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

Abstract

The pear psyllids (Cacopsylla Ossiannilsson; Hemiptera: Psylloidea: Psyllidae) are a taxonomically difficult group of at least 24 species native to the Palaearctic region. One or more species occur in most pear-growing regions, in some cases as invasive introductions. Existing reviews of this group are primarily of taxonomic focus with limited overviews of biology. The earliest biological studies of the pear psyllids centered on a core group of a few western European species. In part, this focus arose because diversity of the pear psyllids was poorly understood. As taxonomic understanding has advanced over the last 3 decades, research has expanded taxonomically. Increasing difficulties in controlling the pear psyllids additionally has contributed to growth in research. Here, we review a now-extensive literature on diversity, biology, and management of the pear psyllids. Three broad observations emerged from this synthesis. First, large gaps in biological understanding of the pear psyllids persist for several geographic faunas, most notably for psyllids of the Eastern Palaearctic region. Second, taxonomic diversity is accompanied by biological diversity. Despite the commonality in host use among the pear psyllids, with each species being limited to development on Pyrus, striking differences exist among species in life cycles, wintering, and other biological traits. Third, many of the tools being used to manage pear psyllids today are in existence because of the long history of basic research which has targeted these pests. These tools include new insecticides of higher selectivity, various cultural and horticultural tactics, and practices that conserve natural enemies in orchards.

Evaluation of a push-and-pull strategy using volatiles of host and non-host plants for the management of pear psyllids in organic farming

“…The solutions were made by continuously stirring the mixture overnight at 1500 rpm at room temperature to have a homogenous solution. Two formulations were performed ( Civolani et al., 2023 ): for the attractive mixture (Mx1), the amount of the synthetic mixture in the solutions was 0.1, 1, and 5% (v/v) ( Seemüller et al., 2011 ); Repellent EOs, CWO, and CBO were formulated with 10% (v/v).…”

“…Behavioral assays were carried out to determine the responses of ( Civolani et al., 2023 ) wild adult female pear psyllids, C. pyri , to synthetic blends and single compounds of pear volatiles (attractive compounds). The reaction of Mx1 on C. pyrisuga was also evaluated.…”

“…The pear psyllids (Hemiptera: Psylloidea: Cacopsylla ) comprise 24 known species of small sap-feeding insects limited in developmental hosts to pear (Rosaceae: Pyrus ) ( Civolani et al., 2023 ). Several of these species are important pests of commercial pear, most notably Cacopsylla pyri (L.) and Cacopsylla pyricola (Förster) , in Europe and North America.…”

“…Pear decline is one of the most devastating diseases on Pyrus communis in Europe and North America ( Seemüller et al., 2011 ). Along with codling moth [Lepidoptera: Tortricidae: Cydia pomonella (L.)], the pear psyllids are the most damaging arthropod pests in commercial pear orchards worldwide ( Civolani et al., 2023 ). Successful phytoplasma transmission experiments with C. pyricola (Foerster, 1848) as vectoring species have been carried out in North America ( Jensen et al., 1964 ) and the UK ( Davies et al., 1992 ).…”

“…In addition, C. pyrisuga (Foerster, 1848) has been found to carry the phytoplasma, and successful transmission has been recently reported ( Riedle-Bauer et al., 2022 ). C. pyri and C. pyricola are polyvoltine [2–8 and 3–5 generations per year, respectively ( Civolani et al., 2023 )] and can be found on pear trees all year round. In contrast, C. pyrisuga is a univoltine migratory species.…”