The lice of the Tristan da Cunha Archipelago ( Insecta : Phthiraptera )

All the louse species reported in the literature from the Tristan da Cunha archipelago have been compiled, listed and discussed, including five additional species records based on material recently collected or identified in previous collections. A total of 54 louse species (including 6 records identified at the generic or subgeneric level only), belonging to 21 genera, have been listed together with their hosts: 20 bird species and one mammal. A brief discussion on the history of louse collections made on and around the archipelago, and detailed louse records from the four main islands are also given.


Introduction
The Tristan da Cunha archipelago consists of four main islands and a few islets that lie in the central South Atlantic, approximately 2,800 km from South Africa and 3,200 km from the nearest point of South America.Three of the islands, Tristan da Cunha, Nightingale (with its associated Middle and Stoltenhoff Islets) and Inaccessible, lie within 40 km of each other around 37°S, 12°W, while the fourth, Gough Island, is positioned some 426 km further to the south-south-east of Tristan da Cunha, at 40°18' S, 09°56' W (Figure 1).
The islands are all of volcanic origin, with Tristan da Cunha still being active; the most recent seismic event of significance having occurred in July 2004 as a result of a submarine eruption, some 25 km out to sea from the 1961 eruption at the Edinburgh settlement (BROCK, 2004).Tristan da Cunha is also the largest of the group, measuring close to 100 km² in area and 40 km around its conical perimeter, with the central peak rising to about 2060 m.It is the only island of the archipelago with a permanent human settlement of about 275 people, holding the status of being 'the most remote inhabited island on Earth'.The second largest of the islands is Gough with an area of 65 km², followed by Inaccessible (area 14 km²) and Nightingale (approximately 3 km²).Two of the islands are protected areas, Gough as a Wildlife Reserve, and Inaccessible as a Nature Reserve, both having been awarded World Heritage Site status.Accordingly, access to them is restricted, especially at Gough where it is principally limited to the personnel servicing the South African weather station, and the occasional group of scientists carrying out research projects (HÄNEL et al., 2005).

Birds and mammals
The islands are known primarily for their bird life, rating globally amongst the most important areas for breeding seabirds.As many as 28 breeding bird species, with at least 34 vagrant species arriving at the islands in varying degrees of abundance, have been recorded from the entire archipelago (see Appendices 2, 3).Among the breeding birds, 22 species are seabirds of which, the largest proportion are petrels and albatrosses (Order Procellariiformes).Four seabirds, the Atlantic yellow-nosed mollymawk (Thalassarche chlororhynchos ( Thalassarche chlororhynchos ( Thalassarche chlororhynchos GMELIN, 1789)), the Tristan albatross (Dio medea dabbenena MATHEWS, 1929), the Spectacled petrel (Procellaria conspicillata GOULD, 1844), and the Atlantic petrel (Pterodroma incerta ( incerta ( incerta SCHLEGEL, 1863)) are endemic to the archipelago.The remaining six species are all endemic landbirds.Except for poultry living at Tristan da Cunha, there is no other introduced species in the archipelago (HÄNEL et al., 2005; RYAN & GLASS, 2001;GLASS & SANDERS, 2006).For this paper, we have extracted all bird records for the archipelago, as well as the nomenclature of bird taxa, from RYAN &GLASS, (2001) andHÄNEL et al. (2005).
The native mammals breeding on the islands consist of two marine species, the Subantarctic fur seal Arctocephalus tropicalis ( Arctocephalus tropicalis ( Arctocephalus tropicalis GRAY, 1872) and the Southern elephant seal Mirounga leonina (LINNAEUS, 1758).Apart from humans that have settled on Tristan and visit the other islands of the archipelago, at least 10 other terrestrial species have been introduced which include vermin (mice and rats), domestic animals (dogs and cats) and livestock (cattle, sheep, pigs, donkeys and horses) (see Appendix 3), all of which are restricted to Tristan da Cunha, with the exception of mice that also occur on Gough Island.

Lice
Together, the birds and mammals of the Tristan da Cunha archipelago represent potential hosts for many louse species (Order Phthiraptera).Given that each seabird species is known to host lice belonging to several genera (CLAY & MOREBY, 1967;PILGRIM & PALMA, 1982;PRICE et al., 2003), the number of louse species represented at the islands can be expected to be high.In an attempt to fill some of the gaps about the invertebrate knowledge relating to Tristan da Cunha and Nightingale -the island more regularly visited -a brief project was initiated in 2005 that aimed at empowering the people of Tristan da Cunha with information and collecting techniques (HÄNEL, 2005).As part of that project, an insect collection was made at Nightingale Island, including lice from birds.

Collections of Tristan da Cunha lice
The following institutions (with their acronyms) are known to hold and care for louse material collected from hosts at the Tristan da Cunha archipelago: MONZ: Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand.NHML: Natural History Museum, London (formerly British Museum (Natural History)), England.

Materials and methods
In this paper we have compiled all available information relevant to the lice found on hosts from the islands of the Tristan da Cunha archipelago.This is based on published and un-published information, and specimens from the 2005 collection as well as older material that was re-examined (principally housed in the MONZ).The 2005 collection comprised 27 lice of seven different species.These were obtained from Nightingale Island by hand searches from three bird species, namely one dead Broad-billed Prion Pachyptila vittata (FORSTER, 1777), a pile of dead Great Shearwaters Puffinus gravis (O'REILLY, 1818), and two Yellow-nosed Albatrosses Thalassarche chlororhynchos (GMELIN, 1789), (one juvenile carcase and one live adult).All lice were preserved in 70% Ethanol, of which 22 specimens were subsequently mounted on glass slides following the technique in PALMA (1978), and positively identified by PALMA (1978), and positively identified by PALMA R.L.P.Among the 27 lice, 10 specimens were deposited in the University of Glasgow collection for DNA analysis, three specimens in the MONZ and the remaining material in the NRTC.

Results
Included in this paper are five new records of species for the archipelago, four new records of species for Nightingale Island, and three new records for Gough Island.Most of the new records are the result of brief collections made at Gough Island by Richard Cuthbert during [2000][2001]

History of louse collections and publications
The history of the people who collected lice at the Tristan da Cunha archipelago and the fate of their collections, together with their repository institutions, have not been entirely unravelled.However, the information available is fascinating, showing that some of the earliest louse records from Southern Ocean islands may have been from or around Tristan da Cunha.
The earliest collection appears to be that made during October-November 1901 by the Deutsche Südpolar-Expedition 1901-1903and reported by ENDERLEIN, (1917).The records are all of lice collected from petrels and albatrosses at sea while the vessel travelled past Tristan da Cunha towards South Africa.
The next collection, the first made on the islands proper, was by a P. Bonomi, who took lice from albatrosses and petrels at Tristan da Cunha in 1904, and deposited them in the SAMS at Cape Town.In 1912, Dr. Péringuey submitted the louse material for identification to James Waterston in England.Subsequently, an account was published by WATERSTON, (1914)  In 1922, the Quest visited all the islands of the Tristan da Cunha archipelago and set ashore parties to investigate and collect specimens.Amongst them was the ship's naturalist George Hubert Wilkins who, on going ashore at Nightingale was described as follows (WILD, 1923): "… Mr. Wilkins kept shooting birds on the way up, but we had great difficulty in finding them in the grass.We were drenched to the skin ... sliding down the soaking rotten earth, stumbling blindly through the long grass and slipping into the holes".Whether purposefully or inadvertently, some louse specimens remained on the preserved skins made from that collection, including three specimens of Perineus circumfasciatus KÉLER, 1957 from a Sooty albatross, LER, 1957 from a Sooty albatross, LER Phoebetria fusca, dated 25 May 1922, now lodged in MONZ (PALMA & PILGRIM, 1988: 583).
It was during 1937-1938 that the first and so far the only thorough entomological study was made of the three northern islands by the Norwegian Scientific Expedition to Tristan da Cunha.The terrestrial zoologist, Dr. Yngvar Hagen, made a collection of the invertebrates, which included lice from birds at Tristan da Cunha, Inaccessible and Nightingale.The specimens were deposited in ZMON, and some duplicates in NHML.Two publications on lice emanated from that collection, the first part being by CLAY, (1957) listing the identified specimens, and the second by TIMMERMAN, (1957) (1988: 584).
In 1949-1950, a collection of lice was made by Mrs. M. K. Rowan from birds at the three northern islands, later deposited in the NICD at Johannesburg, South Africa.KÉLER, (1951KÉLER, ( , 1952) ) published two accounts of the species included in that collection: the first paper contains the descriptions of two new louse species found on the flightless and endemic Inaccessible rail, Atlantisia rogersi LOWE, 1923, while the second includes detailed redescriptions of several louse species collected from petrels, and descriptions of two new species from penguins.
Hugh Francis Ivo Elliott, an officer of the British Colonial Service, assumed duty as Administrative Officer of Tristan da Cunha on 31 January 1950.He collected birds on the islands of the archipelago, including Gough Island, for the British Museum (Natural History) -now NHML -during 1951-1952.Several samples of lice were extracted from these birds, which are now deposited in the NHML, and most have been studied and reported in several publications (e.g.CLAY, 1957;KÉLER, 1957;TIMMERMANN, 1954TIMMERMANN, , 1957;;PALMA & PILGRIM, 1988, 2002), which include two species, Austromenopon elliotti TIMMERMANN, 1954 andLongimenopon elliotti TIMMERMANN, 1957, named after H.F.I.Elliott (see Table 1 & Appendix 1).
During the summer of 1955-1956, the focus shifted to Gough when a systematic study of the island was made by the Gough Island Scientific Survey.The expedition's leader, Martin W. Holdgate, was the entomologist who carried out the investigations concerning invertebrates.His collection of lice was also deposited in the NHML and reported in some publications (e.g.KÉLER, 1956;HOLDGATE, 1965;PALMA & PILGRIM, 2002).However, the most comprehensive collection of lice from the island group was made in 1985 by Robert W.  2001;JONES et al., 2003b).A small collection of lice from birds was made as part of that survey, but no report has hitherto been produced about them.Our attempts to study that collection and to include it in this paper failed despite repeated efforts to locate it in the NHML.This institution appears the most likely repository considering that JONES et al., (2003b) indicate that all GITIS samples were "… returned to the UK to be identified …" and, in their acknowledgments, they list several of the NHML staff members for their help and advice.

Louse records
In this paper, we have added five new records of species for the archipelago: The two larger islands, namely Tristan da Cunha and Gough, have been more thoroughly and frequently sampled and therefore, have the highest number of louse species recorded, i.e. 32 and 33 species each respectively.Nightingale and Inaccessible Islands being much smaller and less sampled, have 13 and 11 louse species recorded respectively (see Table 1).
Among the 54 louse species listed in this paper, three (5.5%)can be considered endemic to the archipelago: two species parasitic on the Inaccessible rail and one on the Tristan thrush.The great majority, 50 species (92.6%), are native to the archipelago, and one species was introduced by humans (see note 7).The level of endemism is related directly to the number of endemic terrestrial bird and mammal species represented at the island.The situation reflected by the louse fauna of the Tristan da Cunha Archipelago is no different from that at other oceanic islands (see HORNING et al., 1980;PILGRIM & PALMA, 1982;MARRIS, 2000;PALMA & JENSEN, 2005).

Hosts
In terms of louse hosts, the archipelago potentially has 77+ species, being 64+ birds (28 breeding, 34+ vagrants and two+ alien introductions); and 13+ mammals (two native and 11+ alien introductions) that occur on the islands (see Appendix 2 & 3).Among these, 21 host species have lice recorded from them, of which 19 are breeding birds (17 seabirds and 2 landbirds), one is a vagrant bird and one is a mammalian host.(see Table 2 and Appendix 2).The Black-browed mollymawk, Thalassarche melanophrys ( Thalassarche melanophrys ( Thalassarche melanophrys TEMMINCK, 1828), counted here as the single vagrant host, is a frequent visitor that may have been a breeding species on Tristan da Cunha at the time that it was sampled (1937)(1938).The single record of a mammal louse refers to human headlice, although it may now be absent from the islands (see note 7).Surprisingly, apart from the single incident involving humans, there are no records of lice from the several mammal species of the archipelago, despite the fact that mice have been well established at Tristan da Cunha and Gough since early 1900, followed by rats at Tristan and farm animals (temporally at Gough between the 1950's and 1970's and permanently at Tristan) (see Appendix 3).The apparent absence of lice may be due to lack of collecting effort, or that the mammal populations are indeed free of lice because their ancestors arrived free of lice to the islands, an event called "missing the boat", or that they had lice at their arrival but subsequently they became extinct (PATERSON et al., 2003).
In summary, there are 56+ potential louse hosts from which no lice have been recorded yet.These are: 11 native breeding host species (5 seabirds, 4 landbirds and 2 marine mammals), 33+ vagrant birds, and 12+ species introduced by human agency (2+ poultry and 10+ alien mammals).They represent 73% of the total potential number of louse hosts for the archipelago, all without any louse record (see Appendix 3).

Discussion
Generally, lice make up a significant portion of the total number of genera and species represented in the invertebrate fauna of oceanic islands, especially of those situated in the Southern Ocean, such as the Subantarctic islands.For example HORNING et al. (1980) recorded 53 species of lice from breeding and vagrant hosts collected in the Snares Islands, representing about a 30% of the estimated total fauna of terrestrial arthropods (D.S. HORNING pers. comm., 2006), while PALMA & HORNING (2002) listed 47 louse species from Macquarie Island vertebrate hosts, representing a 31.5% of a total of 150 species of terrestrial invertebrates (excluding mites) recorded on that island, and MARRIS (2000) reports 40 louse species from Antipodes Island, representing a 23.5% total of the 170 terrestrial invertebrates recorded.
The louse fauna of the Tristan da Cunha archipelago is expected to be proportionally as high among the total native insect fauna as those of other oceanic islands, but a great amount of further collecting is still needed to confirm that statement.Despite the paucity of records, it is already apparent that, among native insects, lice make up a substantial portion of the fauna.HOLDGATE (1965: 366) records 82 species of native pterygote insects for the entire archipelago, excluding parasites.If we add the 13 species of apterygote orders (Thysanura and Collembola), two species of fleas (Siphonaptera) and one louse-fly (Diptera: Hippoboscidae) listed by HOLDGATE (1965: 394, 396), the total would be 98 species, a figure very close to the 100 species estimated by HOLDGATE (1965: 366).Therefore, the known native louse fauna amounts to about a third of the total native insect fauna.
Considering that (1) there are other species of lice known to parasitize the hosts listed in Appendix 2 in other parts of the world (PRICE et al., 2003), which have not been found on Tristan da Cunha hosts yet, and (2) no lice have been recorded from 9 (32%) species of native breeding birds, the total number of louse species would increase considerably after a full ectoparasitic survey of the avifauna has been carried out.That number would be even greater if the remaining 33+ species of vagrant non-breeding birds that visit the archipelago were included in such a survey.The expectation that future collecting efforts are bound to produce additional new louse species records for that island and for the archipelago is further supported by the results of the 2005 collection which, despite the small number of birds sampled and the opportunistic collecting method used, produced three new records for Nightingale Island, and one new record for the entire island group, despite the fact that there have been previous collections made from Nightingale Island (see Appendix 1).Once the total louse fauna of the archipelago is known, it could include over 100 species, that is more than 50% of the total native insect fauna.
The current knowledge gap regarding the invertebrate fauna and its role in the islands' ecosystems is a concern that has in recent years become more prevalent, particularly at Tristan da Cunha, where the introduction of alien species is a problem affecting the livelihoods of its inhabitants as well as posing a threat to the indigenous fauna and flora (WACE & HOLDGATE, 1976).During the last two decades, pest-related problems have become more prevalent with the increase in access and imports to the inhabited Tristan da Cunha Island.Such increase in traffic has also increased the chances of both the introduction of economically important louse species -in particular those which parasitize sheep and cattle -and a re-introduction of human lice with their consequential health risks (RSPB, 2004(RSPB, -2005;;GLASS & SANDERS, 2006).Beitr. Ent. 57 (2007) 1

Conclusions
The importance of invertebrates and their role in ecosystem dynamics have become more and more prevalent, as well as their value as indicators, not only of environmental pattern changes (JONES et al., 2003a), but also of human health and well-being.On a global scale, the terrestrial biodiversity of the islands in the Tristan da Cunha archipelago ranks extremely high in importance, yet the role that the invertebrates play is still poorly understood.
A comprehensive study of the three northern islands' invertebrate fauna is urgently needed, if a sustainable human presence is to be maintained without the risk of loosing native species, including those that may still remain to be discovered.In this regard, parasitic lice are expected to form a substantial component of the total invertebrate fauna.This knowledge gap should be filled sooner than later, as the fauna of the Tristan da Cunha archipelago is depauperate and highly susceptible to changes, either from introductions of alien species or by the extinction of native ones.The single traceable incident is dated March 1998, when the first patient, a young child, was taken to the doctor with nits in her hair.In total, 52 patients were infested, including 5 adults.With no supplies of appropriate medication in stock, a treatment was introduced based on paraffin and vinegar.Affected households were fumigated with insecticides.Patients were isolated until their heads were free of nits.Subsequent monitoring, in particular amongst the school children, was carried out by the doctor and the nursing staff.
The community was kept informed by means of public posters.A talk was given to parents of the school children.Whether the lice were totally eradicated is not clear, but that appears to be the logical conclusion.The source of the headlice is believed to have been a person who visited and stayed on the island for a few months.It is not known where that person originated from, but the principal means of transport to Tristan da Cunha is via vessels coming from South African ports.Since no samples were kept or examined under a microscope, we cannot confirm the identity of the species.However, judging from the above report, we assume that the lice were Pediculus humanus capitis.

Fig. 1 :
Fig. 1: The islands of the Tristan da Cunha archipelago and their position in the Atlantic Ocean.Map drawn by Christine Hänel.
However, besides a study conducted in 1985 on the louse fauna of Gough Island (FURNESS & PALMA, 1992), collections and information about the lice from the other three major islands of the Tristan da Cunha archipelago are still sparse and fragmented.Published records of lice from the Tristan da Cunha archipelago are scattered in several scientific publications dating from 1914 to 2002 (see Appendix 1).

Fig. 2 :
Fig. 2: Photographs of seabird lice from Tristan da Cunha.(A) Harrisoniella hopkinsi: male (left, total length 9.25 mm) & female (right, total length 8.95 mm) found on Tristan albatross.(B) Saemundssonia marina: male (left, total length 1.45 mm) & female (right, total length 1.68 mm) found on white-faced storm petrels.(Photographs taken by Jean-Claude Stahl, MONZ).A   B   Other collections have been made by volunteers as opportunities arose, including that made by R. Cuthbert in 2000-2001; these lice were used to extract DNA for phylogenetic studies carried out at the University of Glasgow and are now deposited in MONZ.The most recent contribution is that of C.H. who collected at Tristan da Cunha and Nightingale Islands in early 2005 during an invertebrate project that formed part of a larger program entitled Empowering the People of Tristan da Cunha to Implement the CBD that was run through the Royal Society for the Protection of da Cunha to Implement the CBD that was run through the Royal Society for the Protection of da Cunha to Implement the CBD Birds [RSPB] (HÄNEL, 2005).
(see details under Collections of Tristan da Cunha lice), and at Nightingale Island during the invertebrate project conducted by C.H. in 2005 (see Appendix 1).
in which, amongst many other lice from elsewhere, he identified specimens from Inaccessible Island as belonging to two louse species (now known as Docophoroides brevis ( about that albatross and its collector, but we have found that the Earl of Crawford (former President of the Royal Astronomical Society) called at Tristan da Cunha precisely on the 17 January 1906 with his yacht Valhalla.However "… Owing to the poor weather he was not able to land, but was met by the governor, Andrea Repetto, with eleven Islanders in two boats .... and the Earl gave the Islanders the mail and stores ..."(FAUSTINI, undated, before  1990).
reviewing the genus Longimenopon THOMPSON, 1948.A specimen collected by Dr. Hagen was later included in the description of a new louse species from Giant petrels, Macronectes giganteus ( Macronectes giganteus ( Macronectes giganteus GMELIN, 1789), by PALMA & PILGRIM, Harrisoniella hopkinsi  EICHLER, 1952and Paraclisis diomedeae.Therefore, the number of louse species recorded from all the islands of the Tristan da Cunha archipelago now amounts to 54 -including one species which is believed to have been eradicated, four straggler or contaminant records, and 6 records which have been identified to generic level only -representing 21 louse genera (see Table1and Beitr.Ent.57 (2007) 1 Appendix 1).One further species needs confirmation because, at present, it is an unidentifiable record (see Colpocephalum furcatum in Appendix 1).

Sphenisciformes (penguins) Eudyptes chrysocome moseleyi Northern rockhopper penguin
Lice recorded from the Tristan da Cunha archipelago.Louse species are grouped alphabetically, first by family, then by genera and species, with their respective hosts and island locations.Hosts and the louse species associated with them in the Tristan da Cunha archipelago.
DOI: 10.21248/contrib.entomol.57.1.105-133Powered by TCPDF (www.tcpdf.org)Tab.2: DOI: 10.21248/contrib.entomol.57.1.105-133Powered by TCPDF (www.tcpdf.org) 4. The lice reported byFURNESS & PALMA (1992: 41)fromPALMA (1992: 41)from PALMA Fregetta grallaria as "Philoceanus sp." have been Philoceanus sp." have been Philoceanus further studied and identified as Philoceanus fasciatus by R.L.P. Philoceanus fasciatus by R.L.P. Philoceanus fasciatus 5.A single male Saemundssonia (Puffinoecus) Puffinoecus) Puffinoecus peusi collected by R. Cuthbert, and a single female peusi collected by R. Cuthbert, and a single female peusi Saemundssonia (Puffinoecus) sp.collected by C. Hänel, both from Puffinoecus) sp.collected by C. Hänel, both from This is most likely a misidentification of Trabeculus schillingi because further records show that this lat-Trabeculus because further records show that this lat-Trabeculus schillingi ter louse is the natural and regular Trabeculus species parasitizing Atlantic petrels.At present, nymphs of Trabeculus species parasitizing Atlantic petrels.At present, nymphs of Trabeculus Trabeculus are unidentifiable without associated adults; therefore, we regard the nymph in question to be Trabeculus are unidentifiable without associated adults; therefore, we regard the nymph in question to be Trabeculus T. schillingi only on the basis of its host association.schillingi only on the basis of its host association.schillingi 7. We are not aware of any published record of human lice from the Tristan da Cunha archipelago.However, from a discussion and follow-up investigations between C.H. and the islanders of Tristan da Cunha in 2005 and 2006, it became evident that at least one outbreak of what appears to have been headlice has occurred amongst the people of Tristan da Cunha during the last decade, and that previous outbreaks may also have occurred in the early 1900s with the arrival of sealers and ship-wrecked castaways.