NEW DATA ON KNOWLEDGE OF PEST ENTOMOFAUNA AND ECOLOGICAL PARAMETERS FOR RAPESEED, SUNFLOWER AND CORN CROPS

Abstract

In the period 2019-2022, at A.R.D.S. Secuieni through the implementation of the ADER 2.2.1. project, the series of observations and determinations on appearance and evolution of harmful entomofauna in rapeseed, sunflower and corn crops continued. The pests monitoring was carried out by ground surveys with a metric frame (25/25 cm), yellow bowl traps, Barber and yellow glue traps from crop emergence until plants mature. The collected material was subjected to a mathematical analysis to calculate the ecological parameters: abundance (A), dominance (D), constancy (C) and the index of ecological significance (W) which highlight the characteristics of the analyzed biocenosis. Recorded data showed that in rapeseed, the harmful entomofauna included 20 pest species that totalled on average 1207 specimens per year, whose abundance had maximum values ​​of 523 specimens/year at the species Ceuthorynchus pallidactylus. The rapeseed species were classified into four classes of dominance, four classes of constancy and five classes of the ecological significance index. In sunflower, the harmful entomofauna consisted of 16 species, which totalled an average of 504 specimens annually, with abundance values ​​between 1 and 182 specimens. Of the 16 species, three were classified in the D5 dominance class, two in the D4 class, five in the D3 class, and six in the D1 class as well as in classes C1 and C2. In terms of the index of ecological significance, Harpalus sp. fell into the W3 class, the rest of species being into the W1 and W2 classes. In corn, the entomofauna was also composed of 16 species totalling an average of 3720 specimens/year. The species Diabrotica virgifera virgifera had the highest abundance (2388 specimens) classified in the class of D5 dominance, C3 constancy and W5 index of ecological significance. The entomofauna harmful to rapeseed, sunflower and corn crops is quite numerous in terms of species and specimens number, which requires permanent monitoring and the application of appropriate measures to prevent attacks and control.