Research on the Structure and Abundance of Beetles (Ord. Coleoptera)from Some Corn Crops in Northern Moldova-Romania

Abstract

Within this station, three experimental variants were initiated that targeted the preceding culture. Therefore, the variants studied were: V1 maize in monoculture; V2 corn after sunflower; V3 corn after wheat. Barber-type soil traps were used to collect biological material, they worked continuously from April to July 2021, where a number of 5 collections were made for each variant. Barber traps consist of plastic containers of approx. 10-12 centimeters high and about 8-10 centimeters in diameter in which I used a salt solution (NaCl) with a concentration of about 20% as fixing liquid. Six traps were used for each experimental variant. Samples were collected at 12-15 day intervals when we changed the fixative – saline solution, replenished or, if necessary, replaced. The collected species were cleaned of all plant remains, other impurities, and then the coleoptera species were selected separately, and with the help of determinants they were identified. The structure, dynamics and abundance of coleopteran species were then determined according to each experimental variant, and the most frequently collected were: Tanymecus dilaticollis, Epicometis hirta, Coccinela 7- punctata, Harpalus calceatus, Harpalus distinguendus Formіcomus pedestrіs, Phyllotreta vittula, Opatrum sabulosum and Pentodonidiota.