Research Article |
Corresponding author: Axel Gruppe ( gruppe@wzw.tum.de ) Academic editor: Susanne Randolf
© 2020 Ulrike Aspöck, Horst Aspöck, Axel Gruppe.
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:
Aspöck U, Aspöck H, Gruppe A (2020) Anchored between heaven and earth – a new flightless brown lacewing from Peru (Neuroptera, Hemerobiidae). Deutsche Entomologische Zeitschrift 67(2): 141-149. https://doi.org/10.3897/dez.67.56008
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Male and female of Nusalala peruana sp. nov., a flightless hemerobiid from the Andes mountain range of northern Peru, at a height of almost 4000 m, are described, figured and documented as the first record of a brachypterous, flightless species of Nusalala Navás, 1913, from this country. The other two congeneric, brachypterous species are from high altitudes in Colombia and Costa Rica and have been described in the male sex only – the females remain unknown. The coriaceous domed forewings are shared by all three brachypterous Nusalala species. The ribbon-like hindwings of the male of N. peruana sp. nov. are unique, since those of the other brachypterous males are scale-like, as are the hindwings of the female of N. peruana sp. nov. Distribution and evolutionary backgrounds of brachyptery and flightlessness in Neuropterida are discussed.
Nusalala peruana sp. nov., coriaceous wings, brachyptery, flightlessness, high altitude
Camouflaged as a beetle? Not at all! It is a strategy high up in the mountains against being blown away by the wind. Flightlessness as a virtual anchor in both sexes.
Wing reduction and flightlessness are rare phenomena in Neuropterida and have diverse backgrounds. In the order Raphidioptera, females of two inocelliid species – Inocellia fulvostigmata H. Aspöck & U. Aspöck, 1968, and Indianoinocellia mayana U. Aspöck, H. Aspöck & Rausch, 1992 (H.
In the order Neuroptera, the rare examples of reduced wings and/or flightlessness are found scattered amongst the various families and most have been listed by
Recently, a new species of the genus Adamsiana (Ithonidae), described from Guatemala (
The family Hemerobiidae comprises 11 brachypterous species (
In the present paper, a new species of the genus Nusalala Navás, 1913, is described. It is the third brachypterous species discovered in the genus and, quite remarkably, it was found in both sexes. The other two brachypterous species, N. andina Penny & Sturm, 1984, from Colombia and N. brachyptera Oswald, 1997, from Costa Rica, are known from the males only. One Nusalala female is placed provisionally in N. brachyptera, but it is not designated as paratype and remains, in fact, undescribed (
The flightlessness of Nusalala peruana sp. nov. is discussed in the context of its ecological niche and systematic position.
All specimens were collected in yellow pan traps, which were laid out on the grass. The pans contained water with hair shampoo and were checked after 24 hours. After cleaning the insects in water, they were transferred to a container with 70–96% ethanol. After transport to the lab, the specimens were removed from alcohol and mounted with glue on stripes of stiff paper.
Genitalic preparations were made by clearing the apex of the abdomen in cold potassium hydroxide (KOH) (approx. 10% in water) for five hours. After rinsing off the KOH with distilled water, the apex of the abdomen was transferred to glycerine for further examination.
Photographs were taken with a Leica DFC camera attached to a Leica MZ16 binocular microscope and processed with the help of Leica Application Suite. They were then stacked with Zerene Stacker 64-bit and processed with Adobe Photoshop Elements 8.
Terminology of the genitalia follows U. Aspöck and H. Aspöck (2008).
The new species can be differentiated from most other species of Nusalala Navás, 1913, by the following combination of characters: Forewings coriaceous and domed, covering legs and body (Figs
(Figs
Thorax : Pronotum shield-like, blackish-brown, with dense brownish pilosity. Legs brownish, only tarsalia yellowish. Each leg with two simple apical claws.
Forewings with significant concavo-convexity, heavily domed, length of domed wings 3.6 mm, length of spread (flattened) wing 3.8 mm, width 1.9 mm, coriaceous, suboval, apically slightly tapered; densely covered with short hairs; colouration spotted brownish with white markings and a brownish stripe in the middle of the wing, which is proximally accompanied by a whitish stripe; colouration, however, extremely variable. Venation variable and irregularly reduced in some specimens. Costal space proximally broad, veins irregularly connected with small interjacent veins, no pterostigma discernible; subcostal space with a few irregular cross veins; radius with 3–5 radial branches; gradate series of radial space not clearly discernible; bases of radius and media fused; venation of median, cubital and anal spaces not clearly ascertainable. Hindwings ribbon-like, length 2.7 mm, width 0.4 mm, with a short, oblique subcosta (?) basally. Longitudinal veins branched, cross veins absent.
Male genitalia
(Figs
Nusalala peruana sp. nov., paratype, male (from Hualgayoc). 8. genital sclerites, lateral; 9. genital sclerites, ventral; 10. genital sclerites, lateral, partly dissected; 11. genital sclerites, dorsal, partly dissected; e – ectoproct; gp10 – gonapophysis 10; gst9 – fused gonostyli 9; gx9 – gonocoxite 9; gx10 – partly fused gonapophyses 10; hi – hypandrium internum; S – sternite; T – tergite.
Description of the female paratype (Figs
Nusalala peruana sp. nov., paratype, female (from Hualgayoc). 12. habitus, dorsal with right forewing (left forewing missing) and left scale-like hindwing; 13. scale-like left hindwing; 14. head, frontal; 15. genital sclerites, lateral; 16. genital sclerites, ventral; e – ectoproct; gp8 – gonapophysis 8; gp9 – gonapophysis 9; gx8 – fused gonocoxites 8; gx9 – gonocoxite 9; T – tergite; tr – trichobothrium.
Female genitalia
(Figs
Glandular systems, as described and figured in
13 males: Holotype and paratypes.
Holotype and 1 male paratype: “PERU. CA. Hualgayoc, 6°46'14.74"S, 78°37'30.45"W, 3851 m alt., 7–14.iX.2017, L. Figueroa leg.”;
1 male paratype: “PERU. CA. Hualgayoc, 6°45'31.05"S, 78°37'19.85"W, 3997 m alt., 7–14.iX.2017, L. Figueroa leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°45'58.78"S, 78°37'33.88"W, 3968 m alt., 19.–26.Vii.2018, L. Figueroa leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°45'22.93"S, 78°37'28.45"W, 3875 m alt., 19.–26.Vii.2018, L. Figueroa leg.”; 4 males paratypes: “PERU. CA. Hualgayoc, 6°45'50.05"S, 78°39'6.20"W, 3790 m alt., 22.–27.Vii.2019, P. Sánchez leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°45'50.05"S, 78°39'6.20"W, 3790 m alt., 15.–20.iii.2019, P. Sánchez leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°45'42.15"S, 78°38’ 54.39"W, 3756 m alt., 15.–20.iii.2019, P. Sánchez leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°45'22.93"S, 78°37'28.45"W, 3875 m alt., 22.–27.Vii.2019, P. Sánchez leg.”; 1 male paratype: “PERU. CA. Hualgayoc, 6°46'55.48"S, 78°37'45.29"W, 3805 m alt., 22.–27.Vii.2019, P. Sánchez leg.”
1 female paratype: “PERU. CA. Hualgayoc, 6°45'50.05"S, 78°39'6.20"W, 3790 m alt., 7.–14.iX.2017, L. Figueroa leg.”
Holotype male, 7 paratypes (6 males, 1 female) will be deposited in coll. Museo de Historia Natural Lima, 3 male paratypes in coll. Bavarian State Collection of Zoology, Munich and 3 male paratypes in coll. Natural History Museum, Vienna.
Currently known only from the type locality in the province of Hualgayoc, Cajamarca region, Peru.
The specimens were collected in a Puna grassland (Figs
Global distribution and habitat preferences of brachypterous and, thus, flightless hemerobiids are reported in detail in
Morphological relevance of flightlessness comprises the development of wing modifications, which lead not only to flightlessness, but which also provide protection against drifting by the wind.
Within Neuroptera, completely wingless females are only known from Helicoconis aptera Messner, 1965, Coniopterygidae and both known species of the genus Adamsiana, A. curoei Penny, 1996, and A. alux Ardila-Camacho, Castillo-Argaez & Martinez, 2020, Ithonidae (
Wing modification in flightless Hemerobiidae, the phenomena of forewing reduction, forewing membrane thickening, forewing concavo-convexity and the diverse patterns of hindwing reductions are meticulously treated in
Irrespective of these theoretical considerations, it is unknown how the brachypterous specimens could have fallen into the yellow pan traps, possibly they crawled up the grass and fell into the pans (attracted by shampoo?).
Nonetheless and quasi as advocatus diaboli, we may reflect upon a common ancestry of the three brachypterous Nusalala species, namely N. brachyptera in Costa Rica, living in the ground litter at heights of 2750–3350 m, N. andina, from Colombia, living in tufts of Calamagrostis effusa at 3800 m and N. peruana sp. nov., living in a Peruvian Puna grassland at heights of 3756–3997 m. Do these three brachypterous Nusalala species have a common stem species? Are they a monophylum or has each of them its particular, but inconspicuous, “normal” sister species?
Based on the morphology of male genital sclerites,
The question, which of the many Nusalala species with normal wings known from Central and South America (
Finally, given that flightlessness in Hemerobiidae evolved several times parallel and independently, it is extremely unlikely that each of the concerned species started from scratch (with sufficient numbers of mutations in a sufficient number of specimens in the course of sufficient shifts by the wind to high mountains, the fittest then having been selected). In fact, quite another scenario comes into consideration: the reactivation of ancient available patterns from common ancestors. May these be the “elytra” of the common stem species of Coleoptera and Neuropterida or does it lead back to Hemimetabola – like Orthoptera (“tegmina”), Hemiptera (“hemelytra”) or Dermaptera?
On the one hand, there are genes that control the character identity of the two pairs of wings associated with the second and third segment of the thorax of pterygote insects. On the other hand, there are genes determining the various character states, as they are responsible for the special shapes of the wings. Experimental evidence of the complexity of the network behind these genes and deeper insights gained from the “Drosophila melanogaster scenario” have been discussed by
The material was collected in the project “Monitoreo de Biodiversidad en el área de influencia de la Unidad Minera Cerro Corona” with the permission of “El Servicio Nacional Forestal y de Fauna Silvestre” (SERFOR).The permit number was RDG Nro. 234-2017-SEROR-DGGSPFFS.
Cordial thanks to both collectors of N. peruana, Luis Figueroa and Pavel Sánchez, special thanks to Luis Figueroa for providing photographs of the type locality. We are grateful to Dr Diana Silva Dávila and Dr Mabel Alvarado Gutiérrez, Museo de Historia Natural Lima, Peru for arranging the loan. We also want to thank Dr Juliane Diller for introducing us to the museum in Lima. Many thanks to Mag Harald Bruckner, Natural History Museum Vienna, for providing photographs of the type material and to Dr John Plant for polishing the English and critically reading the manuscript.
Sincere thanks to Dušan Devetak (Maribor), Peter Duelli (Zürich), Caleb Califre Martins (presently Mexico City), Alexi Popov (Sofia) and Susanne Randolf, Subject Editor (Vienna) for thoroughly reviewing and improving the manuscript. We gratefully acknowledge the Museum für Naturkunde Berlin for waiving the author’s fees.