Aerial psyllid (Hemiptera: Psylloidea) detection and monitoring using suction traps in Britain: population observations, new species found and a revised British checklist

The Psylloidea contains species that can transmit pathogens to plants, including important agricultural crops e.g. the proteobacterium ‘Candidatus Liberibacter solanacearum’ (CaLsol) to potatoes. To obtain a better understanding of British psyllid populations, a study was conducted over two years to determine their aerial incidence and diversity using an existing network of 12.2 m suction traps. In total, 42 species were detected in the traps. In 2015 in England, the most common species was the grouping of Cacopsylla melanoneura and C. affinis followed by Trioza remota (the latter being most prevalent in autumn). In contrast, in Scotland Cacopsylla species (melanoneura, affinis, pulchra and brunneipennis) accounted for 81% of the population in spring and summer. The yearly sampling in England in 2015 revealed that the aerial movement of the most common species differed in their phenology. The grouping of Cacopsylla melanoneura and C. affinis, as well as T. urticae were most common in summer whereas T. remota was most prevalent in late autumn. Three species new to Britain: Cacopsylla alaterni, Trioza anthrisci and Ctenarytaina spatulata were caught during sampling, in addition to Trioza apicalis which transmits CaLsol. Following our study, the British psyllid checklist was revised and is presented here. The potential of suction traps for monitoring and detecting psyllid species was demonstrated in Britain and confirmed by a limited assessment of catches from a Swedish trap in which two species not present in Britain were found. These were Trioza tatrensis and Trioza dispar.