 4 rows, long (varying within single flagellomere from as long as flagellum width to twice as long), brown.
Thorax: pronotum ca. 0.9 times as long as wide; light green with brown longitudinal marking anterolaterally [varying in size from spot anteriorly to stretching over 2/3 of pronotum and intensity of coloration from almost not visible to dark brown]; setae whitish, long. Meso- and metathorax light green laterally and ventrally, dorsally mostly brown-greyish with some light green and pale green [intensity of brown greyish markings varying]; setae whitish, microsetae dense, long setae sparse. Prescutum with more light green than brown-greyish in some specimens; setae whitish, microsetae dense, long setae sparse. Metascutum with whitish marking; setae whitish, microsetae dense, long setae sparse medioanteriorly. Postmetascutellum light green with small brown-greyish marking anteriorly; setae whitish, microsetae dense, long setae sparse.
Legs: light green, fifth tarsomere and pretarsal claws dark brown; most specimens with brown marking mediodistally on pro- and mesotibia [varying in size and intensity of coloration of marking from absent on both legs to well-defined dark brown spots on both legs, marking on mesotibia mostly smaller than on protibia]; setae long, mostly whitish, some brown. Pretarsal claws dilated basally.
Forewing (Figs
Photographs of forewings of Ankylopteryx (Sencera) anomala (Brauer) showing gradations in wing colouration, from almost unmarked (7), to slightly marked (8), to more strongly marked (9), and ultimately to very strongly marked (10). Specimens from Vanuatu (7), Brunei (8), Myanmar (9), and Hainan, China (10). All photographs by L.C.V.B.
Hind wing: narrow (ca. 3.5 times as long as wide), apically more strongly pointed than forewing. Veins mostly pale green [varying from almost all pale green to some veins brown at joints, only few veins completely brown]; setae pale [some setae partially brown, corresponding with wing markings]. Costal area narrow (ca. 0.11 times as wide as total wing width). Several r-rs (Rx) with brown markings surrounding vein (normally 6r-rs – 9r-rs) in most specimens, or only brown veins without surrounding marking; number of inner gradates varying from 3–5 (varies also between wings in same specimen); veins mostly brown; basal inner gradate meeting Psm; most specimens with brown marking surrounding base of inner gradates; number of outer gradates varying from 4–7 (also varies at times between wings in same specimen); veins mostly brown. Area between Cu2 and basal-most terminal branch Psc with brown marking [varying in size and intensity of coloration]. Light brown markings surrounding some terminal Psm branches in some specimens; some psm-psc with small light brown markings surrounding vein in some specimens, two apicalmost psm-psc brown in most specimens; junction of wing margin and veins brown in most specimens, especially in apical half of wing.
Abdomen: Terga light green with brown-greyish markings dorsally on terga IV–IX, markings broader on anterior terga. Sterna light green; sterna VIII+IX fused. Setae whitish, microsetae dense, long setae more sparse.
Genitalia (Figs
♀. Characters as in male except terminalia: Terminalia (Fig.
Based on average from 5 specimens: Head 0.74 times as long as wide; upper distance between compound eyes 1.22 times lower distance between compound eyes; clypeus 0.51 times as long as wide; labrum 0.52 times as long as wide; malar space 1.09 times as long as mandibular base is broad; scape 1.09 times as long as wide; pedicel 1.19 times as long as wide; flagellomeres 3.7 times as long as wide (measured medially on flagellum); thorax 1.43 times as long as wide (measured in dorsal view); pronotum 0.95 times as long as wide (measured in dorsal view); forewing 2.62 times as long as wide; forewing costal width 0.3 times width of forewing; hindwing 3.57 times as long as wide; terga 1.51 times as long as wide (average of third tergum, difficult to measure when dry).
Lectotype (here designated). ♂, [India], M, Novara [Reise], 1857–59, Milu, Nicob. (Fig.
♂, [India], O, Novara Reise, 1857–59, Sambelong, Nicob. [this is the second specimen referred to by
In addition to the syntype series, a total of 47 specimens available for study (21 ♂♂, 11 ♀♀, 15 sex undetermined), institutional repository and original identification of material indicated in square brackets: AUSTRALIA: 1♂, label imprecise: “Australia?”, date unknown; collector unknown [BMNH: originally as S. scioneura]. BRUNEI: 3♂♂, 1 sex indet., June 16th 1984, collector A. Saman, Triencide trap [BMNH: originally as S. anomala]. CHINA: 1 sex indet., Hainan, You Boi, 1911, collector unknown [BMNH: originally as S. exquisita]. INDIA: 1 sex indet., Pirmed, 3400 ft., May 4th–6th 1937, collector Travencore [BMNH: indet. #1]. INDONESIA: 1♀, Sulawesi, Utaria, October 1985, collector unknown, Project Wallace of the R. Ent. Soc. Lond. [BMNH: originally as S. anomala]. MALAYSIA: 1♂, 2 sex indet., Bettotan near Sandakan, individual dates of July 26th, July 30th, and August 3rd 1927, collectors C.B.K & H.M.P [BMNH: originally as S. anomala]; 2♂♂, 1 sex indet., Cameron Highlands, May 22nd 1983, Methyl Eugenol lure trap, collector R.A.I. Drew [
Although previous authors have alluded to other, putative species in Sencera (e.g.,
We compared the four nominal species in Sencera (A. anomala, A. exquisita, A. feae, and A. scioneura) as well as several undetermined specimens, some of which were considered putatively new species. Even at first glance over previously determined material it was evident that there is and has been a great amount of confusion when it comes to identifying specimens to one of the original four species. The species in Sencera were established on differences in wing coloration (Figs
Just as with wing coloration, the intensity of markings on the pronotum and whether a spot is present and the degree of its development on the protibia vary similarly. Some specimens from Brunei lack this protibial spot, in others it is small but present — suggesting that this character is almost as variable as the wing coloration. All other characters are similar to the remaining specimens and this missing spot is not mentioned in any description and does not seem to be indicative of an endemic ‘spotted-protibia species’. More importantly, we dissected the male genitalia from specimens representing the full spectrum of coloration and found no significant differences among them. The genitalia of some specimens are slightly thicker but these are exceedingly small variations and seem to be correlated with body size and degree of pigmentation rather than any boundary between taxa. Accordingly, there are no discrete units identifiable across the variation observed, and our larger sample sizes are indicative of a single, widespread, and variably-colored species. This has served as the basis for our aforementioned synonymies.
Not only has the similarity of those previously recognized species within Sencera been striking, but also the dramatic sameness of the subgenus and Ankylopteryxs.str. As mentioned in the original description of Sencera, the only difference between these groups is the absence of the im cell (
The synonymy of the four species of Sencera discussed here begs mention of an issue common to the taxonomy of lacewings. Within Chrysopidae there are a vast number of species and genera that are characterized by exceptionally small differences in trifling traits by comparison to their closest relatives, and such supraspecific groups are frequently monotypic (
Males of Sencera are attracted to methyl eugenol (IUPAC: 1,2-Dimethoxy-4-prop-2-en-1-ylbenzene) (
Hitherto, the known number of chrysopid taxa attracted to methyl eugenol is low. Apart of Sencera it has been shown to attract only Mallada basalis (Walker) in Hawaii (
Such observations raise many questions, including whether or not such a chemical association is pervasive across the clade comprising Parankylopteryx, Ankylopteryxs.str., and Sencera, and whether such attraction might even represent a synapomorphy for this or a more inclusive group. It is important to investigate whether males of species of Ankylopteryx are attracted to this chemical and if this can be found throughout Ankylopterygini. More importantly, it remains to be discovered what the true biological significance of this trait is. Given that the baits only attract males, one immediately wonders whether these are components of semiochemicals produced by the females or if they play some other role in courtship and mating behaviors (
We are grateful to three reviewers for their comments on the manuscript, and to the aforementioned curators who kindly supplied material for this study, or who graciously provided high-resolution photographs of fragile historical material, and/or for hosting L.C.V.B. during visits to their institutions in 2014–2015. We are also thankful to P.T. Ong for allowing us to reproduce here his photograph of A. anomala at a flower of Bulbophyllum (as figure 14). We dedicate this small project to the memory of Maurice J. Tauber (1931–2014), who contributed much to the knowledge of chrysopid biology and evolution, was a wonderful guide to M.S.E. during his time at Cornell, and a wonderful colleague to us all. His presence in neuropterology shall be missed. This work has been supported by U.S. National Science Foundation grants DEB-1144162 (to M.S.E.) and DEB-1144119 (to S.L.W.). Statements and viewpoints expressed herein do not necessarily reflect the opinion of NSF. This is a contribution of the Division of Entomology, University of Kansas Natural History Museum.