Northern Ireland, invertebrate finds in review 2023

Friday 29th December 2023

…a blog written by Joshua Clarke, Buglife Northern Ireland Conservation Officer.

During 2023, there were several invertebrate finds of interest in Northern Ireland by our Conservation Officer Joshua Clarke. These were found during our surveys of coastal habitats, funded by the DAERA Environment Fund.

Spot-winged Spring Beegrabber (Myopa tessellatipennis) © Joshua Clarke
Spot-winged Spring Beegrabber (Myopa tessellatipennis) © Joshua Clarke

First up, is a Conopid fly, the ‘Spot-winged Spring Beegrabber’ (Myopa tessellatipennis) found in April 2023, Co. Down. Conopidae is a family of flies recognisable in the field by their often stout build with broad head and posture where the abdomen partially curves under. All species of Conopidae are internal parasites of bees and wasps; sometimes known as ‘beegrabbers’ due to how the female intercepts their host in flight and oviposits her eggs between segments of the host’s abdomen.

With a recent Irish dataset update, we can see species within the Conopidae family like Sicus ferrugineus and Conops quadrifasciatus are commonly encountered. With a few exceptions, the genus Myopa is seldom recorded which could be for several reasons, including difficulties in identification. Prior to the 2023 record in Co. Down, M. tessellatipennis was last recorded in Ireland in Dublin, 1937.

Sandpit Mining Bee (Andrena barbilabris) © Joshua Clarke
Sandpit Mining Bee (Andrena barbilabris) © Joshua Clarke

The life history of M. tessellatipennis is still largely unknown, i.e., for example, we don’t know what species is the host , though several notes have considered the Sandpit Mining Bee (Andrena barbilabris) to be a host.  Though no interceptions were observed, the specimen was found amid an A. barbilabris mating aggregation which would suggest a possible link, coupled with activity period in spring – but this is not confirmed.

Next, we have the Noble Tortoise Beetle (Cassida nobilis), found in June 2023. Tortoise Beetles are members of the leaf beetle family, Chrysomelidae. Leaf beetles are often associated with a host plant for all of their life stages; e.g., see our work with Lough Erne Landscape Partnership on the endangered Zircon Reed Beetle (Donacia aquatica).

There are around eight tortoise beetle on the Irish checklist and they can look odd with a flattened downward-facing head; their larva are also interesting with some species forming intriguing shields made of sheds of exoskeleton and frass (debris or excrement particularly produced by boring insects.

Noble Tortoise Beetle (Cassida nobilis) © Joshua Clarke
Noble Tortoise Beetle (Cassida nobilis) © Joshua Clarke

Noble Tortoise Beetles are associated with vegetation on the upper strandline or sandy/chalky soil, with salt tolerant species of plant, like oraches. In Britain, Noble Tortoise Beetles are considered scarce (Notable B), with the status across Ireland being localised in southern Co. Down. The record discovered during our surveys was found in suitable habitat at Ballyquintin Point ASSI, which forms the southern tip of the Ards peninsula. As no records were found via the relevant databases, this appears to be a new site for them.

Bees are always a favourite, and some notable finds occurred during this survey season during June. With a quick step away from the coastal habitat, the Flat-ridged Nomad Bee (Nomada obtusifrons) was found locally in Belfast near to its host, Small-flecked Mining Bee (Andrena coitana). The Flat-ridged Nomad Bee is listed as ‘Endangered’ on the Regional Red List of Irish Bees, and in our own Northern Ireland Threatened Bees Report.

Flat-ridged Nomad Bee (Nomada obtusifrons) © Joshua Clarke
Flat-ridged Nomad Bee (Nomada obtusifrons) © Joshua Clarke

Back to coastal habitats, again along the Co. Down coast, our surveys led to an interesting find of the Blunt-jawed Nomad Bee (Nomada striata). This species is a kleptoparasite (a form of feeding in which one animal deliberately takes food from another – in this case, the Nomad oviposits an egg in a provisioned nest of host, both resources and host larva consumed by the Nomad larva) of Wilke’s Mining Bee (Andrena wilkella). Prior to a single record in 2017, this species had not been recorded in Northern Ireland since 1919 – this coastal site is new to known distribution in Northern Ireland. This species will require further monitoring in the new year.

Finally; a personal favourite group for our Conservation Officer to share are the Opiliones, an arachnid order commonly called harvestmen that often goes under-the-radar. The Irish Checklist of Opiliones lists 19 species present across Ireland, though with establishing non-natives, this may need updating. With additional support from the Irish Naturalist Journal, new interest in them was achieved. #OurOpiliones

Blunt-jawed Nomad Bee (Nomada striata) © Joshua Clarke
Blunt-jawed Nomad Bee (Nomada striata) © Joshua Clarke

One particularly important find for Northern Ireland (more records in the south, but not many), was recording our rarest harvestman and third record of the native Anelasmocephalus cambridgei (Fig. 6) at a new site in Co. Down. Previously this species had been found at a bog in Co. Armagh, and in the middle of a road on Rathlin Island.

A. cambridgei is different in appearance to a typical harvestman, with a flattened body – it is also the only member of the family Trogulidae in Ireland, with an interesting life history too. Eggs are laid in empty snail shells, and the newly hatched harvestmen are purple in colour. As the young harvestmen go through moults, they lose the purple colour but gain their characteristic soil-covered appearance (they stick soil to their bodies). A. cambridgei are also a specialist snail eater (but not obligate), and so molluscicides (i.e slug/snail pellets) have the potential to cause issues for them.

Anelasmocephalus cambridgei © Joshua Clarke
Anelasmocephalus cambridgei © Joshua Clarke

For the 2024 survey season, we are hoping for volunteers to help monitor species and habitat. We will be developing species transects for the Noble Tortoise Beetle and coastal jumping spiders, alongside more specialist surveys for our most threatened species. There will also be a chance to support habitat restoration work too!

Please email Joshua Clarke ([email protected]) if would like to be put on a mailing list to find out more.