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Records of spider parasites in New Zealand Shaun A Thompson Massey University, Manawatu Campus, Centennial Drive, Hokowhitu, Palmerston North 4410 Email: [email protected]

Introduction Spiders frequently fall victim to varying forms of parasitism. For instance, large pompilid wasps will paralyse a spider, drag the spider back to a nest, lay eggs on or inside the spider, and finally the emerging wasp larvae feed on the spider to complete their development (Harris, 1987). It is reasonable to state, therefore, that parasitism plays a considerable role in the ecology of spiders.

New Zealand has a rich and diverse spider fauna with an estimated total of 2000 species (Paquin et al., 2010). With such a high number of spiders, it could be expected that parasites of spiders in New Zealand may also have a rich diversity, although the literature on this topic seems to be scattered and unorganized. In response to this, this report will establish the extent of known spider-parasite interactions in New Zealand and will identify gaps in the scientific literature on this topic.

Methods

To find literature for taxa likely to be spider parasites, in April 2020 I searched Google Scholar with the search string: Spider AND Parasite AND New Zealand - “spider mite”. Specific taxon-related terms such as “Ogcodes” and “Pison” were also included in some searches. The Landcare

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“Fauna of New Zealand” publications were also searched for mentions of spider parasitism. Additionally, some records were opportunistically collected in unrelated searches of the literature.

All forms of parasitic interactions (including kleptoparasitism) were recorded. All species were considered, regardless of whether the parasite and/ or the host are native to New Zealand, but both the parasite and host must exist in New Zealand. All currently accepted binominal names of parasites and host species were used.

Results & Discussion

A total of 12 publications covering 23 parasites and 71 host taxa (identified to genus or species level) were found (Table 1). The most commonly studied group of parasites were species from the hymenopteran family Pompilidae, which accounted for 11 of the 23 parasites. Harris (1987) gives a good account of New Zealand Pompilidae, but I could find no further records describing parasitic interactions involving Pompilidae and spiders after this date.

Broadly, New Zealand’s spider parasites seem to use many hosts and could be considered fairly generalized. Despite this, some parasites were recorded as having only one host species, although in most cases this likely reflects insufficient study of the parasite. Spider size seemed not to govern levels of parasitism: large spiders from groups such as the mygalomorphs (e.g. Porrhothele and Cantuaria) and Lycosoidea (e.g. Dolomedes and Anoteropsis) tended to be common hosts, as did smaller spiders such as Clubiona and Neoramia. Of all recorded parasites, only three were introduced species: the pompilid wasps Cryptocheilus australis and Cryptocheilus bicolor and the theridiid kleptoparasite spider Argyrodes antipodianus. Of these three species, C. bicolor and A. antipodianus have

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been recorded only parasitizing introduced species. Within the native/endemic parasites, most interactions were between native/endemic spiders.

While the role of as spider parasites in New Zealand has received significant attention, the host use and ecology of other groups of parasites remain neglected. For example, species in the Diptera family Acroceridae exclusively parasitize spiders (Schlinger, 1987), and although there are thirteen known species of Acroceridae present in New Zealand (Macfarlane et al., 2010), only one, Ogcodes brunneus, has been investigated to determine what host species are used, and this in a study performed over 80 years ago (Dumbleton, 1940). Similarly, although many species of mite are known to parasitize spiders, I was only able to find a single published account of mites parasitizing spiders in New Zealand (Welbourn & Young, 1988).

The lack of investigations into New Zealand spider parasites may reflect that many of these groups, such as parasitoid Hymnoptera, Acari and smaller Diptera, represent difficult taxonomic groups in terms of obtaining species level identifications. Additionally, although parasites, parasitoids and predators involved in biocontrol of agricultural pests receive considerable investigation, these similar parasitic interactions with spiders possibly have not warranted comparable levels of study, and funding, because they lack the economic relevance of the former. Nevertheless, in terms of fundamental ecological research, parasitism of spiders in general, and specifically by Acroceridae and mites, may be fruitful areas for future study.

Acknowledgements

I would like to thank Dr Simon Hodge for his helpful editing and feedback which greatly improved this report.

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References

Austin AD. (1988) A new genus of baeine wasp (Hymenoptera: Scelionidae) from New Zealand associated with moss. NZ J Zool 15: 173-183 Cummings NJ. (2009) Entomopathogenic fungi in New Zealand native forests: the genera Beauveria and Isaria. [Doctoral thesis]. Canterbury University, NZ. Dumbleton LJ. (1940) Oncodes brunneus Hutton: a dipterous spider parasite. NZ J Sci Technol Sect A: 22: 97-102 Evans HE, Matthews RW. (1973) Behavioural observations on some Australian spider wasps (Hymenoptera: Pompilidae). Trans Royal Entomol Soc London 125: 45-55 Forster RR. (1988) The spiders of New Zealand: Part VI. Family Cyatholipidae. Otago Museum Bulletin 6: 7-34. Forster R, Forster L. (1999) Spiders of New Zealand and their World Wide Kin. Otago, New Zealand: University of Otago Press. Harris AC. (1987) Pompilidae (Insecta: Hymenoptera). Fauna of New Zealand 12. 160 pages. Harris AC. (1994) Sphecidae (Insecta: Hymenoptera). Fauna of New Zealand 32. 112 pages. Laing DJ. (2012) The prey and predation behaviour of the wasp Pison morosum (Hymenoptera: Sphecidae). NZ Entomologist 11: 37-42 Macfarlane RP, Maddison PA, Andrew IG et al. (2010) Phylum Arthropoda Subphylum Hexapoda: Protura, springtails, Diplura, . In DP Gordon (Ed.), New Zealand Inventory of Biodiversity (pp. 233-467). Canterbury University Press. Paquin P, Vink C, Dupérré N. (2010) Spiders of New Zealand: annotated family key & species list. Manaaki Whenua Press, Lincoln, New Zealand, 118 pp. Poinar GO. (1985) Mermithid (Nematoda) Parasites of Spiders and Harvestmen. J Arachnology 13: 121-128 Poinar GO, Early JW. (1990) Aranimermis giganteus n. sp. (Mermithidae: Nematoda), a parasite of New Zealand mygalomorph spiders (Araneae: Arachnida). Revue Nématol 13: 403-410 Pollard SD. (1982) Epipompilis insularis (Hymenoptera: Pompilidae), a parasitoid of hunting spiders. NZ J Zool 9: 37-39 Schlinger EI. (1987) The Biology of Acroceridae (Diptera): True Endoparasitoids of Spiders. In: Nentwig W. (Ed) Ecophysiology of Spiders. Springer, Berlin, Heidelberg. Welbourn WC, Young OP. (1988) Mites parasitic on spiders, with a description of a new species of Eutrombidium (Acari, Eutrombidiidae). J Arachnology 16: 373-385

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