Integrated Pest Management Strategies for Sustainable Management of Black Thrips, Thrips parvispinus (Karny)  in Chrysanthemum Cultivation

Chrysanthemum (Dendranthema grandiflora L.), a prominent ornamental flower in the Asteraceae family, is widely cultivated for its aesthetic and medicinal value. However, the increasing prevalence of the invasive pest, Thrips parvispinus (Karny) poses a significant threat, causing substantial qualitative and quantitative losses. Despite its economic importance, studies on effective integrated pest management (IPM) strategies targeting T. parvispinus remains limited. This study aimed to evaluate the the potential of combining cultural, mechanical, biorational, and chemical strategies for sustainable pest management. Field experiments were conducted in Dasarapalli, Krishnagiri district, Tamil Nadu during 2022-2023 to assess efficacy of four IPM modules against T. parvispinus in chrysanthemum cultivation. Four IPM modules were tested in Dasarapalli, Krishnagiri district, during 2022–2023. Among the tested modules, Module I comprising a seedling root dip, mulching, blue sticky traps, and the application of Pongamia soap (5 g/L) alongside need-based chemical insecticides, specifically Spinosad 45% SC at 0.2 mL/L proved most effective. It recorded a mean thrips incidence of 18.85 per flower and the highest yield of 19.76 tonnes per hectare, demonstrating superior pest control and enhanced crop productivity. Challenges such as environmental variations and the complex behavior of T. parvispinus highlighted the need for adaptive IPM strategies. While other IPM modules showed moderate effectiveness, complementary evaluations of individual treatments revealed that Pongamia soap (5 g/L) achieved a 74.90% reduction in thrips incidence, making it the most effective biorational. Among chemical insecticides, Spinosad 45% SC (0.2 mL/L) demonstrated the highest efficacy, reducing the thrips population by 80.2%. These findings underscore the importance of integrating environmentally friendly biorationals with targeted chemical applications and cultural practices. The superior performance of Module I illustrates the potential for sustainable and eco-friendly chrysanthemum cultivation by minimizing chemical dependence. This study provides valuable insights for developing practical IPM strategies to address the challenges posed by invasive thrips species.