Insect pests are one of the main factors responsible for the decline in the production of agricultural crops, and their incidence and impact are to a large extent determined by weather and climate conditions, which are constantly changing. For example, in the corn crop in the western part of Romania, 3 pests, Ostrinia nubilalis, Helicoverpa armigera and Diabrotica virgifera virgifera, play a key role in the potential long-term impacts of climate change on productivity. The ecological responses of the 3 pests to recent climate change are already visible and are mainly associated with the increase in temperature and the lack of rainfall from 2022 onwards, causing major imbalances in the corn crop and leading to extremely high populations of these pests with significant production losses. Therefore, as the conditions of their occurrence have changed at a high rate, the aim of this paper was to monitor the 3 target pests through the lens of abundance and population dynamics. The research was conducted in 2022 and the experimental plots were located in Clarii Vii (Jimbolia) (45°49′44.7″N 20°48′24.6″E), the total experimental fields being of : 64,134 m2. DEKALB DKC 4598 maize hybrid was used. Monitoring was performed between May and September 2022 by placing Csalomon pheromone traps in the experimental plot: -VARL+ - for O. nubilalis, RAG - for H. armigera and PALz - for D. virgifera virgifera. The traps were installed on 23 May 2022 at a rate of 2 traps per hectare, the readings were taken every 7 days and the change of the sexual pheromone was carried out at an interval of 4 weeks. The first individuals appeared in the week 23rd - 27th May (BBCH maize 6 - 8 leaves) with an average of 9.2 adults/trap/day for O. nubilalis, 8.6 adults/trap/day for H. armigera; and the first individuals of D. virgifera virgifera appeared on 17th June with an average of 56.3 adults/trap/day. The maximum abundance of the first generation was reached on 17 June for O. nubilalis (15.8 adults/trap/day) and on 23 June for H. armigera (11.1 adults/trap/day). With an average of 19.8 adults/trap/day for O. nubilalis and 13.8 for H. armigera, the maximum threshold for the second generation is reached on 6 August 2022. The species D. virgifera virgifera, which has only one generation/year, reaches the maximum on 8 September 2022 with an average of 359.6 adults/trap/day. The results of the present study showed that occurrence had a positive, non-significant correlation with minimum and maximum temperature. Relative humidity was the other most important factor that was closely related to the activity of the pests. In the case of precipitation, a positive, significant correlation was found.

pests, corn, climatic factors, abundance, population dynamics

biology

Presentation: poster