Introduction
Green lacewings (Neuroptera: Chrysopidae) constitute one of largest families of Neuroptera (Brooks and Barnard Reference Brooks and Barnard1990). They are popularly known for their use in biological control of aphids (Hemiptera: Aphidoidea) and other small arthropod plant pests (e.g., Bigler Reference Bigler1984; Ridgway and Murphy Reference Ridgway and Murphy1984; Tulisalo Reference Tulisalo1984).
The fossil record of Chrysopidae is relatively rich, with 22 named genera and 58 named species (including that described here) assigned to three subfamilies: the extinct Limaiinae, and the extant and fossil Nothochrysinae and Chrysopinae. Limaiinae has eight described Mesozoic genera with 25 species (from the Late Jurassic to Late Cretaceous), and one Eocene genus with two named species (Table 1). Other Mesozoic Chrysopidae have not been assigned to subfamily. Fossil Nothochrysinae include 12 named genera and 23 species (including the new species) from the early Eocene to the Pliocene of Europe, Asia and North America (Table 1). Fossil Chrysopinae are assigned to eight species of one extinct genus and two extant genera, from the late Eocene and Miocene of Europe and the Caribbean region.
Table 1 A checklist of named fossil species of Chrysopidae
1, Panfilov (Reference Panfilov1980); 2, Rasnitsyn and Zherikhin (Reference Rasnitsyn and Zherikhin2002); 3, Martynov (Reference Martynov1927); 4, Nel et al. (Reference Nel, Delclòs and Hutin2005); 5, Jepson et al. (Reference Jepson, Makarkin and Coram2012); 6, Makarkin (Reference Makarkin1997); 7, Makarkin et al. (Reference Makarkin, Yang, Peng and Ren2012); 8, Ren and Guo (Reference Ren and Guo1996); 9, Yang and Hong (Reference Yang and Hong1990); 10, Ponomarenko (Reference Ponomarenko1992); 11, Martins-Neto and Vulcano (1989); 12, Martill and Heimhofer (Reference Martill and Heimhofer2008); 13, Martins-Neto (Reference Martins-Neto2003); 14, Martins-Neto (Reference Martins-Neto1997); 15, Makarkin (Reference Makarkin1994); 16, Willmann and Brooks (Reference Willmann and Brooks1991); 17, Chambers et al. (Reference Chambers, Pringle, Fitton, Larsen, Pedersen and Parrish2003), and see discussion by Archibald et al. (Reference Archibald, Cover and Moreau2006); 18, Schlüter (Reference Schlüter1982); 19, Willmann (Reference Willmann1993); 20, Makarkin and Archibald (Reference Makarkin and Archibald2013); 21, Archibald et al. (Reference Archibald, Bossert, Greenwood and Farrell2010); 22, Wolfe et al. (Reference Wolfe, Gregory-Wodzicki, Molnar and Mustoe2003); 23, Moss et al. (Reference Moss, Greenwood and Archibald2005); 24, Makarkin (Reference Makarkin2014); 25, Cockerell (Reference Adams1914); 26, Evanoff et al. (Reference Evanoff, McIntosh and Murphey2001); 27, Adams (Reference Cockerell1967); 28, Scudder (Reference Scudder1890); 29, Cockerell (Reference Cockerell1909); 30, Scudder (Reference Scudder1885); 31, Séméria and Nel (Reference Séméria and Nel1990); 32, Nel and Séméria (Reference Nel and Séméria1986); 33, Carpenter (Reference Carpenter1935); 34, Lanphere (Reference Lanphere2000); 35, Statz (Reference Statz1936); 36, Peñalver et al. (Reference Peñalver, Nel and Martínex-Delclòs1995); 37, Barron et al. (Reference Barron, Rivas-Carballo, Postigo-Mijarra, Alcalde-Olivares, Vieira and Castro2010); 38, Engel and Grimaldi (Reference Engel and Grimaldi2007); 39, Iturralde-Vinent and MacPhee (Reference Iturralde-Vinent and MacPhee1996); 40, Makarkin (Reference Makarkin1991); 41, Goncharova (Reference Goncharova1989); 42, Handschin (Reference Handschin1937); 43, Sziráki and Dulai (Reference Sziráki and Dulai2002); 44, Thil et al. (Reference Thil, Klotz and Uhl2012). CHRN, Chrysopinae; LIMN, Limaiinae; NOTN, Nothochrysinae; mya, million years ago.
Chrysopinae is the dominant subfamily today with over 1200 species, which are distributed globally; and Nothochrysinae is a small, relict, sporadically distributed subfamily, with 21–22 species (Yang Reference Yang1986; Brooks and Barnard Reference Brooks and Barnard1990; Adams and Penny Reference Adams and Penny1992a; Kovanci and Canbulat Reference Kovanci and Canbulat2007). A third, small extant mainly tropical subfamily, Apochrysinae, has no known fossil record (Winterton and Brooks Reference Winterton and Brooks2002).
Here, we describe a new species of Nothochrysinae from Driftwood Canyon, British Columbia, Canada, which we assign to the genus Archaeochrysa Adams. This genus is the most species rich among fossil nothochrysines, with its five species known from the early Eocene of British Columbia, Canada, the late Eocene of Florissant, Colorado, United States of America, and the early Oligocene of Creede, Colorado.
Materials and methods
Locality and material
We base this species on a single fossil forewing preserved in lacustrine shale from the Okanagan Highlands locality at Driftwood Canyon Provincial Park, near the town of Smithers in northwestern British Columbia, Canada. It was collected under BC Parks park use permit SK08116495.
Driftwood Canyon is the northernmost known occurrence of the series, which were deposited in early Eocene lake basins scattered over roughly 1000 km southeast to Republic in north-central Washington, United States of America (Archibald et al. Reference Archibald, Greenwood, Smith, Mathewes and Basinger2011). This fossil, like many from Driftwood Canyon, was recovered from very fine-grained shale, and, unlike fossils from other Okanagan Highlands localities, was preserved only on one side of the split rock, without a counterpart. Fossil insects there are commonly found in layers that are at times very dense with insect fossils. This piece of shale, roughly 65×20 cm also bears wings of Ichneumonidae (Hymenoptera), Tipulidae (Diptera), various Sciaroidea (Diptera) wings and bodies, as well as other insect body parts (RBCM numbers RBCM.EH2014.033.0001.002 to RBCM.EH2014.033.0001.009). Driftwood Canyon insects often show a notably fine degree of perseveration (e.g., see Archibald et al. Reference Archibald, Greenwood, Smith, Mathewes and Basinger2011, fig. 6).
A preliminary age for Driftwood Canyon sediments of 51.77±0.34 million years ago (mya) is indicated by U–Pb analysis of zircons recovered from a tephra layer intercalated within the fossil-bearing shale (Mortensen and Archibald work in progress cited by Moss et al. Reference Moss, Greenwood and Archibald2005).
Okanagan Highlands sites preserved cooler (mostly upper microthermal) montane forests during the warmest sustained interval of the Cenozoic; various floristic proxy analyses indicate that Driftwood Canyon was the coolest of the series (Greenwood et al. Reference Greenwood, Archibald, Mathewes and Moss2005). The climate and flora have been characterised by Greenwood et al. (Reference Greenwood, Archibald, Mathewes and Moss2005) and Moss et al. (Reference Moss, Greenwood and Archibald2005). The insect fauna has been extensively collected in recent years by S.B.A. (with Greenwood and associates). Neuroptera are represented at this locality by the families Chrysopidae and Osmylidae. Chrysopids were recently the first named species from this site (Makarkin and Archibald Reference Makarkin and Archibald2013). Osmylidae and Raphidioptera are known by one undescribed species each (S.B.A. and V.N.M., personal observation).
Terminology
We use the venational terminology of Kukalová-Peck and Lawrence (Reference Kukalová-Peck and Lawrence2004) as modified by Yang et al. (Reference Yang, Makarkin, Winterton, Khramov and Ren2012), except for anal veins, which in general follows that applied to other Neoptera by, for example, Béthoux (Reference Béthoux2005) and Béthoux and Jarzembowski (Reference Béthoux and Jarzembowski2010) wherein all anal veins are considered as branches of the anterior analis. Crossveins are designated after the longitudinal veins with which are they connected and are numbered in sequence from the wing base, e.g., 1scp-r, first (proximal-most) crossvein connecting ScP and R/RA; icu, crossvein between CuA and CuP. Terminology of wing spaces and details of venation (e.g., veinlets) follows Oswald (Reference Oswald1993).
Abbreviations: AA1–AA3, first to third branches of anterior anal vein; CuA, anterior cubitus; CuP, posterior cubitus; im, intramedian cell; MA and MP, anterior and posterior branches of media; Psc, pseudocubitus; Psm, pseudomedia; RA, anterior radius; RP, posterior radius; RP1, proximal-most branches of RP; ScP, subcosta posterior.
Genus Archaeochrysa Adams (Chrysopidae: Nothochrysinae)
Archaeochrysa sanikwa Archibald and Makarkin, new species
Fig. 1 Archaeochrysa species. (A) A. sanikwa new species from Driftwood Canyon, holotype RBCM.EH2014.033.0001.001, photograph; (B) same, drawing (both converted to standard view, with apex to the right); (C) A. profracta Makarkin and Archibald (Reference Makarkin and Archibald2013) from McAbee, holotype UCCIPR L-18F-1527, re-drawn from Makarkin and Archibald (Reference Makarkin and Archibald2013) with new labelling and addition of 1scp-r. Crossveins of the pseudocubitus (Psc) and proximal part of outer gradate series (proximad RP5) are shown in red and further indicated by red arrows. The asterix (*) indicates 1scp-r, the crossvein connecting ScP and RA. Scale=2 mm (all to scale).
Diagnosis
Forewing may be distinguished from that of other species of the genus by a combination of the following character states: 2 m-cu located slightly distad middle of intramedian cell (slightly proximad middle of intramedian cell in A. profracta Makarkin and Archibald; distinctly proximad in A. fracta Adams, A. paranervis Adams, A. creedei (Carpenter)); sides (MA and MP) of intramedian cell converging basally at low angle (sides of intramedian cell parallel and converging basally at steeper angle in A. paranervis, A. creedei); distance from origin of RP to crossvein 1r-m markedly shorter than length of intramedian cell (nearly equal in A. profracta, A. paranervis, A. creedei); only one crossvein of Psc lost, others confidently identified (most crossveins lost or indefinable in A. profracta); basal crossvein 1scp-r located between origin of RP, proximal-most crossvein between RA, RP (between two proximal crossveins between RA, RP in A. profracta).
Etymology
The specific epithet sanikwa was suggested to us by Elders of the Wet’suwet’en Nation of northwest British Columbia, whose traditional territory includes Driftwood Canyon Provincial Park. It is formed from the word sanikwa (or spelled Sani kwa) in the Wet’suwet’en language, which refers to the transformation of insects, specifically metamorphosis as seen in butterflies, but here referring to the appearance of this ancient insect in our time. It also makes reference here to the Wet’suwet’en connection to the environment.
Material
Holotype: RBCM.EH2014.033.0001.001 (original collection number: SBA 4922), part only. An almost complete forewing, mostly well preserved but slightly crumpled and torn. Housed in the collection of the Royal British Columbia Museum, Victoria, British Columbia, Canada. Collected by S.B.A. at Driftwood Canyon on 13 July 2008.
Description
Forewing 10.5 mm long; 3.8 mm wide as preserved (estimated complete width 3.9 mm). Costal space moderately wide, most dilated at level of proximal-most ra-rp crossvein. Humeral veinlet not distinctly visible. Subcostal veinlets simple, 16 in number (proximad pterostigmal region), rather closely spaced. Pterostigma rather distinct, only slightly darker than other membrane as preserved; presence of incorporated veinlets, crossveins unclear. ScP long, entering wing margin rather far from apex. Subcostal space narrow; basal crossvein 1scp-r located between origin of RP, proximal-most crossvein between RA, RP. RA entering margin at wing apex, strongly zigzagged apically, with 10 short distal veinlets. RA space broad, with 19 crossveins (distal ones not completely preserved). Stem of RP slightly zigzagged, with 11 branches (or 12; distal-most branch possibly not preserved); all preserved branches deeply forked except distal-most; three branches with additional shallower fork of one of branch each. Basal crossvein 1r-m very short, connecting stem of RP, stem of M at its fork. M dividing into MA, MP far distad origin of RP. MA strongly arched, deeply forked at Psc; MP zigzagged, deeply forked at Psc; MA, MP weakly divergent towards Psc. Between MA, MP one crossvein before Psc. Intramedian cell rather long, narrow, tapering basally. Psm weakly developed, strongly zigzagged. Crossvein 2m-cu (between intramedian cell, CuA) shifted distally, placed in distal portion of intramedian cell. CuA with three simple branches. CuA continuing into well-developed Psc, which continues into outer gradate series of crossveins. Basal part of CuP; other posterior portions of forewing (rest of CuP, 1icu, 2icu, anal veins) not preserved. Two gradate series of crossveins parallel; inner series with 11 crossveins distal to MA; outer series incompletely preserved.
Locality and age
Driftwood Canyon Provincial Park (public face exposure), near Smithers, British Columbia; mid-Ypresian, 51.77±0.34 mya.
Remarks
The two species Archaeochrysa sanikwa and A. profracta from Okanagan Highlands are certainly closely related (see Figs. 1B, 1C); both are from the interior of British Columbia, Driftwood Canyon and McAbee and both are from the mid-Ypresian, with a million years or so separating them (see Table 1). Their venation differs only in small details. However, Archaeochrysa sanikwa is hypothesised to be more primitive than the McAbee species (see below).
Discussion
Some character states found in the new species are of phylogenetic interest.
(1) The shape of the intramedian cell. Species of Archaeochrysa may be divided into two groups based on the shape of the intramedian cell (im).
Condition 1: im is narrow, quite long, tapering, that is, its sides (MA and MP) converging basally at a low angle (Figs. 1B, 1C; and see Makarkin and Archibald Reference Makarkin and Archibald2013, fig. 15). This includes the early Eocene A. profracta and A. sanikwa from the Okanagan Highlands, and A. fracta from the late Eocene of Florissant. This condition is very likely plesiomorphic for the subfamily, as a similar configuration is found in the vast majority of Mesozoic chrysopid species (including all Limaiinae; Fig. 2A), and MA and MP also diverge at acute angle in other families of Neuroptera with generalised venation. The shape of im varies in other nothochrysines, but never appears in such a plesiomorphic condition as this.
Fig. 2 Evolution of the position of the crossvein 2m-cu in Chrysopidae. (A) Mesypochrysa magna Makarkin from the Early Cretaceous, re-drawn from Makarkin (Reference Makarkin1997); (B) Asiachrysa tadushiella Makarkin from the early/middle Eocene, re-drawn from Makarkin (Reference Makarkin2014); (C) Palaeochrysa stricta Scudder from the late Eocene, re-drawn from Adams (Reference Adams1967); (D) the extant Kimochrysa africana (Kimmins), re-drawn from Tjeder (Reference Tjeder1966). Drawings are slightly schematic. To various scales.
Condition 2: im differs by its sides (MA and MP) being more parallel (Fig. 2C), and MP basad 2m-cu converge at a steeper angle (i.e., im remains wider basally: see Adams Reference Adams1967, figs. 40, 41). This includes A. paranervis from Florissant and A. creedei from Oligocene of Creede. A similarly shaped im is found in all other fossil Nothochrysinae from the late Eocene Florissant and early Oligocene Creede deposits (i.e., Palaeochrysa Scudder, Tribochrysa Scudder, Dispetochrysa Adams), and is also seen in many extant species (of Nothochrysa McLachlan, most Pimachrysa Adams, some Kimochrysa Tjeder) (Adams Reference Adams1967, figs. 1–3; Tjeder Reference Tjeder1966, fig. 839; Brooks and Barnard Reference Brooks and Barnard1990, figs. 545, 561).
(2) The position of the crossvein 2m-cu. The position of this crossvein is especially illustrative of evolutionary trends in chrysopid wing venation (see Makarkin and Archibald Reference Makarkin and Archibald2013). Several conditions may be identified for the location of crossvein 2m-cu in the family.
Condition 1: located in the distal part of an elongated im (Fig. 2A); this condition is most likely plesiomorphic in the family. This occurs in the vast majority of Mesozoic Chrysopidae, and in the limaiine genus Protochrysa that is found in the early Eocene of Denmark and the Okanagan Highlands (Willmann and Brooks Reference Willmann and Brooks1991; Makarkin and Archibald Reference Makarkin and Archibald2013). The only other occurrence of this condition is in the enigmatic extant monotypic genus Leptochrysa Adams and Penny from South America, which has 2m-cu positioned distally (Adams and Penny Reference Adams and Penny1992b, fig. 10); however, this genus might belong to the Limaiinae (Makarkin and Archibald Reference Makarkin and Archibald2013).
Condition 2: located slightly distad mid-point of im; this condition is found in the new species and is most likely plesiomorphic in Nothochrysinae (Fig. 1B).
Condition 3: located nearly at middle of im (Fig. 2B); this occurs in the early Eocene Cimbrochrysa Schlüter and Stephenbrooksia Willmann, and the early/middle Eocene Asiachrysa Makarkin.
Condition 4: located slightly proximad mid-point of im; this occurs in the early Eocene Danochrysa Willmann, Okanaganochrysa Makarkin and Archibald, some Adamsochrysa Makarkin and Archibald, and Archaeochrysa profracta (Fig. 1C).
Condition 5: located distinctly in the proximal part of im (Fig. 2C); this occurs in the majority of Nothochrysinae genera: some early Eocene species (of Pseudochrysa Makarkin and Archibald; and Adamsochrysa wilsoni Makarkin and Archibald), and all fossil species from the late Eocene onward (except the Pliocene Hypochrysa Hagen) and some extant (those of Nothochrysa, most Pimachrysa, and some Kimochrysa: Adams Reference Adams1967, figs. 1–4; Tjeder Reference Tjeder1966, figs. 785, 839; New Reference New1980, figs. 42, 44; Brooks and Barnard Reference Brooks and Barnard1990, figs. 527, 545, 561).
Condition 6: located proximad im (Fig. 2D); this occurs in the Pliocene to Recent genus Hypochrysa and in the majority of extant genera: Triplochrysa Kimmins, Pamochrysa Tjeder, Asthenochrysa Adams, most Dictyochrysa Esben-Petersen, some Pimachrysa and Kimochrysa (Adams Reference Adams1957, fig. 1; 1967, fig. 5; Tjeder Reference Tjeder1966, figs. 822, 835; Brooks and Barnard Reference Brooks and Barnard1990, figs. 533, 539, 554, 567).
The evolutionary trend of the location of 2m-cu in Chrysopidae is clear, shifting from a distinctly distal position in the Mesozoic Limaiinae to a very proximal one in most extant Nothochrysinae. Archaeochrysa sanikwa occupies an important place in this chain, as the only representative of the Nothochrysinae bearing the plesiomorphic condition for the subfamily (condition 2).
(3) The crossveins of Psc. The pseudocubitus is formed by the alignment of sections of branches of MA, MP, and Rs, and the crossveins connecting them. The formation of the Psc is a clearly apomorphic condition of Chrysopidae. The Psc continues CuA; its crossveins are part of an outer gradate series, running from CuP to the anterior trace of RP (at most). The configuration of the Psc in Nothochrysinae may also be categorised in distinct conditions.
Condition 1: all crossveins of Psc are present and may be confidently identified. This is most likely primitive in the subfamily (and family) and is found in the Eocene Asiachrysa, Pseudochrysa, and Tribochrysa.
Condition 2: only one crossvein is lost, usually between MA and RP1 (these are touching at Psc), other crossveins are present and identified; it is seen in Archaeochrysa sanikwa (Fig. 1B), A. creedei, and A. fracta.
Condition 3: most crossveins of the proximal Psc are lost or not identifiable; this is found in most fossil Nothochrysinae (e.g., Cimbrochrysa, Stephenbrooksia, Danochrysa, Okanaganochrysa, Adamsochrysa, Archaeochrysa profracta (Fig. 1C)), and in some extant (e.g., Dictyochrysa).
Condition 4: Psc is long and straight (or so) with no crossveins identifiable as such with certainty, a most derived condition seen in few Nothochrysinae (late Oligocene to Recent): some Nothochrysa and Pronothochrysa Peñalver, Nel, and Martínez-Delclòs.
This phylogenetic trend in the development of Psc is also distinct when compared among chrysopid subfamilies. Psc is poorly developed in the predominantly Mesozoic Limaiinae: most of its species show condition 1, only some have condition 2 (e.g., some species of Mesypochrysa Martynov from the Early Cretaceous locality of Baissa in Transbaikalia; Makarkin Reference Makarkin1997, figs. 1, 4, 13), and conditions 3 and 4 are never known. In all Chrysopinae (which dominate the family today) Psc is very well developed; their species exhibit only conditions 3 and 4, and never have the more plesiomorphic conditions. In the subfamily Apochrysinae (unknown in the fossil record), only condition 4 occurs (see Brooks and Barnard Reference Brooks and Barnard1990).
Therefore, the forewing venation of this species is very plesiomorphic compared with the vast majority species of Nothochrysinae, both fossil and extant.
Archaeochrysa sanikwa is the smallest species of the genus. In general, most chrysopids from the Driftwood Canyon locality are small; in fact, Pseudochrysopa harveyi Makarkin and Archibald is the smallest known fossil member of the family, with forewings only 7.2 mm long as preserved, probably about 8.5 mm long in life (Makarkin and Archibald Reference Makarkin and Archibald2013).
Acknowledgements
The authors thank the Elders of the Wet’suwet’en Nation for providing us with the word sanikwa with which to form the specific epithet, and Mike Ridsdale of the Office of the Wet’suwet’en for connecting us with the Elders and communicating their wishes to us (missiyh: thank you); BC Parks, and in particular John Howard (Babine Area Supervisor, BC Parks) for permitting and facilitating work at Driftwood Canyon; the above and other people of the Smithers, British Columbia region for their warm welcome at Driftwood Canyon Provincial Park. We thank Richard Hebda (curator) and Marji Johns (collections manager) at the Royal British Columbia Museum for facilitating this specimen’s study, and Marlow Pellatt of Parks Canada of access to microphotography equipment. Funding for S.B.A. has been generously provided by Rolf Mathewes (Simon Fraser University) for laboratory space and general funding, and David Greenwood (Brandon University, Brandon, Manitoba, Canada) who also provided Driftwood Canyon fieldwork support. The study is partly supported by a President’s Grant for Government Support of the Leading Scientific Schools of the Russian Federation No.HIII-150.2014.4, and the grant of the Far Eastern Branch of the Russian Academy of Sciences No. 12-I-II30-03 for V.M.
