IMPACT OF VARIOUS WEATHER PARAMETERS ON INSECT PESTS COMPLEX OF MUSTARD IN MANDAWAR REGION OF HARIDWAR DISTRICT UTTARAKHAND INDIA

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The present study on mustard crops was conducted at the Agricultural Research Field of Quantum University in Roorkee, Uttarakhand during the year 2023-24. The research identified the presence of insect pests such as flea beetles, mustard sawflies, and aphids affecting mustard plants during the nursery phase as well as at the bloom and pod initiation stages. The initial populations of flea beetles, sawflies, and aphids were noted in the 42nd, 44th, and 46th Standard Meteorological Weeks, respectively. A gradual rise in the flea beetle population was recorded in the 44th SMW, with an average of 2.00 beetles per plant, while the peak population was observed in the 47th SMW, reaching 5.00 beetles per plant. Both larvae and adult stages of sawflies were documented, with the highest number of larvae recorded in the 50th SMW, totaling 3.67 flies per plant. Data on aphid populations were collected from the flower initiation stage through to pod maturation. A significant increase in aphid populations was noted, with the highest count occurring in the 7th SMW under favorable conditions of 23°C and 87% relative humidity. The correlation coefficient between flea beetles and weather parameters indicated a positive relationship with temperature (r max = 0.14 and r min = 0.67), whereas the correlation with sawflies was negative (r max = -0.23 and r min = -0.37). Similarly, a negative correlation was observed for aphids (r max = -0.58**, r min = -0.66**). Among all weather parameters, only rainfall exhibited a negative correlation with all three insect species in the field. The coefficient of determination (R2 ) indicated variability in insect populations, with values of 0.32, 0.38, and 0.65 for flea beetles, sawflies, and aphids, respectively. Therefore, weather parameters play a crucial role in the buildup of insect populations under field conditions. By understanding the timing of insect incidence on crops, appropriate and effective management practices can be implemented to maintain insect populations below injury levels without adversely affecting beneficial insects in the field.