To celebrate National Insect Week, Rare Invertebrates in the Cairngorms Project Officer Genevieve Tompkins shares a bit about some of the other special invertebrates the team comes across.

Even more Rare Invertebrates in the Cairngorms

The Rare Invertebrates in the Cairngorms partnership project is a quest, led by volunteers, to find six of the rarest invertebrates across the Cairngorms. These insects really are rare, it’s been seven years since an adult pine hoverfly was last seen in the wild here, so motivation to keep looking is key. Luckily for us, these invertebrates live in a unique and beautiful landscape and, while exploring these special places to look for them, other scarce treasures are revealed. 

Caledonian pine forests are home to the pine hoverfly, one of our target species, with rotting holes in dead trees a vital resource for this extremely rare fly. Despite deadwood invertebrates making up 20% of the entire British fauna, deadwood has only in recent decades begun to receive the attention it deserves as an invertebrate super-habitat. Warm June days find us searching the forests for the adult hoverflies, enveloped in the delicious smell of hot pine. These places teem with insect life. Across our path runs the nationally scarce longhorn beetle, Judolia sexmaculata, while on a log sits the ribbed pine borer beetle, Rhagium inquisitor, both of who’s young develop under the bark of fallen and standing dead pine trees. A cursory glance over the pile of logs further rewards us with the colourful appearance of an ant beetle, Thanasimus formicarius, on patrol for its deadwood beetle prey. Then a velvet blue flash alerts us to the presence of a blue rove beetle, Ocypus ophthalmicus, who raises its abdomen in fierce defence, like a scorpion, as we look at it. This Nationally Scarce beetle is making use of the sandy soil and low vegetation found on forest edges and in recently felled plantations.

black and white striped beetle on dirt ground

Judolia sexmaculata, Credit: Genevieve Tompkins.

Combing the forest for flowering rowan, a favourite food plant for the pine hoverfly, leads to further discoveries. There is excitement with the unexpected arrival of an aspen hoverfly, an endangered species and another deadwood specialist, this time relying on decaying aspen trees. And, after a few more minutes searching, we are suddenly dazzled by an emerald jewel, the northern rose chafer, Protaetia metallica, placidly feeding on a rowan spray. This is a real rarity outside the Spey valley and yet another species which relies on decaying wood, the young beetles feeding on it within wood ants nests.

iridescent green brown beetle on white flower

Northern rose chafer, Credit: Genevieve Tompkins.

Wood ants host another of our target species, the shining guest ant. Patience is required to survey for this miniscule insect, with many hours spent staring at the nests. However, time spent on this has paid off for species champions Ross and ‘Antboy’ Xander Johnston, who in the process have also discovered new locations for the endangered narrow-headed ant and exciting potential evidence for the very rare silky gallows spider.