Investigating the feeding preferences of adult leuctra inermis, for the pollen of typical riparian tree species

Some Plecopteran species feed on tree pollen as adults (e.g Chloroperlidae); if particular pollen species are preferred the presence of these species may influence the breeding success of some stoneflies and consequently how riparian vegetation is managed. It was hypothesised that the stonefly (Leuctra inermis) would show a preference for pollen of birch and willow over the pollen of spruce trees. Stonefly nymphs were captured and reared until emergence in the laboratory before being exposed to pollens of differing trees species in a choice/no choice feeding preference experiment. The indi-viduals captured demonstrated a significant preference for the pollen of birch (Betula pendula) trees over spruce (Picea sitchensis). The factors driving the observed preference are difficult to determine but may relate to the protein content of the pollen grains.