SNH Invertebrate Site Condition Monitoring of Beetle Assemblage Features 2015: Rhidorroch Woods SSSI

Quality Control

We have a very high level of confidence in this dataset. The recorder and/or determiner is a highly experienced ecologist. Where necessary, rare specimens were compared against reference collections, those held in the National Museums Scotland collection and identities confirmed with experts.

Method steps

1. Surveys targeted the beetle assemblage feature of Rhidorroch Woods SSSI and involved a combination of pitfall trapping, beating, sweeping and bugvac sampling. Birch woodland was targeted as this is the only tree species in Rhidorroch Woods which Microrhagus pygmaeus is known to use for larval development. Surveys were concentrated on habitats with which M. pygmaeus is associated; this included sweeping bracken in close proximity to deciduous deadwood. A single transect of five pitfall traps (set 2 m apart) was installed on 29/06/2015 (at NH2371293728). Each pitfall trap consisted of a plastic cup dug into the ground so that the lip was flush with the substrate surface. Chicken-wire was attached to cover traps in order to exclude small vertebrates. A mixture of 70% propylene glycol antifreeze and 30% water was added to a depth of 2.5 cm in each trap, and a drop of washing-up liquid was added to break surface tension. Traps were left in situ until 16/07/2015 when they were collected and removed. Beating was undertaken at a single location (NH2371893797) on 29/06/2015 and a second location (NH2394193033) on 16/07/2015. This involved the use of a large, soft paint brush to dislodge invertebrates from bark into a tray held underneath. Trees or bushes were then gently beaten so as to dislodge further invertebrates into a white sheet at the base of the tree. Sweep netting was undertaken on 29/06/2015. Vegetation within three 10 m2 areas (NH2371893797, NH2373193762 and NH2373193785) was swept with a robust net, sampling a variety of micro-habitats. Bugvac sampling was undertaken at three locations (NH2371493738, NH2373393750 and NH2394193033) on 16/07/2015. This involved the use of a a^??bugvaca^??, which is a modified leaf blower (Husqvarna 125BVX), to vacuum sample invertebrates from ground level. Each sample involved pressing the bugvac nozzle to the ground for 10 seconds at five points. Specimens were then emptied from the net into a white plastic tray and collected with forceps for subsequent identification.

Rhidorroch Woods SSSI