Lygus species (Hemiptera: Miridae), their distribution, and population dynamics in cotton production areas in Diyarbakır province, Türkiye.

Many insect pests infest cotton (Gossypium hirsutum L.) crop, resulting in significant economic losses. The tarnished plant bugs (Lygus species) greatly damage the cotton crop during all growth stages. This study determined Lygus species infesting cotton in Diyarbakır province, their distribution, and population dynamics during 2020 and 2021. Lygus species samples were collected from 244 fields in 7 districts of the province by using either D-vac or sweep net based on the phenological period of cotton. Population dynamics of the species were monitored weekly by using sweep net and D-vac from two fields situated in the Sur (Gencan village) and Çınar (Şükürlü village) districts of the province during both years. Two species including Lygus gemellatus (Herrich-Schäffer) and L. pratensis (Linnaeus) were identified during the study. Lygus gemellatus was the most common and abundant species observed in 91.2% and 74.7% of the surveyed fields during 2020 and 2021, respectively. The species were recorded at the end of May (before flowering) during both years, and their populations increased afterward. The peak population of both species was observed during the boll maturation period. The D-vac trapped a statistically higher number of Lygus bugs than the sweep net at Gencan (p <0.05), while both methods trapped statistically similar numbers of bugs at Şükürlü. It is concluded that the population density of both species can change from year to year depending on biotic and abiotic factors. It is suggested that survey studies must be conducted at the start of a vegetative period of cotton to monitor these species. [ABSTRACT FROM AUTHOR]