Mite fauna (Acari) associated with apple orchards (Malus domestica) and spontaneous vegetation as reservoir for predatory mites / Acarofauna (Acari) associada a pomares de maçã (Malus domestica) e vegetação espontânea como reservatório de ácaros predadores

Abstract The aim of this study was to recognize the mite fauna associated with apple orchards in southern Brazil and present a dichotomous key of the species sampled and those already reported in apple trees in southern Brazil. The studies were carried out in the 2020/2021 harvest in seven apple orchards of the Eva, Fuji and Gala cultivars located in the municipalities of Muitos Capões, Antônio Prado (Rio Grande do Sul state) and São Joaquim (Santa Catarina state). The orchards were divided into quadrants and sampling was carried out monthly. In each orchard, 40 plants were sampled, with three leaves of each plant collected in apical, median and basal regions of a median branch. In addition, monthly five species of spontaneous plants per orchard were sampled. A total of 8,425 mites were found, with the greatest abundance in Antônio Prado (50%), followed by Muitos Capões (35.5%) and São Joaquim (14.5%). The specimens found belong to 29 families, 64 genera and 99 species, in addition to mites of the order Oribatida. The greatest diversity was found in spontaneous vegetation (59 species), being 19 exclusives to apple trees and 21 species common to apple trees and spontaneous vegetation. Phytoseiidae was the family that presented the greatest richness, with 16 species, of which seven were common in apple trees and spontaneous plants. The most abundant species was Aculus schlechtendali Nalepa (Eriophyidae) (39.5%), followed by Panonychus ulmi (Koch) (Tetranychidae) (14.6%), Polyphagotarsonemus latus (Banks) (Tarsonemidae) (9.4%) and Neoseiulus californicus (McGregor) (Phytoseiidae) (7.4%). These results suggest that the mite fauna present in apple orchards in different landscapes and management are distinct, with a greater diversity of phytoseiid mites present in organic areas. Therefore, to maintain a greater diversity of predatory mites in these orchards, organic management seems to be the most appropriate. Furthermore, the high acarine diversity found in spontaneous vegetation demonstrates the importance of maintaining these plants in orchards that serve as refuges and reservoirs, favoring the permanence of natural enemies in these environments.

Resumo O objetivo deste estudo foi reconhecer a acarofauna associada a pomares de macieira no sul do Brasil e apresentar uma chave dicotômica das espécies amostradas e daquelas já relatadas em macieiras no sul do Brasil. Os estudos foram realizados na safra 2020/2021 em sete pomares de macieiras das cultivares Eva, Fuji e Gala localizados nos municípios de Muitos Capões, Antônio Prado (RS) e São Joaquim (SC). Os pomares foram divididos em quadrantes e a amostragem foi realizada mensalmente. Em cada pomar foram amostradas 40 plantas, sendo três folhas de cada planta coletadas nas regiões apical, mediana e basal de um ramo mediano. Além disso, mensalmente foram amostradas cinco espécies de vegetação espontânea por pomar. Foram encontrados 8.425 ácaros, com maior abundância em Antônio Prado (50%), seguido por Muitos Capões (35,5%) e São Joaquim (14,5%). Os exemplares encontrados pertencem a 29 famílias, 64 gêneros e 99 espécies, além de ácaros da ordem Oribatida. A maior abundância foi encontrada em vegetação espontânea (59 espécies), sendo 19 exclusivas de macieiras e 21 espécies comuns a macieiras e vegetação espontânea. Phytoseiidae foi a família que apresentou maior riqueza, com 16 espécies, das quais sete eram comuns em macieiras e vegetação espontânea. A espécie mais abundante foi Aculus schlechtendali Nalepa (Eriophyidae) (39,5%), seguida por Panonychus ulmi (Koch) (Tetranychidae) (14,6%), Polyphagotarsonemus latus (Banks) (Tarsonemidae) (9,4%) e Neoseiulus californicus (McGregor) (Phytoseiidae) (7,4%). Esses resultados sugerem que a acarofauna presente em pomares de macieira em diferentes paisagens e manejos são distintas, com maior diversidade de ácaros fitoseídeos presentes em áreas orgânicas. Portanto, para manter uma maior diversidade de ácaros predadores nesses pomares, o manejo orgânico parece ser o mais adequado. Além disso, a elevada diversidade de ácaros encontrada na vegetação espontânea demonstra a importância da manutenção destas plantas em pomares que servem como refúgios e reservatórios, favorecendo a permanência de inimigos naturais nestes ambientes.

Estimating intrinsic growth rates of arthropods from partial life tables using predatory mites as examples.

The intrinsic rate of natural increase of a population (rm) has been in focus as a key parameter in entomology and acarology. It is considered especially important in studies of predators that are potential biological control agents of fast-growing pests such as mites, whiteflies and thrips. Life-table experiments under controlled laboratory conditions are standard procedures to estimate rm. However, such experiments are often time consuming and may critically depend on the precise assessment of the developmental time and the fecundity rate early in the reproductive phase. Using selected studies of predatory mites with suitable life-table data, we investigated whether and how measurements of growth rates can be simplified. We propose a new method for estimating rm from partial life tables, in which the researcher can choose a level of precision based on a stand-in measure of relative error. Based on this choice, the procedure helps the researcher to decide when a life-table experiment can be terminated. Depending on the chosen precision, significant amounts of experimental time can be saved without seriously compromising the reliability of the estimated growth parameter.

Two new genera of pyroglyphid mites, Tuccioglyphus and Marioglyphus, with a key to genera of the World (Acari: Pyroglyphidae).

We describe Tuccioglyphus setosus gen. et sp. nov. from the litter of commercially reared laying hens as well as wild birds in Brazil. The new genus Tuccioglyphus presents a mixture of character states between the two conventional subfamilies, Pyroglyphinae and Dermatophagoidinae. Based on this new unusual genus, we discuss character states delimiting these and other major subfamilies of the house dust mite family, Pyroglyphidae, as well as its most important and species-rich genus Dermatophagoides. An additional new genus, Marioglyphus gen. n., is proposed for Hughesiella valerioi Vargas and Smiley. Both Tuccioglyphus and Marioglyphus are related to the genus Hughesiella. A key to pyroglyphid genera of the World is presented.