97 on the Occurrence of Nineta Pallida (Schneider
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Entomologist’s Rec. J. Var. 126 (2014) 97 ON THE OCCURRENCE OF NINETA PALLIDA (SCHNEIDER, 1846) AND N. INPUNCTATA (REUTER, 1894) IN THE BRITISH ISLES AND REMARKS ON THESE RARE GREEN LACEWINGS (NEU.: CHRYSOPIDAE) 1 MICHEL CANARd, 2 dAVE WILTON ANd 3 COLIN W. PLANT 1 47 chemin Flou de Rious, F-31400 Toulouse, France (e-mail: [email protected]) 2 25 Burnham Road, Westcott, Aylesbury, Buckinghamshire, HP18 0PL, UK (e-mail: [email protected]) 3 14 West Road, Bishops Stortford, Hertfordshire CM23 3QP, UK (e-mail: [email protected]) Abstract A third record of the green lacewing Nineta pallida (Schneider, 1846) is reported for Britain. A published record of Nineta inpunctata (Reuter, 1894) is shown to be an error, leaving only one valid British Isles record for that species. The opportunity is taken to discuss distribution, status and ecology of these two rare lacewings in Britain and France. Key words. Neuroptera, Chrysopidae, Nineta pallida, Nineta inpunctata, morphology, distribution, life cycle, univoltinism, photoperiod sensitivity. Nouvelles données sur la présence de Nineta pallida (Schneider, 1846) et de Nineta inpunctata (Reuter, 1894) dans les îles britanniques et remarques sur ces rares chrysopes (Neu.: Chrysopidae). Résumé Un troisième enregistrement de la chrysope verte Nineta pallida (Schneider, 1846) est signalé pour la Grande-Bretagne. Un compte rendu publié de Nineta inpunctata (Reuter, 1894) est une erreur, laissant seulement un enregistrement valide pour les îles britanniques de cette espèce. L’occasion est saisie pour discuter de la distribution, du statut et de l’écologie de ces deux chrysopes rares en Grande-Bretagne et en France. Mots clés. Neuroptera, Chrysopidae, Nineta pallida, Nineta inpunctata, morphologie, distribution, cycle de vie, univoltinisme, photopériodisme. Introduction Members of the green lacewing genus Nineta Navás, 1912 are characterized within the Chrysopini by several morphological characters, specifically a rather great size, symmetrical mandibles with small basal tooth on each, head immaculate or only marked with small red spots (at least in West Palaearctic species), abdominal sternites 8 and 9 separate and very distinctive male external genitalia with elongate ectoprocts and upturned tip of sternite 9 (Brooks & Barnard, 1990). Two species are widespread and common throughout Great Britain and, although records are sparse, appear likely to be widespread in Ireland (Plant, 1994). Both species are associated with a range of deciduous trees: N. vittata (Wesmael, 1841) and N. flava (Scopoli, 1763) (see 98 Entomologist’s Rec. J. Var. 126 (2014) Killington, 1936; Frazer, 1959; Plant, 1994, 1997). They are easy to distinguish from each other and are familiar to British entomologists. Two other Nineta species are much more rare and known from few specimens. Nineta inpunctata (Reuter, 1894) is known with certainty from only one example (see Plant, 1996); a more recent report (Plant & Shortall, 2012), is now known to be a misidentification of Nineta pallida (Schneider, 1846) which was added to the British fauna by Harvey & Plant (2007). A recent capture of a third example of N. pallida strengthens its occurrence in Britain and gives us the opportunity to clarify some elements of morphology, biological characters and European distribution. British Isles records of Nineta inpunctata and N. pallida There is a single reliable record of N. inpunctata in Britain, a female from Eastend Wood at Elsenham, North Essex, 26 June 1989, leg. & det. C. W. Plant (Plant, 1996). The identification was confirmed by the late Herbert Hölzel (Brückl, Austria). This site is approximately 200 metres from the south-eastern end of the main runway at Stansted Airport. The report of Nineta inpunctata from Suffolk given in Plant & Shortall (2012) is now known to be a misidentification of N. pallida and stems from a mistranslation of a critical couplet in the French key provided by Canard, Cloupeau & Leraut (1998). Nineta pallida was added to the British list by Harvey & Plant (2007) who reported a female captured by Martin Harvey at Wendover Woods, Buckinghamshire on 23 September 2006. A second example came to a 12.2 metres tall suction trap, operated by the Rothamsted Insect Survey at Brooms Barn, near Bury St Edmunds, West Suffolk, on 23 September 2012; this was erroneously reported as Nineta inpunctata by Plant & Shortall (2012) – a mistake that can be directly attributed to a mistranslation of the French identification key. A third British example is now reported for the first time – a single female was taken at twin-30 watt actinic light at Westcott, Buckinghamshire on 2 October 2013, leg. d. Wilton (Plate 1). Morphological discrimination of adults Males The male genitalia of Nineta species are unambiguously different and provide ready identification. drawings produced by MC, first published in Canard et al., (1998) are repeated here (Fig. 1). Females The females are much less easily distinguished and we therefore give below some characters of gross morphology that are of value in the separation of these two, based upon the detailed description of inpunctata (Tjeder, 1938) and on characters visible in our images in Plate 1 & 2. Entomologist’s Rec. J. Var. 126 (2014) 99 Plate 1. Nineta pallida (Schneider, 1846). Westcott, Buckinghamshire, 2.x.2013, leg. d. Wilton. In collection C. W. Plant. Photograph © dave Wilton Plate 2. Nineta inpunctata (Reuter, 1894). Montrigaud, drôme, France, (45° 13’ N : 05° 07’ W), 23.v.2008. Photograph © Jean-Michel Faton www.galerie-insect.org/galerie , Le Monde des Insectes. 100 Entomologist’s Rec. J. Var. 126 (2014) 1 2 3 4 Fig. 1. Lateral view (insect with head to right) of the male terminalia of British Isles Nineta species.1. N pallida ; 2. N. inpunctata ; 3. N. flava ; 4. N. vittata. All drawings © Michel Canard. Correction to a previously published key The most recent identification keys to British lacewings are those by Plant (1997). A revision of these as they affect Nineta was presented by Plant in Harvey & Plant (2007), but as a consequence of mistranslation, this introduces a confusion over the colour of the pseudo-median vein ; using these revised couplets, specimens of N. pallida will key out as N. inpunctata . A correction is therefore required. The following key couplets completely replace all earlier British keys to Nineta species; the couplet numbering follows and modifies that given by Plant (1997). 15 Antennal scape (the large basal segment of the antenna) twice as long as wide (usually obvious to the unaided eye). ... N. vittata – Antennal scape only slightly longer than wide or more or less square ... 16 16 Forewing length 16 mm or greater (but read note 1). Costal margin of forewing straight, convex or concave. ... 17 Entomologist’s Rec. J. Var. 126 (2014) 101 – Forewing length less than 16 mm (but read note 1). Costal margin of forewing straight or convex, but never concave.Not Nineta ... 18 17 Costal margin of forewing concave (Fig. 106 in original key). This character may be less obvious in females, and it is recommended that a straight edge be placed along the costa to aid interpretation .... 17a – Costal margin of forewing not concave – straight or convex ... 17b 17a Costal cross-veins of forewings more or less entirely pale, rarely darkened. Cilia in the basal fifth (nearest the body) pale and relatively long and thin, at least as long as the width of the costa and sometimes longer than this width. Hairs on the front face of the front coxae pale, long and fine ... N. flava – Costal cross-veins of forewings more or less entirely darkened ... N. guadarramensis or at least darkened at the ends. Non-British species requiring and confirmation if recorded here N. principiae 17b Pseudo-median vein of forewing black (or at least darkened compared to the cross-veins). Costal cross veins of forewings green. Upper surface of thorax with yellow/green stripe flanked on each side by reddish-brown bands (note that colours may fade, especially in alcohol) ... N. pallida – Pseudo-median and other long veins of forewings (radial sector and pseudo-cubital) green. Upper surface of thorax green and yellow – never with reddish brown markings ... 17c 17c All cross-veins black or nearly so. In the forewing, the radial sector and the distal “zig-zag” section of the pseudo-median vein (the inner gradate veins) converge towards the wing tip (Fig. 3). Cilia in the basal fifth of the costa of the forewing black, short and stout, scarcely longer than the width of the costa. Hairs on the front face of the front coxae short, stout and black ... N. inpunctata – At least the costal cross veins of forewings green – not darkened. In the forewing, the radial sector and the distal “zig-zag” section of the pseudo-median vein do not converge, but run more or less parallel to each other all the way to the wing tip. Non-British species requiring confirmation if recorded here ... N. carinthiaca Note 1 : The wing length character is designed to identify British Nineta species only, though it also works for other species currently known from Western Europe. In a wider geographical sphere, the forewings of Pseudomallada marianus (Navás, 1905) are 16 mm long, those of Ps. abdominalis (Brauer, 1856) reach 18 mm. The female of Chrysopa gibeauxi (Leraut, 1989) has a span up to 45 mm. Conversely, Nineta afghanica Hölzel, 1982 (16 mm) and N. pomacea Zakharenko, 1983 (14.5 mm) are smaller species. In all cases of doubt the taxonomic character of relevance is the symetrical nature of the two mandibles of Nineta species, which is shared only by Chrysotropia Navás, 1911. Bio-ecology of Nineta spp. Nineta pallida is strictly associated with conifers of the genus Abies (Silver Firs) and Picea (Spruce). In Hungary, it appears to be confined to Picea (Popov, 2002) and in Slovakia it is a component of the canopy fauna (Szentkirályi & Krištín, 2002).