Effect of weather parameters on population dynamics of grasshoppers infesting Tuberose, Agave amica (Medikus) Thiede and Govaerts

Abstract

Tuberose (Agave amica (Medikus) Thiede and Govaerts) is a perennial garden plant belonging to the asparagus family (Asparagaceae), widely cultivated for its fragrant flowers. It is a commercially significant cut flower crop in our country, often targeted by various insect pests. Among these, grasshoppers pose a major challenge by damaging young leaves and flower buds, especially during the rainy season. This damage reduces the aesthetic appeal and market value of the plants. In light of the importance of foliar pests, a study was conducted on the population dynamics of grasshoppers at the Research Farm of the Department of Entomology, College of Agriculture (VNMKV), Latur, during 2023-2024. Results indicated that the maximum population of grasshoppers (0.23 per plant) was observed during the 47th Standard Meteorological Week (SMW) of 2023. Correlation studies of grasshoppers with weather parameters revealed that minimum and maximum temperatures had a significant negative correlation with grasshopper populations. Afternoon relative humidity exhibited a significant positive correlation, while morning relative humidity showed a non-significant positive correlation. Rainfall, on the other hand, displayed a non-significant negative correlation with grasshopper populations. These results indicate that grasshopper populations tend to decrease with rising temperatures but are positively influenced by higher afternoon relative humidity. Conversely, rainfall and morning relative humidity show limited or negligible influence on their population dynamics. The grasshopper population variation was explained by 34.7% due to the influence of different weather parameters.