TANE 30, 1984 FROM THE CHICKENS ISLANDS,

by D.J. Court Port Moresby International High School, P.O. Box 276, Boroko, Papua New Guinea SUMMARY

Sixty four species have been collected from Mauitaha, Lady Alice, Middle Rock, Whatupuke, Coppermine and Pupuha Islands which form most of the Chickens Group lying east of Whangarei, Northland. The list includes 20 unidentified species and the majority of these are probably undescribed. Nearly all the named species are native forms expected from Northland coastal forest and seashore. The recently-arrived Australian two-spined (Poecilopachys australasia (Griffith and Pigeon) ) is a most interesting exception; at least one spider ling seems to have ballooned its way to Mauitaha Island; a distance of at least 10 km from the mainland.

INTRODUCTION

The study of spiders in New Zealand native communities is still in its infancy. While there has been great progress by Dr R.R. Forster (Director, Otago Museum) in working through the overall fauna, little is known of spider assemblages on offshore islands and one has to glean records from hundreds of distribution lists for taxa given in Forster's Bulletins (1968—1979). Marples (1956) and Court (1982) have published initial working lists for the Three Kings and Poor Knights Groups respectively. The Chickens Islands (35°85' S, 174°80' E) lie 20-25 km east of Bream Bay, which is to the south of Whangarei Harbour. They are reserves within the Hauraki Gulf Maritime Park and were visited from 30 December, 1981 to 8 January, 1982 by members of the Offshore Islands Research Group (O.I.R.G.). Of the spiders collected during this trip, only two species have previously been recorded from the Chickens. Forster (1973) notes that an unnamed collector gathered the large sheet- weaver Cambridgea foliata and Hexathele kohua from Lady Alice Island (Big Chicken) in December 1953. A number of species have been collected from the nearby Hen Island (Taranga) by E.G. Turbott and other workers. Spiders were obtained directly from webs or retreats, beating foliage, pitfall and malaise traps and sieving of leaf litter. Much of the collecting was carried out at night. The specimens were preserved in 70% ethanol and identified at the Otago Museum by the author (D.J. C.) or by Dr R.R. Forster. They are now lodged in the Otago Museum, Great King Street, Dunedin. 125 A GENERAL ACCOUNT OF THE SPIDERS OBVIOUS ON LADY ALICE ISLAND

As spiders are not well known to most biologists, the following account is given in an effort to familiarise field workers with some of this most interesting group. [It is suggested it be read in conjunction with 'New Zealand Spiders - an Introduction' by R.R. and L.M. Forster (1973)]. On landing on the island, the first place to search is the rocky shore, just at the top of the Nerita zone. Bright white silken retreats in rock crevices are soon obvious. These are constructed of tough silk by the medium-sized Amaurobioides, a brown-black spider with chevron markings on the abdomen and with powerful chelicerae. During the night at low tide the spider waits at the entrance to the retreat with legs extending outwards. It preys on any small invertebrates such as kelp flies and isopods. This spider is often inundated by high tides and so seals itself in with a waterproof silken screen at the retreat entrance. One or two metres above, in much finer, double-entranced silken tubes is Otagoa. This is a smaller, pale-brown coloured spider which runs out at slight disturbances to its web. Both Otagoa and Amaurobioides tend to dwell on rocky cliffs or overhanging branches. These are shaded for at least part of the day and so remain cool and less obvious to predators. Further up, towards the white lichen zone, are the large black Ixeuticus (= Badumna) robustus. These require deep retreats. Because they live in rock or other crevices exposed to bright sun they must be somewhat resistant to high temperatures and dehydration. On extremely hot days, they move right out onto the web lattice and probably avoid the heat conducted through the rock to the inside of the retreat. In and out of the lichens moves the camouflaged, lichen-coloured unnamed . Widely distributed around the seashore, and elsewhere, is the cobweb spider Achaearanea. It is found in a wide variety of situations - rock crevices, pohutukawa roots and trunks and clay banks. The web, about 10 cm across, has guy-lines with viscid silk on the base of strands where they are attached to the substrate. Small crawling along bump into and become attached to the strands. The spider on detecting the disturbance arrives and combs wrapping silk onto the prey. Insects much larger than the spider itself may be captured even though the fangs are small. Steatoda, a relative of Achaearanea, lives in more inaccessible, damper positions above the shore. It is a shiny chocolate- black and juveniles may have pairs of white dorsal abdominal spots, but is often mistaken for a katipo which shows similar prey-catching behaviour. Katipos were searched for in the drier central parts of Spinifex hirsutus growing above West Bay but only old webs were found. This species can be regarded as present on Lady Alice Island but in small numbers.

126 As the ascent of the shore progresses to the first woody vegetation, the large orb weaver Araneus pustulosus becomes obvious, its webs spun on guy-lines that stretch a metre or more. During the day the adults are usually hidden, their colours camouflaging them with bark, stone or whatever substrate their retreat. The ground colour of the dorsal abdominal 'folium' may range from black to 'lichen white'. At night it gains access to the hub of the web either by a silk thread to the edge of the web or by a guy-line directly leading to the centre of the hub. Whilst in the retreat it normally holds the guy-line with a hind claw and by this means it may be alerted to the arrival of prey. Younger spiders may remain in the orb during the day and as they grow, slowly develop a reddish colouring on the inside of the forelegs. In the karaka scrub just above the shore the first of the forest species are seen. Native spiders such as Araneus subcomptus (another well- camouflaged orb weaver) and Hexathele kohua spin their webs. Hexathele may grow very large and constructs bright white funnel-webs in crevices and holes in larger trunks. This species is related to the trapdoors but is in the family and does not actually build a 'door'. Old puriri moth tunnels are often occupied, with the spider 10 cm or more inside, below or above the entrance hole. The spider itself is medium brown, with distinctive light brown chevron markings on the abdomen. In the Utter under coastal forest there are at least 20 species, the most obvious being the speckled brown wolf spiders (Lycosa hilaris ?) and the fast-running Miturga. These two spiders run out from areas being cleared for campsites. The remainder of the litter species are mainly minute, and blend in with disturbed Utter until a few minutes have passed when they start moving around. On low vegetation at night, crab spiders, Sidymella species, move out from their daytime shelters. They take up positions at the bases of branchlets and at the ends of leaves and extend their two anterior pairs of legs in a raptorial pose; they simply wait for prey in this manner, which is seized immediately it comes into contact with the spider. Sidymella is particularly common in the small Uncinia and Carex sedges. Also at night, Clubiona itself may be captured by theridiid spiders. Often at night, the jumping spiders, Trite and other genera, may be seen hanging on 10 cm-long threads attached to the edges of leaves. This group hunts by day with the use of excellent vision and becomes quiescent at night - the hanging behaviour is probably protective against nocturnal invertebrate predators, including other spider species. In the foliage, two medium to small greenish species are very common. Both the crab spider Diaea albolimbata and the small, fast- running dictynid Paradictyna rufoflava may be found on packs and clothing after one has been pushing through vegetation. Diaea appears

127 to have moderate acuity of sight, though nowhere near that of the salticids, and moves below leaves when disturbed. Paradictyna lives in small webs spun under leaves between the leaf edge and midrib. They run out rapidly all over the plant's surface when they are disturbed and are hard to capture. The most distinctive webs in the forest are constructed by Cambridgea foliata. Large silk sheets with a lattice of threads above, extend out from holes in trunks and banks. The spider emerges at night and hangs 'upside down' below the sheet. The silk is so tough that the web 'catches' leaves and heavy twigs from the canopy above without itself being damaged. In these webs (and in those of Araneus pustulosus) may be found the quicksilver spider, antipodiana. This theridiid is much smaller than the host spider and is quite distinctive with its beautiful downward-hanging silvery abdomen. It moves 'stealthily' at one side of the host's web and cuts out small prey such as midges and sandflies without alerting the larger spider. It is therefore termed a kleptoparasite.

ANNOTATED SPECIES LIST

The list of species and notes below, are given firstly, in the sequence of families as found in Part II of Forster (1968) and later bulletins. Secondly, specimens from those families yet to be revised, that is, after the Clubionidae and Mynogleninae, are arranged in the family sequence listed in Part I of Forster (1967). Methods of study of the genitalia were similar to those outlined in Forster and Wilton (1968).

ORDER ARANEAE

SUBORDER MYGALOMORPHA

Migidae Migas cf. borealis Wilton {paradoxus group). One female on puriri bark, 80 cm above ground level. With eggsac attached to inside of exterior wall, 156 eggs. One door on the retreat. Whatupuke Is. One female on kohekohe bark, 1.3 m above ground level, 83 eggs. A smaller, immature example was seen with a door at each end of its retreat. Lady Alice Is.,D.J. C. Internal genitalia, carapace and eyes all corresponded well with Wilton's description. During the identification of these specimens those from the Poor Knights Is. were re-examined. It seems that two species groups of trapdoor spiders are present on Tawhiti Rani Is. As a result it could be expected that spiders of the sandageri group would also be present on the Chicken Is.

Dipluridae Subfamily Diplurinae Aparua taranga Forst. Six females (and immature males?). Juvenile in pitfall trap. Found in 5-10 cm deep silk-lined tunnels sloping slightly out of the vertical in heavily littered ground

128 under old kanuka. Opening of retreats without silken barrier of any kind and some tunnels wishbone shaped with one of the branches of lesser diameter. Most tunnels single. Lady Alice Is.,D.J. C. Specimens have female internal genitalia identical with A. taranga of Hen Is. (Taranga) named from specimens collected by E.G. Turbott in 1959. Subfamily Hexathelinae Hexathele kohua Forst. Nine females collected. Common and in all sizes in rock, bark and insect burrows. No males seen. During a night search an immature 4th or 5th instar and a mature (?) female were seen well away from any web on tree trunks. Lady Alice Is.,D.J. C. Not seen on Whatupuke Is. although searched for. (See discussion) Previously collected on Big Chicken Is. Dec. 1953 by an unnamed collector and by E.G. Turbott, Dec. 1927, and H. Abraham, May 1949 on Hen Is. Subfamily Macrothelinae Porrhothele cf. quadrigyna Forst. Five females and 5 younger specimens. One hundred and three second instar spiderlings from one eggsac. Extensive silk funnels leading into crevices in a rockslide in heavy shade under coastal forest. Above Starfish Bay, Whatupuke Is.,D.J. C. Not seen on Lady Alice Is. although searched for. Only two of the recognisably female specimens were mature and of these, the slightly smaller specimen may have undergone one less moult. There may be a trend where further moults increase the number of receptacular lobes. However another two females apparently large enough to be mature had no developed genitalia. This was true also for Poor Knights Is. specimens. The arrangement of the zones of sclerotisation at the bases of the receptacular lobes may prove to be a better taxonomic character than the actual number of lobes present (R.R.F. pers. comm.). Fig. 1.

SUBORDER ARANEOMORPHA

SUPERFAMILY Subfamily Desinae Ixeuticus (—Badumna) robustus (L. Koch). Two females, one immature male. Under kanuka bark. Web cribellate but not externally distinct. Also in cracks in rock at beginning of white lichen zone above the shore. Lady Alice Is.,D.J. C. Subfamily Myroninae Otagoa cf. nova Forst. Mature female, three mature males, immature specimens, Lady Alice Is.,D.J. C. Immature male, Middle Rock. D.J. C. Mature females, 4 mature males. (The largest, with a body length of 9 mm) Whatupuke Is.,D.J. C. Found on the shore in silk retreats in crevices. Common on coastal rock just above Nerita zone but below white lichens. The spiders were quite varied in size, the male palp identical to nova Forst.

129 Te Huka, Tom Bowling Bay

Fig. 1. Internal genitalia of North Auckland and offshore island Porrhothele (Dipluridae). Those of P. quadrigyna from Te Huka and Kohukohu are redrawn from Forster and Wilton (1968). One of the preparations of the Tawhiti Rahi Island (Poor Knights Group) form is redrawn from Court (1982).

130 Gohia, undescribed species. One female from pitfall trap under coastal forest. Lady Alice Is. There are 4 species described, none of them from further north than the south of the South Island - but they probably occur throughout New Zealand. Gasparia, undescribed species. 1. One female. Beaten from Astelia Lady Alice Is.,D.J. C. The front two pairs of legs possess very stout spines reminiscent of certain harvestmen. Probably a raptorial type of predator. Gasparia, undescribed species. 2. Mature female. Litter under kanuka. Lady Alice Is., D.J. C. Front two pairs of legs not spined as with species above. Twenty two Gasparia spp. have been described from New Zealand. Paradictyna rufoflava (Chamb.) Eight females, one male, Lady Alice Is.,D.J. C. One female Lady Alice Is., B.W. Hayward. One female Lady Alice Is., C. Ward. One female Whatupuke Is.,D.J. C. One female Whatupuke Is., E. Cameron. One of the females was with a parasitised eggsac and another had 21 eggs in its eggsac. The specimens were all attributable to this one species, even though they showed a considerable range in colour pattern (i.e. with or without dark or pale abdominal spots). Generally distributed on forest tree leaves, especially on partially-shaded understorey broadleaf tree species, such as mahoe. Also found on Astelia. Beaten from most forest vegetation. Amaurobioididae Amaurobioides cf. pallidus Forst. Six mature females, one male, 2 mm, plus female with accompanying courting male. One eggsac with 64 eggs and embryos, another with 38 embryos. Restricted to crevices of seashore rocks occupying a zone, 1-2 m directly above the upper level of the 'Nerita, zone and exposed tidal splash; occasionally submerged. Lady Alice Is.,D.J. C. On disturbance, some spiders raced over the rock surface then dropped only 10 cm on escape threads. The epigynum and palp are quite similar to pallidus but with the abdominal pattern different and darker compared with the type description of the spider from Wellington. The northern form could yet prove to be distinct.

SUPERFAMILY AMAUROBIOIDEA Neoramia undescribed species. Four females, one immature male. Collected together with Reinga sp. from under logs and from loose soil and rocks. Lady Alice Is.,D.J. C. This undescribed species is possibly the smallest member of the , being only 3 mm in length. Cambridgea fasciata L. Koch. One male from a 10 cm - wide web between rocks just above the beach. Lady Alice Is.,D.J. C. Found previously on Hen Is., Jan. 1968 by M. Grantham.

131 Cambridgea foliata (L. Koch.). Two females, one immature male, one male. Large sheet webs extending from holes in trunks and rotten branches. The web of the male was 1.25 m in width and 1 m. above ground level. Lady Alice Is.,D.J. C. Found previously on Lady Alice Is., Dec. 1953, by an unknown collector (Forster 1973) Amphinectidae Reinga cf. apica Forst. Eight females, two immature males, Lady Alice Is., D.J. C. Three females, one immature male, Whatupuke Is.,D.J. C. Reinga builds Ixeuticus-like webs in crevices in rocks just above the extreme high water spring mark but also throughout the coastal forest under logs and branches. Two of the Whatupuke Is. specimens had eggsacs, one with 40 eggs, the other with 33 second instar spiderlings. This collection fits best with the description of R. apica Forst. collected from Cape Reinga by D.R. & R.R. Forster, 7 Jan. 1967. Although several other species, e.g. R. media Forster from Great Barrier Is. and R. waipoua Forster from Waipoua forest, have been named from localities closer to the Hen and Chickens Group, the Chickens Is. form may yet prove to be distinct. Neolanidae Neolana cf. septentrionalis Forst. One female with eggsac containing 36 eggs. Four females either immature or newly moulted and not sclerotised enough for specific determination. On southern side of large boulders under coastal forest. Occasional webs on the trunks of large pohutukawa trees. Above Starfish Bay, Whatupuke Is., D.J. C. The internal genitalia were as for N.septentrionalis Forst. named from Hen Is. specimens but the epigynum was closer to N. pallida of the eastern Bay of Plenty. 'Incertae sedis' Aorangia mauii Forst. Seven females, one male. Small sheet webs above Utter layer under kanuka scrub. On level ground. The webs, normally almost invisible were made obvious by all the shed kanuka petals resting on them. Lady Alice Is., D.J. C. This is the first collection of the male. Aorangia is a litter spider and widespread in northern regions. Cycloctenidae Cycloctenus undescribed species. Two immature males. Amongst stones, logs and Utter under pohutukawa forest in the valley above Starfish Bay, Whatupuke Is.,D.J. C. Gnaphosidae Hypodrassodes undescribed species, probably of the dalmasi group. Three females, two immature males captured in pitfull traps placed near shingle slides at the top of the beach at South Cove. Other individuals were seen at the edges of rotten logs where they had spun fine silken retreats; Lady Alice Is.,D.J. C. Internal genitalia match well with the illustration of the Auckland form given in Forster (1979, fig. 203) This genus is common in the Auckland area. Taieria undescribed species. One female pitfall trap, one male kohekohe coastal forest Utter, Lady Alice Is.,D.J. C. The species nearest in recorded distribution is the November, 1971 collection of

132 D.J. C. from Red Mercury Island which Forster places tentatively in T. miranda Forst. Scotophaeus pretiosus (L. Koch). One female, .one immature male, pale in colour. From loose bark of kanuka. Some larger specimens were seen but escaped (these may have been a species of Hypodrassodes) Lady Alice Is.,D.J. C. Also found on Mokohinau Group, Cuvier and Whale Islands. This species is possibly equivalent to Herpyllus blackwalii (Thorell) from the northern hemisphere. See p. 66 of Forster (1979) and Locket and Millidge (1951,1953). Hemicloea rogenhoferi L. Koch. One female. Under bark of large dead kanuka. It was guarding a bright, matt-white lenticular eggsac with 145 spiderlings. Lady Alice Is.,D.J. C. This species is widespread in Northland and is assumed to have been introduced from . Clubionidae Clubiona peculiaris C.L. Koch. Three females, two males. The females were collected at night on seashore and forest vegetation. The males were beaten from pohutukawa. Lady Alice Is.,D.J. C. C. peculiaris is very widespread in New Zealand. Clubiona consensa Forst. Two females, 6 males. Captured on understorey vegetation at night. Immature spiders probably of this species from litter samples under kanuka. Lady Alice Is., D.J. C. C. consensa is also very widespread in New Zealand. Subfamily Mynogleninae Mynoglenes. cf. major Blest. One female, coastal vegetation. Lady Alice Is.,D.J. C. The cleared and mounted genitalia appeared very similar to the figure for the type description in Forster and Blest (1979.) Although the spider is rather smaller than the described form it fits best into M. major at present. Subfamily Linyphiinae Undescribed genus and species. Four females, one immature male, Lady Alice Is.D.J. C. Whatupuke Is.,D.J. C. This delicate long-legged species builds extremely fine sheet webs in association with the orb-weaving anapid Pseudanapis insula amongst well- shaded leaf utter. (For this form of linyphiid, Forster uses the manuscript name of Pahora to replace ) Ascuta undescribed species, (part '') Two immature specimens from kanuka forest leaf litter. Lady Alice Is.,D.J. C. This is an undescribed 'Pounamuid', (see Court 1982) Dr R.R. Forster is at present revising this group of interesting 6-eyed spiders. Segestriidae Ariadna unidentified species, undescribed? One female with 50 eggs in sac. One female with 40 eggs, three females without eggsacs. Lady Alice Is.,D.J. C. One female with 21 eggs in sac, three females without eggsacs Whatupuke Is.,D.J. C. Ariadna constructs tubular silken retreats especially in

133 abandoned beetle holes in rotten wood and bark, but also in rock and soil crevices near the shore. This group is not revised. Gippsicola unidentified species, undescribed? One female, two immature females in beetle holes in association with Ariada. The spiders were found from just above ground level to 3 m. above ground on only one rotten trunk under pohutukawa forest. No eggsacs were observed. Lady Alice Is.,D.J. C. Unlike AAriadna ,th e open exterior of the silk tube has up to 17 trip lines radiating from its edge. This is the genus 'Segestria' noted by Forster (1967) Lycosidae Lycosa hilaris L. Koch. Three females, one immature male collected from leaf litter on floor of tent during midday. Two of the females were carrying spiderlings which clung to the females' abdomens. One brood included 35 spiderlings, the other only 6 spiderlings. Lady Alice Is.,D.J. C. One female, Lady Alice Is., B.W. Hayward. Both of the above- mentioned females had probably lost the majority of their spiderlings (Forster and Forster, 1973, report 80-135 spiderlings in lycosid broods.) Pisauridae Dolomedes cf. minor L. Koch. One female found in a Cambridgea web which was tattered and without the spider. This web was adjacent to a small stream. One female with eggsac was found at night among ground cover plants under kanuka. The eggsac contained the large number of 582 eggs. One penultimate male in Spinifex hirsutus at West Bay. Lady Alice Is.,D.J. C. Sidymella angularis (Urq.). Eight females, two males captured at night on kohekohe trunk and on other vegetation such as sedges and grasses. Lady Alice Is.,D.J. C. One female from Meryta sapling, Lady Alice Is., 6 Jan.1982. R.E. Beever. S. angularis has two projections on carapace. Sidymella angulata (Urq.). One female, three males collected from sedges and grasses along tracks and bush margins. Lady Alice Is., D.J. C. S. angulata has no projections on the carapace. Apart from carapace differences angularis and angulata seem similar in appearance and habitat. It is not yet clear if these two species use different microhabitats or show any distinguishing behaviour such as catching different prey species. They have been collected on a number of other offshore islands. Diaea albolimbata L. Koch. Three females from leaf tips of shrubs under kanuka forest. Lady Alice Is.,D.J. C. One immature female, Middle Rock,D.J. C. This species has a very wide distribution in New Zealand. Miturga unidentified species, undescribed? One female, Lady Alice Is.,D.J. C. Penultimate male from loose leaf litter, soil and rocks. This species runs very rapidly. Whatupuke Is.,D.J. C.

134 Achaearanea cf. veruculata (Urq.). Three females, three immature females, 4 males. Females collected from pohutukawa and kanuka trunks, also from rock crevices above the shore. Egg sacs were present in each web. The males were gathered at night while they roamed through low vegetation under kanuka. Lady Alice Is.,D.J. C. Atkinia cf. nana (Cambridge). One male, one immature male from litter under kanuka forest on the summit ridge of Lady Alice Is.,D.J. C. This is a minute brown theridiid related to the genus . Argyrodes antipodiana, Cambridge. Two females, one male kleptoparasitic in Araneus pustulosus web. Lady Alice Is.,D.J. C. This species is common in larger spider webs throughout the Auckland area and feeds on small insects such as midges trapped in the host's web. Episinus undescribed species? Two females, one male on single threads at night in a stream valley. Lady Alice Is.,D.J. C. Also collected amongst stones, logs and litter under pohutukawa in valley above Starfish Bay, Whatupuke Is.,D.J. C. New Zealand forms of Episinus were thought to spin only single threads for prey capture but the author has seen recently in the Waikato two Episinus in tawa forest with snares identical to that shown for a British species by Bristowe (1958). It seems that they are extremely sensitive to vibrations and dismantle their snares on being disturbed. Icona undescribed species. Eight females, 4 males. Collected from single strands suspended between subcanopy vegetation under coastal forest. Lady Alice Is.,D.J. C. One female had spun a single eggsac within a lattice of threads at the top of a Geniostoma shrub under kanuka. The eggsac was tear• drop shaped and of bright, matt white silk. The spiders are of varied colour pattern with the abdomens having combinations of either yellow or red with brown, black or white, often arranged in a dorsal stripe. Court (1982) noted that Icona on Tawhiti Rahi were associated with orb webs. No such association was seen on Lady Alice Is. Latrodectus katipo subspecies atrititus Urq. Webs only were identified from Spinifex hirsutus growing at West Bay, Lady Alice Is.,D.J. C. Steatoda undescribed species? One female. Under stones at the base of seashore cliff. Middle Rock.D.J. C. Steatoda species are common in coastal habitats but like other theridiids have not been revised. Ulesanus (=Phoroncidia) quadratus Camb. Two females, one male in single threads suspended between coastal forest trees at night; beaten from the ground fern Blechnum fraseri Lady Alice Is.,D.J. C. Oxypopes gregarius (Urq.). One immature male. Beaten from Carmichaelia aligera West Bay, Lady Alice Is.,D.J. C. 135 Mimetus unidentified species. One male suspended between trees at night on a single thread. Lady Alice Is., D.J. C. Four female (?) immature. Specimens collected from the web of a large Porrhothele. Whatupuke Is., D.J. C. Mimetus is known to prey on theridiids but may perhaps prey also on other spiders. Araneus invisibilis (Urq.). Many females, one male. Orb webs in the narrow coastal strip between shore and woody vegetation. Lady Alice Is.,D.J. C. Two females Pupuha Is., Lin Roberts. These specimens match-well with Urquhart's type of invisibilis that was collected from near Dunedin. Urquhart also described Epeira saxatilis from a collection of immature spiders from Waiwera, these are probably the same species (Forster et al in prep.). Araneus pustulosus (Walck). One female collected. Common seashore rocks from lichen zone to overhanging vegetation, such as Coprosma repens, Hymenanthera and flax (Phormium tenax). Seen also in tea-tree vegetation. Lady Alice Is.,D.J. C. Araneus subcomptus (Urq.). Six females, one immature male. Orbwebs spun between low vegetation and forest subcanopy. Lady Alice Is., Whatupuke Is., Middle Rock,D.J. C. Araneus viriditus (Urq.). Two females, one immature male Lady Alice Is. Collected by A. Grace, M. Potter &D.J. C. The web of the immature male had a 2 cm high vertical stabilimentum directly above the hub of the orb. A more immature spider was seen without a stabilimentum. The mature female collected by Anne Grace differed from the common pea green form. It did not have the anteriodorsal marginal marking on the abdomen and the legs were coloured reddish brown at the joints. But the structure of the epigynum in the preserved specimen could not be distinguished from that of the other female. Argiope protensa Koch. One female petrel scrub, Keyhole Stack. J. McCallum Leucauge dromedaria (Thorell). One female, one male. Orb web of female above web of male in flax scrub adjacent to streamlet. Immature spiders seen. Lady Alice Is.,D.J. C. Nanometa unidentified species. One immature female under coastal forest in association with anapids above leaf litter. Lady Alice Is.,D.J. C. Orsinome lagenifera (Urq.). One female, one immature female. Horizontal orbs above small streamlet in thick coastal forest. Lady Alice Is., D.J. C. Poecilopachys australasia (Griffith & Pigeon). One female summit of Mauitaha Is., A.E. Wright. The first record of Poecilopachys in New Zealand is late 1969 from Pt. Chevalier, Auckland (K.A.J. Wise pers. comm.). Since this date the spider has spread both north and southwards. This Chickens Group record is testimony to its remarkable dispersal. The position in which it was 136 found is most suggestive of spiderlings being blown from the mainland by the westerly wind usually prevailing. Tetragnatha. sp. Two females, one male Lady Alice Is.,D.J. C. Ten Lady Alice Is., B.W. Hayward. This species belongs to the group of native tetragnathids described by Urquhart in 1890; e.g. T. flavida or T. multi-punctata. It is impossible to work from his descriptions until the spiders are compared with the types. Zearchaea cf. clypeata Wilton group. Two females. Pitfall trap under kanuka. Lady Alice Is.,D.J. C. Pseudanapis insula (Forst). Three females, one immature female, one male, two immature males collected directly from webs above litter under coastal forest. Ten kohekohe/karaka litter sample. One immature female coastal scrub litter sample. Lady Alice Is.,D.J. C. One of the spiders had captured a weevil equal in size to the spider. It was sent to Dr G. Kuschel who placed in his new genus Andracalles Fig. 2. Chasmocephalum armatum Forst. Two females, pohutukawa litter, Lady Alice Is.,D.J. C.

Fig. 2. Web of Pseudanapis insula (Anapidae). Constructed amongst coastal forest leaf litter, Lady Alice Island. The basal diameter of the modified orb web measured 40 mm. with the orb centre 8 mm vertically above the orb margin. The orb consists of between 50 and 60 spirals of viscid silk.

137 Mysmena sp. One immature male pohutukawa Utter, Lady Alice Is., D.J. C. Testricellidae Unidentified 'textricellid' One female, one male kanuka leaf litter, Lady Alice Is., D.J. C. Salticidae Unidentified 'house hopper' species. One female, beach, Lady Alice Is.,D.J. C. The single specimen captured was the only one seen on the island. It was later realised that, as it had been caught near the boat unloading point on the beach, it could have been brought to the island amongst camp gear, or in a crevice of one of the aluminium dinghies used by the party. Forster (1973) considers that this may have been introduced to New Zealand from Australia. Although it is very common in New Zealand there seems to be no description of it in the literature. Trite auricoma (Urq.) Two females, one immature female, two males under kanuka bark Lady Alice Is.,D.J. C. Coastal forest, Whatupuke Is.,D.J. C. Coastal forest, Coppermine Is., J.E. Beever. This is the most common of the salticids. Trite planiceps Simon. One immature female, one male, one immature male at night hanging on silk strands attached to leaf edges. Lady Alice Is.,D.J. C. Trite ? sp. Four females, 5 males. At night hanging on silk strands attached to leaf edges. Lady Alice Is.,D.J. C. Unidentified 'seashore' species. One female, Middle Rock. B.W. Hayward. One immature female Whatupuke Is.,D.J. C. This lichen -coloured species is commonly found in the lichens above the spray

DISCUSSION

A brief glance at the above species list will show that little is known about quite a large number of spider taxa. Many of the easily-recognised families such as the Salticidae, and Lycosidae have not been revised this century. Further, even with Dr R.R. Forster's new revisions of important native groups with hundreds of species being described or re-described, it is often difficult to identify a number of northern offshore island forms. This of course adds extra interest to collections from localities, such as the Poor Knights or Chickens Groups. The problem is quite similar to that stated by Watt (1983) when he referred to the research required for beetle , life history and ecology. The following discussion deals briefly with two spiders, Porrhothele and Pseudanapis, which are at opposite ends of the size spectrum and are little-known. Porrhothele: The northern species, P. quadrigyna is apparently widely

138 distributed, from Tom Bowling Bay (Forster and Wilton (1968) to Great Barrier Island, (Court 1973). Few specimens have been collected despite its large size and the presence of the large population of Auckland city nearby. The spider seems rather restricted to certain locations but is quite common within these locations. Examination of the female internal genitalia show that 'quadrigyna' exhibits marked variation in number of receptaculae. (Fig. 1.) More collecting and dissection will be required to determine whether there is one variable northern species, or whether the Poor Knights and Chickens populations are truly distinct. The local distribution of Porrhothele is also of interest, especially when compared with that of the related Hexathele. On Great Barrier, a large island, both genera exist close together, yet on the smaller Tawhiti Rahi Island. (Poor Knights Group) and Whatupuke Island (Chickens Group) only Porrhothele is present. It is a remarkable situation because on neighbouring Lady Alice (Chickens Group) only Hexathele occurs even when it would seem to provide a habitat quite suitable for Porrhothele. Tawhiti Rahi and Whatupuke would seem to be suitable for Hexathele. The 'missing' genera may have been overlooked but these are large spiders with quite conspicuous webs and this possibility is unlikely. As with the question of speciation in northern Porrhothele, the explanation of the above will first require many more observations. Pseudanapis: This minute spider, together with many other small spider species, is probably quite important in food chains occurring in forest litter. The population observed on Lady Alice was quite dense, with about 20 orbs per square metre, yet its small size allows it to be very easily overlooked. The web is an intricately woven upward-pointing cone which is actually a modified horizontal orb web, with the hub pulled upwards (Fig. 2). The webs are easily visible only when illuminated with oblique shafts of sunlight that penetrate the forest canopy; the slightest disturbances causes the spiders to drop down off the web and into the litter. Their prey is wrapped in a manner analogous to Aradid orb weavers. Porrhothele and Pseudanapis are but two of the offshore island spiders that would reward further study. The Chickens Islands fauna can be regarded as mainly indigenous. The adventive species have established where plant communities have been disturbed, e.g. Hemicloea under kanuka bark, or where a habitat exists but is not filled by indigenous species e.g. Ixeuticus in exposed seashore crevices subject to heat, and Poecilopachys which constructs webs between wide canopy gaps. Of the indigenous species it is the array of mainly undescribed forms from leaf litter that holds particular interest, e.g. Ascuta, Atkinia, Cycloctenus, Gasparia, Gohia, Mysmena, Neoramia, Pahora) Taieria, ^Textricella' and Zearchaea species plus many others that are probably present but not yet collected. Any island that has coastal forest with deep and humid leaf litter will support a similar range of fauna.

139 ACKNOWLEDGEMENTS

I particularly wish to thank Dr R.R. Forster for much assistance; Firstly for the provision of working facilities at Otago Museum; secondly, for very many useful suggestions and comments, and for identifying more difficult taxa. Members of the Offshore Islands Research Group have assisted in the collection of spiders and I thank the organisers of the trip to Lady Alice Island. Dr R.V. Grace ensured safe transport to other islands in the Chickens Group.

REFERENCES

Bristowe, W.S. 1958: 'The World of Spiders'. (The New Naturalist) Collins. 304 p. Court, D.J. 1973: Spider populations of Great Barrier Island. Tane 19:179-188. Court, D.J. 1982: Spiders from Tawhiti Rahi, Poor Knights Islands, New Zealand. Journal of the Royal Society of New Zealand 12:359-371. Forster, R.R. 1967: 'The Spiders of New Zealand. Part I.' Otago Museum Bulletin No. 1. Forster, R.R. 1970: 'The Spiders of New Zealand. Part III.' Otago Museum Bulletin No. 3. Forster, R.R. & Blest, A.D. 1979: 'The Spiders of New Zealand Part V.' Otago Museum Bulletin No. 5. Forster, R.R. & Forster, L.M. 1973: 'New Zealand Spiders - an Introduction'. Collins. Forster. R.R. & Wilton, C.L. 1968: 'The Spiders of New Zealand. Part II.' Otago Museum Bulletin No. 2. Forster, R.R. & Wilton, C.L. 1973: 'The Spiders Of New Zealand. Part IV.' Otago Museum Bulletin No. 4. Locket, G.H. & Millidge, A.F. 1951: 'British Spiders Vol. I.' Ray Society, London. Locket, G.H. & Millidge, A.F. 1953: 'British Spiders. Vol. II.' Ray Society, London. Marples, B.J. 1956: Spiders from the Three Kings Islands. Records of the Auckland Institute and Museum 4 (6): 329-342. Watt, J.C. 1983: Beetles (Coleoptera) Of Auckland Tane 29:31-50.

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