Austroperla cyrene Newman (Plecoptera: Austroperlidae)

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1 Journal of The Royal Society of New Zealand, Volume 27, Number 2, June 1997, pp Austroperla cyrene Newman (Plecoptera: Austroperlidae) I. D. McLellan* Amended diagnoses of Austroperla and the family Austroperlidae are given. A revised description is given of Austroperla cyrene (Plecoptera : Austroperlidae), type species of the monotypic genus Austroperla and the sole austroperlid in New Zealand. Included are notes on its distribution and biology. Keywords: taxonomy; revision; biology; Plecoptera; Austroperlidae; Austroperla cyrene INTRODUCTION Austroperla cyrene (Newman, 1845), the black stonefly and the eustheniid Stenoperla prasina (Newman, 1845), the large green stonefly were the first stonefly species described from New Zealand, and no others were described for another 64 years. Both are distinctive species and well known to anglers and others who frequent New Zealand streams and rivers, hence their common names. Professor E. Percival of Canterbury University College suggested that Thomson (1934) and Helson (1934) study the two species, and so they have the triple distinction of being the first New Zealand stoneflies to be described, the first to have common names, and the first to have their biology investigated. Austroperla cyrene is the only austroperlid in New Zealand and the sole species in Austroperla, the type genus of the family Austroperlidae, which was raised by Tillyard (1921) to contain Austroperla and Tasmanoperla. He gave no formal diagnosis for the family, but the characters he used for division of families in Perlaria (= Plecoptera) are contained in a table and a set of keys, both of which are based on mouthparts, wing venation, legs, and gills. Tillyard (1923) gave a brief diagnosis ofaustroperla based on wing characters. Tillyard (1923) figured the wing venation of Austroperla cyrene and gave a brief description. Kimmins (1938) gave a more detailed description and figured wings and male and female genitalia. Winterboura (1965) gave the first detailed description of the nymph and figured the gills. lilies (1969) gave diagnoses of Austroperlidae and Austroperla, and illustrated and described the nymph and adult coloration of A. cyrene. Although he figured the wings and male and female genitalia he referred the reader to Kimmins (1938) for descriptions. After comparing specimens of Austroperla cyrene with the figures and description of male genitalia in Kimmins (1938), I see that there are some mistakes and omissions. For instance, he recognised and drew the basal sclerite of the epiproct, referring to it as a wide shelf-like base, but he did not show its division, which is an important generic character. He also refers to the triangular tip of the epiproct incorrectly as "a large conical tubercle" on the basal sclerite, and omitted in the description reference to the epiproct basal process, although he drew it. Since Kimmins's (1938) description and Illies's (1969) diagnoses our knowledge of the structure of male genitalia in Antarctoperlaria has made some advances. McLellan (1971, 1993) evolved terms for describing male gripopterygid genitalia, but unfortunately Hynes (1974, 1976) used some of these terms to describe seven austroperlids without realising that Private Box 95, Westport, New Zealand

2 272 Journal of The Royal Society of New Zealand, Volume 27, 1997 the parts he named were not homologous with those in Gripopterygidae. Here are more suitable terms, which should be used only for austroperlids, contrasted with those used by Hynes (1974) [in brackets]: tergite 10 [anterior sclerites of tergite 10]; epiproct basal sclerite [central sclerite of tergite 10]; epiproct basal process [posterior sclerite of tergite 10]. In most austroperlid genera tergite 10 is divided medially into the two sclerites. The epiproct basal sclerite is situated across the posterodorsal surface of segment 10, and is attached to lateral supporting sclerites of the epiproct. In the membranous triangular area bounded by these sclerites arises the peg-like epiproct basal process. Zwick (1981) had also noticed the origin of this basal process when he commented on Illies's (1969) incorrect use of terminal filament (the median gill filament in nymphs) for the posterior process (epiproct basal process). The membranous penis of gripopterygid males and its use in producing a spermatophore was first recorded by McLellan (1971), who later (1993) described the spermatophore, penis structure, and copulation in Zelandobius (Antarctoperlinae). Zwick (1979) recorded a spermatophore in Stenoperla (Eustheniidae), and McLellan (1996) described the penis of Stenoperla and Cosmioperla (Eustheniidae). Here the penis and spermatophore of Austroperla cyrene are described. Full collection data may be obtained from the author or from the Curator, New Zealand Arthropod Collection (NZAC), Manaaki Whenua Landcare Research, Mt Albert Research Centre, Private Bag , Auckland [ crosbyt@landcare.cri.nz]. The abbreviations for entomological collections of Watt (1979) are used, as are the area codes of Crosby et al. (1976) in collection data. FAMILY AUSTROPERLIDAE Type genus Austroperla Needham, Adults. Medium-sized (wing span mm), with body dark, strongly sclerotised. Wings dark with anterior margins white, yellow, red, or red-brown, or wings mottled, with regular, strong cross venation in costal field. Hind wing with 2A always forked; a sloping crossvein often running from 3A to posterior branch of 2A. Tibiae with 2 apical spurs. Male genitalia with tergite 10 divided medially; epiproct with a dorsal basal sclerite which may be divided medially; peg-like epiproct basal process situated medially in epiproct base between basal sclerite and lateral supporting sclerites; penis membranous, lobed, and constructed to mould a dart-like spermatophore. Female subgenital plate posteriorly bilobed. Nymphs. Ocelli present or absent. Cerci very short. Antennae short. Pronotum quadrangular, often with angles acutely extended. Gills tube-like or as beaded filaments, numbering either 1 or 3 in the membrane between posterior margin of tergite 10 and anus, and another on tip of each subanal lobe. Cerci often modified apically into a membranous beaded gill. There are eight genera in the family: Acruroperla, Austroheptura, Austropentura, Crypturoperla, and Tasmanoperla in Australia; Klapopteryx and Penturoperla in South America; and the monotypic type genus Austroperla in New Zealand. Genus Austroperla Needham Austroperla Needham, 1905: 109. Tillyard 1921: 40 (inclusion in Austroperlidae, additions to diagnosis); 1923:201 (additions to diagnosis). lilies 1969:40 (additions to diagnosis). Type species Chloroperla cyrene Newman (1845), by monotypy. Heteroperla Hare, 1910: 30. Tillyard 1923: 201. Adults. Medium-sized stoneflies (11 16 mm) with body heavily sclerotised, black; wings black with pale crossveins. Antennae about two-thirds of body length; cerci with 15 or 16 segments. Forewing with anal veins unforked, and between them behind 2nd crossvein a dark, raised zone (fusion of several crossveins?). Hindwing vein 2A with anterior branch forked but hind branch unforked, with no crossvein between 2A and 3A. Genitalia: male (Fig. 2 5) with epiproct basal sclerite divided medially, its inner margins

3 McLellan Austroperla cyrene 273 Fig. 1 Habitus, dorsal, nymph of Austroperla cyrene. rounded, basal process short, and epiproct tip bulged; paraprocts untapered; penis membranous, 5-lobed. Female subgenital plate (Fig. 6) slightly bilobed. Nymph (Fig. 1, 8). Body rounded, with integument dark and heavily sclerotised. Ocelli present. Antennae strongly tapered. Gills tube-like, indistinctly segmented, one at tip of each

4 274 Journal of The Royal Society of New Zealand, Volume 27, 1997 Fig. 2 5 Austroperla cyrene, male genitalia: (2) lateral; (3) dorsal; (4) posterior; (5) penis. Fig. 6 Female genitalia, ventral. Fig. 7 Spermatophore. Fig. 8 Nymph, tip of abdomen, ventral. Abbreviations: e, epiproct; p, epiproct basal process; bs, epiproct basal sclerite; lpl, lateral penial lobe; pa, paraproct; sal, subanal lobe; sgp, subgenital plate; tlo, tergite 10. subanal lobe and another above anus. Cerci short, well tapered, with last 3 or 4 segments membranous. Austroperla cyrene Needham Chloroperla cyrene Newman, 1845: 853. Austroperla cyrene Needham, 1905: 109. Heteroperla cyrene Hare, 1910: 30. Austroperla cyrene: Tillyard 1923: (description of adult; figure of wings). Kimmins 1938: (redescription, including description of male and female genitalia with figures of genitalia and wings). Winterbourn, 1965: (description of nymph and figure of gills). lilies 1969: (redescription of male, female and nymph with figures). Dimensions (mm). Male: body length 11-14; antenna ; forewing Female: body length 13-20: antenna 8-12; forewing Nymph: body length : antenna 7 9; cerci 3. Adult. Head and antennae black; nota very dark brown: legs dark brown to black, with tibiae yellow over medial third; abdomen brown. Forewings dark brown to black, with a distinct pale basal patch extending through costal cell to cubitus; from this patch a pale line following posterior margin of cubitus to hind margin of wing; another pale line extending from base of

5 McLellan Austroperla cyrene 275 media along its anterior margin to Rs+Ml crossvein. Between crossveins in costal cell are other pale patches, and an occasional pale spot in pterostigma. Veins and crossveins dark brown apart from distal crossveins posterior to radius. Hindwing similar to forewing but with no pale basal patch; pale line present at posterior of cubitus, and pterostigma with more extensive pale areas. Male genitalia (Fig. 2 5): see generic description. Female genitalia (Fig. 6): see generic description. Spermatophore (Fig. 7) a long, irregular, sagittate blade. Nymph (Fig. 1). See generic description. Type data. Holotype: male, New Zealand, Saunders, 68-3 (BMNH). Material examined. The holotype and 659 non-type specimens (125 males, 158 females, 362 nymphs, and 14 exuviae) from ND AK TO TK GB Rl WA WN/SDNNKAMB NC MC SC BR WD FD OL CO DN SL / SI. A full list of material and collection data may be obtained from the author. Remarks. There are no appreciable differences in the morphology of examples from north to south. Some wing shortening, with the wings usually terminating about abdominal segment 7 9, occurs in populations in most alpine regions, and in some lowland areas (Arnold River, BR). The pronotum has some variability in the degree of acuteness and extension of the angles; e.g., Dolamore Park (SL) specimens have anterior angles slightly produced and posterior angles rounded, whereas specimens from Mt Ruapehu (TO) have more produced and acute anterior and posterior angles. In nymphs the gills are tubular and may have irregular beading in the distal half (Dolamore Park, SL) or may be completely without beading (Waipoua, ND). Distribution (Fig. 9). Austroperla cyrene is widespread through the three main islands of New Zealand from near sea level to over 1600 m (OL, Mt Maungatika). It is also recorded from immediate offshore islands such as Secretary Island and Little Barrier, though not from the Kermadecs nor the Chatham Islands, which have no stoneflies. It is not recorded among the species found on The Snares, Auckland Islands, and Campbell Island. Biology. Thomson (1934) gave a detailed account of the anatomy of this stonefly, and was the first to describe and illustrate the nymph, its gills, and the male and female internal genitalia. She found that reared nymphs ate dead wood but preferred any bark covering it. They also ate dead animal matter, i.e., mayfly nymphs, Austroperla nymphs, and blowfly maggots. McLellan (in press) in May 1964 collected and reared nymphs in leaf packs from the Lower Buller Gorge (BR/NN). These animals utilised decaying leaves from the packs as food, and ate the soft tissue plus any fungal hyphae in it, discarding the skeletons. The most preferred leaves were of Coprosma australis. Most of the 30 nymphs reared survived to emerge as adults between October and December Collier (1990) found in the guts of A. cyrene large quantities of sooty mould fungi, which grow on the leaves of trees such as kamahi (Weimannia racemosa). These fungi, according to Barlocher (1985), have a greater nutritional value than the leaf tissue itself. Winterbourn & Rounick (1985) consider that A. cyrene, although nominally a shredder, appears to be a collector browser in some streams, feeding on fine particles of organic material and stone surface organic layers, or even grazing algae. The above observations show that this insect apparently adapts well to the differing resources of dissimilar waterways, perhaps the reason why this single species has successfully colonised all types of freshwater habitats from near sea level to alpine streams throughout the three main islands of New Zealand. Thomson (1934) found that the tissue of adults and nymphs contained hydrogen cyanide and that possibly owing to its presence nymphs were not attacked by the predatory nymphs of

6 276 Journal of The Royal Society of New Zealand, Volume 27, 1997 Fig. 9 Map showing locality records for Austroperla cyrene. the stonefly Stenoperla prasina nor, presumably, by other carnivores, and were not eaten when freshly killed. On the unpalatability of A. cyrene, McLellan (in press) found that the guts of 84 brown trout {Salmo trutta) from West Coast rivers where A. cyrene is common contained 6860 food items, 99% of which were aquatic insects. Of the 423 plecopterans present, only 2 were

7 McLellan Austroperla cyrene i \ug Sept Oct Nov Dec Jan Feb Mar April May June Juy Series 1 H Series 2 Fig. 10 Emergence of Austroperla cyrene adults in North (series 1) and South (series 2) islands. nymphs of A. cyrene. He also states that although most stoneflies have cryptic colour patterns, adults of A. cyrene have a black, white, and yellow pattern which stands out, as do the aposematic patterns displayed by other distasteful or dangerous insects. There are two undescribed New Zealand gripopterygids which have very similar colour patterns. In the large amount of collection data an extremely good picture of adult emergence appears (Fig. 10). The main emergence starts in November, peaks in December and continues through to March/April, with few adults appearing in the autumn, winter and early spring. This indicates that differences in latitude apparently have little effect on the timing of emergence. ACKNOWLEDGMENTS For material either on loan or donated I am grateful to T. K. Crosby (NZAC), R. M. Emberson (LCNZ), G. W. Gibbs (Victoria University, Wellington), J. Hape and C. M. F. Herd (Dannevirke), A. C. Harris (OMNZ), T. R. Hitchings and J. B. Ward (CMNZ), P. M. Johns (University of Canterbury, Christchurch), and B. H. Patrick (Department of Conservation, Dunedin). My sincere thanks for locality records go to I. K. G. Boothroyd (Hawkes Bay Regional Council, Napier), K. J. Collier, M. Scarsbrook, B. S. Smith, J. M. Quinn (NIWA, Hamilton), and I. M. Henderson (Massey University, Palmerston North) who also contributed material and produced the distribution map. REFERENCES Barlocher, F., 1985: The role of fungi in the nutrition of stream invertebrates. Botanical journal of the Linnean Society 91: Collier, K. J. 1990: Ingestion of sooty mould fungi by some New Zealand stream insects. New Zealand entomologist 13: Crosby, T. K..; Dugdale, J. S.; Watt, J. C. 1976: Recording specimen localities in New Zealand: an arbitary system of areas and codes defined. New Zealand journal of zoology 3: 69 + map. Hare, E. J. 1910: Some additions to the Perlidae of New Zealand. Transactions of the New Zealand Institute 42: Helson, G. A. 1934: The bionomics and anatomy of Stenoperla prasina (Newman). Transactions of the New Zealand Institute 64: , pi Hynes, H. B. N. 1974: Comments on the Taxonomy of Australian Austroperlidae and Gripopterygidae (Plecoptera). Australian journal of zoology, supplementary series no. 29. Hynes, H. B. N. 1976: Tasmanian Antarctoperlaria (Plecoptera) Australian journal of zoology 24: lilies, J. 1969: Revision der Plecopterenfamilie Austroperlidae. Entomologisk Tidskrift 90:

8 278 Journal of The Royal Society of New Zealand, Volume 27, 1997 Kimmins, D. E., 1938: Notes on the Plecoptera of New Zealand, with descriptions of new species. The annals and magazine of natural history 11(2): McLellan, I. D. 1971: A revision of Australian Gripopterygidae (Insecta : Plecoptera). Australian journal of zoology, supplement no.2. McLellan I. D. 1993: Antarctoperlinae (Insecta: Plecoptera). Fauna of New Zealand 27. McLellan, I. D. (in press): Austroperla cyrene, an adaptable and unpalatable New Zealand stonefly. Proceedings of the 8th International Conference on Ephemeroptera and the 12th International Symposium on Plecoptera, Lausanne, Needham, J. G. 1905: New genera and new species of Perlidae. Proceedings of the Entomological Society Washington 18: Newman, E. 1845: Addendum to the 'Synonymy of the Perlites', published in The annals and magazine of natural history for Zoologist 3: Thomson, Margaret S. 1934: An account of the systematics, anatomy and bionomics of Austroperla cyrene Newman. Unpublished MSc (Hons) thesis, Canterbury University College, Christchurch, New Zealand. Tillyard, R. J. 1921a: A new classification of the order Perlaria. Canadian entomologist 53: 35^4. Tillyard, R. J. 1923: The stoneflies of New Zealand (Order Perlaria) with descriptions of new genera and species. Transactions and proceedings of the New Zealand Institute 54: Watt, J. C. 1979: Abbreviations for entomological collections. New Zealand journal of zoology 6: Winterbourn, M. J. 1965: Studies on New Zealand stoneflies. 1. Taxonomy of larvae and adults. New Zealand journal of science 8: Winterbourn, M. J.; Rounick, J. S. 1985: Benthic faunas and food resources of insects in small New Zealand streams subjected to different forestry practices. Verhandlungen der Internationale Vereinigung fur Theoretische und Angewandte Limnologie 22: Zwick, P. 1979: Revision of the stonefly family Eustheniidae (Plecoptera) with emphasis on the fauna of the Australian region. Aquatic insects 1: Zwick, P. 1981: Plecoptera. In Ecological biogeography of Australia (A. Keast, Ed.). Dr W. Junk, The Hague. Received 29 May 1996; accepted 27 November 1996