Pine Hoverfly habitat
Factors affecting selection of oviposition sites by female Pine Hoverflies, Blera fallax
Overview
To assess what factors influence whether female Pine Hoverflies lay eggs into breeding habitat. This will help inform the design and placement of artificial breeding habitat (stumps and troughs) and the provision of more natural breeding habitat (eg through encouraging rot holes).
This project will make use of a long run of data collected by the Rare Invertebrates in the Cairngorms Project and will include field study at reintroduction sites within Strathspey, including the RSPB's Abernethy nature reserve. There may be an opportunity for laboratory experiments too, using captive stock held at RZSS's Highland Wildlife Park.
Contact: Genevieve Tompkins and Annie Ives: rare.invertebrates@rspb.org.uk
Closing date: Ongoing
Timescale: May to June and September to October 2026
Location: Cairngorms, Scotland
Resources available: Data, training and access to RSPB reserves
Key rquirements: Driving licence and own transport essential
Background
The Pine Hoverfly is one of the UK's most threatened species. It’s restricted to the Caledonian pinewoods in the Scottish Highlands, with the remnant population confined to one indigenous site. Conservation efforts to expand its population, made by a long-standing partnership of organisations, are concentrating on supplementation of its breeding habitat using cut stumps and troughs filled with wood chip to mimic pine heart-rot, plus captive breeding and translocation.
A previous PhD study investigated the rates of development of larvae and different types of substrate used within the stumps/troughs (Rotheray EL et al. 2015. Ecological Entomology, DOI: 10.1111/een.12269).
Since 2021, Pine Hoverfly larvae and adults have been released into four sites, including two sites at the RSPB’s Abernethy reserve, and the number of larvae have been monitored annually. The ultimate aim is to establish self-sustaining populations that are not dependent on these interventions and exist within natural rot-holes in mature pines. To get to this point we wish to optimise the surrogate breeding habitat we are providing and this study should help us do this.
Further reading
- Taylor HR, Rotheray E, Elliott A, MacGowan I, Sears J and Tompkins G (2021) Hovering on the edge of extinction: efforts to save the pine hoverfly. British Wildlife. 32: 547–554.
- Taylor HR, Allott C, Tompkins G, The Pine Hoverfly Steering Group, MacGowan I (2025). A large-scale conservation breeding and translocation programme to reintroduce a Critically Endangered saproxylic hoverfly to a Scottish forest ecosystem. Insect Conservation and Diversity. https://resjournals.onlinelibrary.wiley.com/doi/10.1111/icad.70001
Methods and aims:
The proposed project aims to better understand factors that influence whether surrogate breeding habitat is used by gravid female Pine Hoverflies for oviposition.
Factors such as the shape and depth of holes, light levels, humidity and plant chemistry (eg turpines etc) could be investigated in the field from May to June, in relation to the number of larvae recorded in September/October (these data could be made available if the timing doesn't work).
A long run of data on stump and trough condition (eg whether holding water) and numbers of larvae recorded could be utilised. Subject to RZSS approval, there may be scope to study Pine Hoverfly behaviour in the captive-breeding facilities at Highland Wildlife Park.
Learn more about this placement
To learn more about this placement, or to express your interest, please contact Genevieve Tompkins and Annie Ives: rare.invertebrates@rspb.org.uk