The assessment of arboreal insect fauna: comparisons of knockdown sampling and faunal lists

Abstract. 1. A comparison is made between the fauna of six British tree species sampled by pyrethrum knockdown and the faunal lists in the literature for the same tree species.
2. Conspecific trees vary both in abundance of arthropods and their proportional distribution across taxa, but there are important overriding differences between tree species.
3. The percentage similarity in faunal composition between tree species reflects the ecological specificity of the arthropod groups used for the comparison.
4. The similarity in species composition between tree species is least for phytophages, the guild most closely associated with particular tree species, The two species of Salix are most similar in their fauna for most guilds.
5. About 40% of the entirely phytophagous species in the faunal lists for native trees were found in the knockdown samples.
6. The proportion of individuals of predominantly phytophagous taxa collected that belong to the relevant faunal lists ranges from 0.39 to 0.99.
7. Those species found in the knockdown samples which are not included in faunal lists none the less contribute to the trophic web of the tree.
8. The relative species richness of arboreal faunas assessed from knockdown samples parallels that derived from faunal lists.
9. The two approaches to the categorization of arboreal faunas, knockdown sampling and faunal lists, provide comparable data.     

Analysis of zigzagging flight in moths: a correction

In 1978 we reported the results of an analysis of the zigzagging behaviour of male Plodia interpunctella flying up a plume of sex pheromone (Marsh et al. , 1978). Since then we have discovered that, owing to two technical faults, we used an incorrect time base in analysing the videotape records of the moths' tracks. The original tapes have now been re-analysed and a full revision paper is being prepared which shows that only one important conclusion must be changed. Meanwhile that incorrect conclusion has been cited at least twice (Schöne, 1980, p.236; Murlis & Jones, 1981) so we here summarize the correction to be made.     

Characterization of microsatellite loci in the endemic mound spring snail Fonscochlea accepta and cross species amplification in four other hydrobiid snails

We identified and characterized nine microsatellite primer pairs from Fonscochlea accepta, a species of hydrobiid snail endemic to artesian mound springs associated with the Great Artesian Basin in arid South Australia. The loci were highly polymorphic, with five to 30 alleles per locus. Gene diversity, estimated as expected heterozygosity ranged from 0.364 to 0.851, and was generally matched by levels of observed heterozygosity (0.373–0.829). Cross‐species amplification trials with four other hydrobiid species associated with these southern mound springs showed that these primers will be useful for genetic analyses of these other endemic snails.