Primeiro registro e flutuação populacional de Aphis ruborum (Hemiptera: Aphididae) em amoreira-preta, em ambiente protegido

Abstract

The cultivation of blackberry (Rubus spp.) is an alternative for small rural properties, traditionally grown without plastic covering, with restricted occurrence of pests. However, in a protected environment, some microclimatic conditions are altered, such as temperature, insolation, relative humidity, and the absence of precipitation. These changes may influence the presence of pest insects, such as sucking insects and natural enemies. This work, conducted in three studies, aimed to identify and study the fluctuating populations of aphids and natural enemies in blackberry varieties in a protected environment. The studies were conducted in the first and second vegetative and productive cycles of four varieties (BRS Tupy, BRS Xavante, BRS Xingu and BRS Cainguá), in a greenhouse located in the College of Agronomy and Veterinary Medicine (FAMV) of the University of Passo Fundo (UPF) (28º15'46''S, longitude 52º24'24''W), in Passo Fundo, state of Rio Grande do Sul, Brazil. In the first study, we identified the presence of an aphid species not yet reported in the blackberry crop in Brazil, identified according to morphological characteristics and by phylogeny of the cytochrome oxidase gene (COI). The second study evaluated the population fluctuation of aphids and natural enemies in the period from September 2020 to December 2021, using Moericke traps. The third study evaluated the population fluctuation of A. ruborum and natural enemies on the leaves of the four varieties, in two harvests (2020 and 2021). The aphids isolated from the samples were identified as Aphis ruborum, popularly known as the mulberry aphid. This is the first record of A. ruborum occurrence in blackberry in Brazil. The natural enemies collected in Moericke traps were three species of coccinellids, two sirfids and six parasitoids. The population fluctuations determined in the Moericke traps show that, even as a recently discovered pest in Brazil, the natural enemies of other aphids have the ability to regulate the population of this new aphid. The occurrence of A. ruborum throughout the cycle, and more than one infestation peak may occur, at the beginning of budbreak and flowering, and during the fruit ripening phase. BRS Tupy and BRS Xingu are more susceptible to the occurrence of A. ruborum. It is concluded, therefore, that in protected cultivation the presence of aphids occurs, as well as natural enemies, whose monitoring is necessary to determine the need for control intervention.