Population Dynamics of Pests Infesting Guava in Relation to Weather Parameters in Southern Karnataka, India
Hema, A.P.
Department of Agricultural Entomology, College of Sericulture, Chintamani-563125, University of Agricultural Sciences, Bengaluru, India.
Manjunatha, R.
AICRP on Sunflower, University of Agricultural Sciences, Bengaluru-560065, India.
Manjunatha, K.L. *
AICRP on Post Harvest Engineering and Technology (ICAR), University of Agricultural Sciences, Bengaluru-560065, India.
Narasa Reddy, G.
Department of Agricultural Entomology, College of Sericulture, Chintamani-563125, University of Agricultural Sciences, Bengaluru, India.
Veena, B
AICRP on Post Harvest Engineering and Technology (ICAR), University of Agricultural Sciences, Bengaluru-560065, India.
Sanjay, H.N.
Department of Agricultural Entomology, College of Sericulture, Chintamani-563125, University of Agricultural Sciences, Bengaluru, India.
*Author to whom correspondence should be addressed.
Abstract
The present investigation on the seasonal incidence of pests infesting guava was conducted at Krishi Vigyan Kendra, Chintamani campus, Karnataka, from July 2023 to June 2024. A total of fifteen species of insect pests were recorded, belonging to the orders Hemiptera (10 species), Coleoptera (2 species), Diptera (2 species), and Lepidoptera (2 species). Among the sucking pests, Aphid (Greenidea psidii, 24.44 per 20 trees), Scale insect (Ceroplastes cirripediformis, 3.99 per 20 trees), cottony cushion scale (Icerya purchasi, 1.67 per 20 trees), and whitefly (Aleurodicus dispersus, 179.56 per 20 trees), exhibited populations peaks in November 2023. Scale insects Pulvinaria psidii and Parasaissetia nigra showed higher populations in June, with mean numbers of 2.76 and 2.67 per 20 trees, respectively. The fruit fly population reached its peak in August, with an average of 487 flies per trap. Infestation by Helopeltis spp. was highest during August, with a population of 4.67 per 20 trees. Correlation analysis revealed that total rainfall had a significant positive correlation (r=0.658) with the population of B. dorsalis. Maximum temperature is negatively correlated with the populations of Greenidea psidii (r=0.682), Ceroplastes cirripediformis (r=0.659), Ferrisia virgate (r=0.641), and Aleurodicus disperses (r=0.733). The minimum temperature is positively correlated with Holotrichia serrata (r=0.883*), Myllocerus spp. (r=0.730*), Pulvinaria psidii (r= 0.652*) and Perissopneumon ferox (0.700*), whereas negatively correlated with Ferrisia virgate (r=0.673*), Aleurodicus disperses (0.676*). The relative humidity is positively correlated with Ceroplastes cirripediformis (0.709*), Ferrisia virgate (0.607*), Labioproctus poleii (0.577*), and Greenidea psidii (r=0.669*). Overall, pest dynamics in guava were closely linked to abiotic factors, underscoring these factors are crucial for timely forecasting and the development of eco-friendly management strategies.
Keywords: Population fluctuation, insects, abiotic factors, correlation, guava