NEW DATA ON ENTOMOFAUNA HARMFUL TO RAPESEED CROPS AND THE ESTABLISHMENT OF MEASURES TO PREVENT AND REDUCE ATTACKS

Abstract

"Rapeseed, the first crop established in autumn, is a species that attracts a large number of pests, from emergence to the siliquae formation and seed. Decreased production due to the attack of harmful insects can vary between 30-50%, in certain years, they can completely compromise crops. This paper presents data on the entomofauna harmful to rapeseed crops and the influence of measures to prevent and combat attacks, under specific conditions in the Central area of Moldova. The results obtained between 2017 and 2020 showed that the harmful entomofauna of rapeseed was composed of 23 species of insects, classified in five systematic orders: Coleoptera, Lepidoptera, Heteroptera, Hymenoptera and Homoptera. According to the number of species and the number of specimens collected, the order Coleoptera had the maximum share of 73.9% and respectively 88.9%. Within the order Coleoptera, the most abundant species were Phyllotreta atra (41.4%), Meligethes aeneus (27.8%), Ceuthorynchus assimilis (9.6%) and Phyllotreta nemorum (7.3%). Out of the total pest entomofauna, it was found that 30% affect rapeseed crops in the period between seed germination-plant emergence-leaf rosette formation, 9.1% in budding phase, 38% in flowering and 1.8% up to 2.8% in the phenophases of siliquae formation and seed. To prevent the attacks of soil pests (P. atra, P. nemorum, Psylliodes sp., Athalia rosae) was achieved by chemical treatment of the seed with Imidacloprid, Clothianidin and Thiamethoxam. The product Lumiposa 625FS-11.4 l/t seed was experimented with good results in seed treatment. To reduce the attacks of the pests during the flowering period (M. aeneus, A. rosae, Epicometis hirta, Ceuthorynchus assimilis) three treatments were applied on vegetation as follows: Decis Mega-0.075l/ha; Biscaya-0.3 l/ha; Mavrik-0.2 l/ha. This work was carried out within ADER 4.1.5 and 2.2.1 projects."