New Entomocoenotic Particularities and Integrated Pest Control in Transylvanian Wheat Crops Under the Impact of Climate Warming

Abstract

Based on the entomological research at the ARDS Turda, the paper presents new research on pest abundance in wheat crops in relation to the climate warming in Transylvania and the adequate integrated pest control methods under different cultural soil technologies: classical (ploughing) and conservative (no tillage), in open field and in agroforestry belts agroecosystems. During 2007-2014, the study has revealed data on species composition and dynamics. Species determination has been achieved based on the samples performed every 10 days , by 100 double sweep-net catches. Were pointed out major outbreaks of abundance of thrips ( Haplothrips tritici ), as eudominant species; of wheat flies (Chloropidae and Anthomyiidae); stem flea beetles ( Chaetocnema aridula ); leafhoppers ( Javesella pellucida, Psammotettix alienus etc.) and aphids ( Sitobion avenae etc. ), as dominant groups; cereal bugs ( Eurygaster maura, Aelia acuminata ); Coleoptera: Agriotes , Zabrus tenebrioides etc. Due to aridization and climate warming, the critical attack moments have been recorded 3-4 weeks earlier and overlapped.            IPM recommends special attention to preventing measures for flies, leafhoppers, aphids, etc., which shows a high biological potential: optimal sowing time, agrotechnical methods, seed treatment with systemic insecticide and complex plant protection measures. The results proved the importance of insecticide applications: at the end of tillering phase (13-33 DC stage) and at the flag-leaf appearance and ear emergence in 45-59 DC stage. At the first treatment, cereal flies, fleas, leafhoppers, thrips, bugs etc. are controlled simultaneously, by recommending the shock (pyrethroids) or systemic insecticides (neonicotinoid etc.). At the second treatment, the ear pests are controlled simultaneously and it is recommended the shock insecticides (pyrethroids etc.) with reduced effects on the useful entomophagous. The IPM is a major section of successive soil no tillage technologies, comprising a special pest control strategy, with insecticides application on seed treatment and in 2-3 successive treatments in vegetation. Entomophagous populations are particularly abundant in open field area, in classic and in soil no tillage technologies. In the farming system with protective agro-forestry belts–favorable for increasing of entomophags species, the research pointed out the efficiency of biological control, only using the entomophagous natural resources.