Invertebrata

The Prince Edward Islands only have two terrestrial vertebrates - the lesser sheathbill and the house mouse (introduced by man) - but there are a surprising number of terrestrial invertebrates. Most of these have become so specially adapted to the cold, windy climate that they are hard to recognise at first. For example the Marion flightless moth (Pringleophaga marioni) is closely related to clothes moths but looks more like a cockroach because of its reduced wings.
The invertebrate community on the islands is essential for recycling nutrients, keeping plants fertilized and breaking down dead matter. The introduction of alien species that threaten these communities is thus potentially disastrous for the island ecosystem as a whole. A distinction is drawn between indigenous, alien and vagrant species, as humans have introduced many invertebrates to the islands in the past, and new species occasionally get blown in from other continents.





Insects

Indigenous Species

Beetles:
Weevils (Bothrometopus elongatus, Bothrometopus parvulus, Bothrometopus randi, Ectemnorhinus marioni, Ectemnorhinus similis, Palirhoeus eatoni), Rove beetle (Halmaeusa atriceps), Hydraenid beetles (Meropathus chuni)
Flies:
Large flightless kelp-fly (Paractora dreuxi mirabilis), Small flightless kelp-fly (Apetaenus litoralis), Small kelp-fly (Listriomastax litorea), Fungus gnat (Lycoriela aubertii), Flightless midge (Telmatogeton amphibius)
Moths:
Marion flightless moth (Pringleophaga marioni), Flightless moth (Pringleophaga kerguelensis), Tussock grass moth (Embryonopsis halticella)
Wasp:
Parasitic wasp (Kleidotoma icarus)
Psocid:
Antarctopsocus jeanneli

Naturalized Aliens

Thrips:
Apterothrips apteris
Flies:
Blow-fly (Calliphora vicina), Lesser house fly (Fannia canicularis), Vinegar fly (Scaptomyza sp.), Moth fly (Psychoda parthenogenetica), Midge (Limnophyes minimus)
Moths:
Diamond-backed moth (Plutella xylostella), Noctuid moth (Agrostis ipsilon)
Butterfly:
Painted lady (Vanessa cardui)
Aphids:
Potato aphid (Macrosiphum euphobiae), Aphid (Myzus ascalonicus), Oat aphid (Rhopalosiphum padi)
Collembola (Springtails)



Vagrants

Beetles:
Shot hole borer (Anobiidae sp.and Dermestidae sp.)
Bugs:
Shield-backed bug (Cryptacrus comes)
Flies:
Lamprolonchaea smaragdi and Anthomyiidae sp.
Moths:
Noctuid moth (Chrysodexis acuta), Noctuid moth (Cosmophila sabulifera), Noctuid moth (Spodoptera exigua), Cutworm (Agrostis segetum), Moth (Nomophila sp.), Cereal moth (Trichoplusia orichalcea), American bollworm (Helicoverpa armigera)
Ants:
Lepisiota capensis
Roaches:
German cockroach (Blatella germanica)

Other Invertebrates

Spiders:

Four species are found, two of which are small and black, with the other two being larger, more hairy and patterned (Myro kerguelensis and Myro paucispinosus).

Mites:

Sixty species have been recorded, with representatives in the following orders:Prostigmatidae, Astigmatidae, Mesostigmatidae and Bdellidae.

Collembola:

A recent investigation (1996 - 2000) by the Marion Island Terrestrial Invertebrate Ecology (MITIE) program has concluded a total of sixteen Collembolan (Springtail) species present.

Slugs and snails:

The only terrestrial snail is the indigenous Notodiscus hookeri. The slug Deroceras caruanae is an introduced species.

Earthworms and roundworms:

These are very common but the species are poorly known. The largest is thought to be Microscolex kerguelarum, and there are also representatives from the family Enchytraeidae.

Isopods:

The isopod on the photograph was found on Boulders Beach