Features and dynamics of species composition of entomoacarosystems in plum orchards

Abstract

The long-term analysis of the entomocomplex of plum orchards, carried out in Krasnodar Territory, revealed variations in the quantitative composition of entomofauna of harmful species and the level of their harmfulness. It was established that, in the period from 2005 to 2021, the rotation of dominant and secondary species occurred. The main species included plum Grapholitha funebrana Treitschke and oriental Grapholitha molesta Busck fruit moths, plum black Haploca minuta Christ. and yellow Hoplocampa flava L. sawflies, plum aphid Hyalopterus pruni Geoffr. and twospotted spider mite Tetranychus urticae Koch. Associated species included plum gall Acalitus phloeocoptes (Nal.) and hawthorn Tetranuchus viennensis Zacher. mites, fruit-tree Tibicina haematodes Scopoli and citrus flatid Metcalfa pruinosa (Say) planthoppers and leaf roller moths of Tortricidae family. The group characterised by a limited distribution area includes the Californian Quadraspidiotus perniciosus Comst. and Turanian Diaspidiotus prunorum Laing. scales, plum Sphaerolecanium prunastri Fonsc and European brown Parthenolecanium corni Bouche. scales, seed wasps Eurytoma amygdali End., brown marmorated stinkbug Halyomorpha halys (Stål) and secondary insects (unequal bark beetle Xyleborus dispar F., fruit tree bark beetle Scolytus rugulosus (P.W.J. Müller), wood leopard moth Zeuzera pyrina L). When considering the structure formation of phytophage complex according to phylogenetic specialization, taking into account trophic relationships, it was established that the proportion of polyphages is 2.5 times higher than that of oligophages and 8.5 times higher than that of monophages from the total number of registered pest species. In the past decade, a reduction of pesticide load in plum agrocenoses has been observed due to the wider use of agrotechnical methods and the inclusion of bioregulatory and biological insecticides into protection systems, which contributed to the preservation and increase of beneficial fauna. Entomophages constitute 7–10% of the total number of entomoacrocenosis dominated by Hymenoptera and Coleoptera classes and mites of Acari subclass. The long-term monitoring of species composition, rotation of dominant and secondary pest species and entomophages, variations in their number and harmfulness, seasonal dynamics, trophic relationships of plum entomoacrocenosis under varying environmental conditions and increasing intensification of agricultural production expand the possibility of phytosanitary optimisation strategy of perennial agrocenoses in the south of Russia. This contributes to the preservation of regional biodiversity, as well as to the stable production of high-quality ecologically safe products with minimal negative impact on the environment.