Assessment of the biocontrol potential of natural enemies against psyllid populations in a pear tree orchard during spring

BACKGROUND: Modern pest control management systems are based on the support of naturally occurring arthropod predators, as it has been shown that such predators offer an important ecosystem service. However, most naturally occurring arthropod predators are generalists (euryphagous). Their role in the biological control of specific pests has been recognized but remains poorly studied. Here, we focused on the naturally occurring arthropod predators of psyllids - the main insect pest of pear trees. We investigated the abundance of psyllids and all of their potential enemies in an abandoned pear orchard on a weekly basis from early spring to early summer. In addition, employing polymerase chain reaction diagnostics and specific primers, we investigated the predation rate on psyllids in all predators collected. RESULTS: We found four predatory groups: spiders were the most abundant (60%, N = 756), followed by coccinellid beetles, anthocorid bugs and cantharid beetles. Anthocorids and spiders had the highest predation rates among the predatory groups. Among spiders, >50% of foliage-dwelling spiders (belonging to the genera Philodromus and Clubiona; N = 206) were positive for psyllids and showed a numerical response to the abundance of psyllids. CONCLUSION: We conclude that foliage-dwelling spiders are, of the four groups, the most important natural enemies of psyllids on pear trees during spring in Central Europe, as they outnumber specialized Anthocoris bugs. (c) 2021 Society of Chemical Industry

Automated summary

Through our investigation, we found four predatory groups in an abandoned pear orchard: spiders were the most abundant, followed by coccinellid beetles, anthocorid bugs, and cantharid beetles. Among these groups, anthocorid bugs and spiders had the highest predation rates. Foliage-dwelling spiders, especially those belonging to the genera Philodromus and Clubiona, were identified as the most important natural enemies of psyllids on pear trees during spring in Central Europe, outnumbering specialized Anthocoris bugs.