Stick insect on my doorstep...

...10 cm long. Didn't even know they exist here. Based in South Kerry and according to this there are colonies in Kerry and Cork, brought in in trees imported into Dereen Gardens on the Kenmare Bay...

http://www.irishtimes.com/news/oh-to-be-a-stick-insect-1.342399

Anyway, as the article suggests, reported it to the UK Phasmid Study Group.

A very random Christmas Eve vistor!

Got this back from them...

Very many thanks for this stick-insect sighting, and images, from south west Ireland. I collate all records of the naturalised stick-insects and attach two recent papers giving more information on these intriguing insects. The 2006 one concentrates more on distribution, but has specific information regarding Ireland on page 3, and the Atropos article is a more general one covering life cycles etc.

I have received more than a dozen reports from Ireland through the online reporting system. The species present around the Bay of Kenmare (and the brown adult in your images) is the Unarmed Stick-insect Acanthoxyla inermis, a species originally from New Zealand. The first stick-insect record from Ireland was in 1956 from Rossdohan Island, about 13 miles SW from Kenmare, but they were probably there much earlier. They arrived on plants imported from their native land for the ornamental gardens on the island, which were first laid out in Victorian times. The Truro nursery firm of Treseders were the sole suppliers of NZ plants at this time, through their subsidiary nursery in Australia, and were closely linked to the earliest reports of Unarmed Stick-insects here in the UK. Treseders supplied plants to Rossdohan Island, and to Viscount Mersey’s estate on the opposite bank of the Kenmare River, at Derreen, where these stick-insects are also present in the gardens.

These stick-insects can be either brown or green, with green being the more common. All the ones you see are female, laying fertile eggs without the need for a male; a process known as parthenogenesis. They have an annual life cycle, hatching from the eggs in spring and grow quickly to become adult by summer. Adults have a body length of about 10 cm/4 inches (15 cm/6 inches when you add in the front and rear legs) and are the longest UK insect. Adults do not live very long, with few surviving much into winter. In their brief adult lives they can lay several hundred eggs, which just drop below the bush the insect was feeding on, to start the life cycle again the following spring. A very small number might overwinter in sheltered areas but this is not important for the survival of the species. It is the eggs laid in summer and autumn which carry the species through the winter, to hatch out the following spring and start the cycle all over again.

As the temperature is dropping and the leaves are losing their nutrients, these stick-insects will move off the plants in search of food and warmth. This is when they are most often found on south or west facing surfaces trying to get any available sunshine.

They can move surprisingly quickly in short bursts if they need to, but their natural defence is to move as little as possible, so they will be overlooked by predators as just another part of the plant.

This is my map of stick-insect locations around Kenmare. Apart from Rossdohan Island and Derreen Gardens, I have several confirmed reports north of Kenmare Bay including nearby Rossdohan, Derryquin and Sneem, as well as Blackwater Bridge, Cappanacush East, Claddananure and Lissyclearig. A further location south of Kenmare Bay was at Coolgreen, Glanmore Lake, a few miles south of Derreen Gardens.

Kenmare Bay Locations

There are unconfirmed reports from Bere/Bear Island and Waterville. In 2001 there was an unconfirmed report of the Unarmed Stick-insect well away from Kenmare, at Ballincollig a mile west of Cork. I am pleased to say this was confirmed in 2014 with a clear picture from a garden in Cork itself.

I understand that when Rossdohan Island was abandoned in the 1920s, following a large fire, many of their ornamental plants were removed and found themselves in local gardens. This no doubt explains the current distribution of the stick-insects on the north of the bay, as they hitched a ride on those plants, exactly as they did in their original translocation from New Zealand. These stick-insects have neither need nor ability to travel far under their own steam, so all colonies are very localised. Their main means of distribution is with human help as we bring plants into our garden from areas where stick-insects are present.

denbatt

My wife's father found one in his garden in Castletownbere the other day.