Cotton Bollworm (Helicoverpa armigera) a Threat to Maize Crops in Romania

Emil Georgescu¹, Lidia Cană¹, Cristina Radu², Cristina Cionga²,
Paula-Lucelia Pintilie³, Luxița Rîșnoveanu^4,5

¹National Agricultural Research and Development Institute Fundulea
²Romanian Professional Farmers and Processors Forum
³Agricultural Research and Development Station Secuieni
⁴Agricultural Research and Development Station Brăila
⁵University Economic Studies of Bucharest

Keywords: cotton bollworm, high population, maize.

 Abstract: This paper presents a five-year study concerning monitoring the cotton bollworm (Helicoverpa armigera) flight dynamics using pheromone traps and a study relating to the behaviour of nine maize hybrids from two maturity groups to this pest attack in 2024. The monitoring and field assessments were made in south-east Romania, Călărași County, at the NARDI Fundulea. During the monitoring period, from 2020 to 2024, air temperature was higher than average in the summer months while rainfall was below average, except in June 2021. Total captured moths in the traps were 246 in 2020, 406 in 2021, 5064 in 2022, 1024 in 2023, and 4145 in 2024. In the middle of July 2022, the average captured moths per trap were 483.3; in the middle of September, it was 589.0 catches. In 2024, in the last 10 days of July, the average captured moths per trap were 311.7, in the last 10 days of August, it was 358.0, while in the middle of September, it was 362.3. In 2024, at the beginning of August, the attack incidence of corn earworm on maize hybrids ranged from 43.75 to 53.75 %, and on 13 September, it was 100% at all hybrids. In September 2024, at all maize hybrids from this study, the pest attack incidence on cobs was 100%. We analyse the maize hybrids' yield for total aflatoxins (B1 + B2 + G1 + G2) level. Because of high pest attacks in 2024, the aflatoxin was higher than maximum limits (Reg. EC 1881/2006) at all hybrids from this study. This is the first report from southeast Romania that mentioned a higher population of cotton bollworm in the late summer and beginning of autumn, and the first report that mentioned high pest attacks on maize cobs in September.