Diversity, biology, and management of the pear psyllids: a global look

Authors: CIVOLANI, STEFANO - University Of Ferrara; SOROKER, VICTORIA - Volcani Center (ARO); Cooper, William - Rodney; Horton, David

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2023
Publication Date: 9/23/2023
Citation: Civolani, S., Soroker, V., Cooper, W.R., Horton, D.R. 2023. Diversity, biology, and management of the pear psyllids: a global look. Annals of the Entomological Society of America. https://doi.org/10.1093/aesa/saad025.
DOI: https://doi.org/10.1093/aesa/saad025

Interpretive Summary: The pear psyllids consist of 24 species native to Europe and Asia. These sap-feeding insects are among the most damaging pests of commercial pear orchards in Europe, Asia, and as introductions in the Americas. Recent advances in understanding the true diversity and geography of these pests has been accompanied by a surge in new biological information, which has yet to be evaluated and compared among species. We evaluate and compare geography, biology, and pest management approaches for this complex of pest species. Our primary conclusion is that the pear psyllids, all of which are limited to development on the same host plant taxon (pear), nonetheless exhibit extensive differences among species in biology, most notably in life cycles, wintering strategies, and life history traits such as fecundity or development rates. We also show that the surge in basic biological research has been important in that it has made it easier to replace or partially replace insecticidal controls for these pests with less chemically intensive approaches, such as the use of biological control and certain horticultural practices.

Technical Abstract: The pear psyllids (Cacopsylla spp.) form a taxonomically difficult complex of 24 species native to the Palearctic region. One or more species occur in most pear-growing regions worldwide. Pear psyllids are among the most damaging and difficult-to-control pests of commercial pear orchards. Existing reviews of this group are primarily of taxonomic focus or are limited to individual species. Biological research until recently focused extensively on a core group of a few western European species, largely because diversity of the pear psyllids was only incompletely understood. Improved taxonomic understanding of the pear psyllids over the last 2-3 decades has been accompanied by a global surge in research. Increasing difficulty in controlling these pests additionally has contributed to this research surge. We review a now-extensive literature on diversity, geography, biology, and management of the pear psyllids. Two broad observations emerged from this synthesis. The first observation is that taxonomic diversity within this group is accompanied by extensive biological diversity. Despite the commonality in host use among pear psyllids – with each species being limited to development on Pyrus – striking differences exist among species in traits such as life cycle, diapause, overwintering stage, or other biological attributes. Second, this review describes how psyllid control practices are shifting in pear orchards as broadly-toxic insecticides are replaced by less toxic chemicals combined with new cultural practices and biological control. Basic biological research is shown to be an important resource in implementing these new control tactics.