PREVALENCE AND MANAGEMENT OF INSECT PESTS OF RED AMARANTH (LALSHAK), AMARANTHUS GANGETICUS AND IT’S NATURAL ENEMIES

Abstract

An experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Dhaka during the period of rabi season November 2016 to February 2017 to investigate the prevalence and management of sucking and chewing insect pest of red amaranth (Lalshak), Amaranthus gangeticus. Lalshak variety BARI I was used as test crop for the experiment. The experiments consists of 7 treatments as T1: Mechanical method + Cultural method at 7 days interval, T2: Spraying soap water @ 1.5 g detergent/L of water at 7 days interval, T3: application wood ash @ 10 g/m2 at 7 days interval, T4: Spraying of neem leaves extract @ 20 g/L of water at 7 days interval, T5: Spraying neem seed kernel @ 20 g/L of water at 7 days interval, T6: Spraying malathion 57EC @ 1.5 ml/L of water at 7 days interval and T7: Untreated control. The experiment was laid out following Randomized Complete Block Design (RCBD) with three replications. Data was recorded on pest incidence, abundance of beneficial insects and leaf infestation due to different insect pests. As insect pests grasshopper, red pumpkin beetle, green leaf eating caterpillar, green stink bug, leaf miner, white fly and jute hairy caterpillar was observed. As beneficial insect population, lady bird beetle, specid wasp, bee wolf and braconid parasite was observed for different management practices. The infested leaves/plant by grasshopper, red pumpkin beetle, green leaf eating caterpillar, green stink bug, leaf miner, white fly and jute hairy caterpillar were 2.16, 2.37, 3.49, 1.11, 2.22, 3.33 and 4.44 percent respectively found into treatment which are the lowest among the treatment, while the highest infestation for same insect pests (12.04%, 15.85%, 15.56%, 15.56%, 17.78%, 21.11% and 18.89%) was observed in T7 treatment. Among the different insect pests management practices, spraying of malathion 57EC @ 1.5 /L of water at 7 days interval was better for controlling insect pests of red amaranth with lowest infestation level.