Efficacy evaluation of common botanicals to manage maize weevil (Sitophilus zeamais M) in laboratory condition

Abstract

The storage of maize (Zea mays L.) is threatened by a wide range of pests; maize weevil (Sitophilus zeamais Motschulsky) being the most serious pest causing upto 32% loss of total stored grain. The experiment was carried out to find out the effectiveness of some locally available botanicals for eco-friendly management of storage pests. Completely randomized design was followed with three replications and eight treatments under room temperature at 25–28°C and relative humidity at 70±5% in Entomology Laboratory of Lamjung campus during spring season of 2017. The treatments consisted of three botanicals: Bojho (Acorus calamus), Neem (Azadirachta indica), and Titepati (Artemisia vulgaris) with two concentrations (2.5 and 5% of weight of grain); and other two treatments-Celphos tablet (standard check) and control (untreated check). Dry powders of each plant component were then mixed thoroughly with 200 g grains in plastic jars and six pairs of adult weevils were released in it. Jars were then roofed with muslin cloth and tightened with rubber band. Number of dead weevils and grain weight loss were recorded at every 30, 60 and 90 days after the application of treatments. The botanicals significantly affected weevil mortality and grain weight loss compared to untreated check, but not as effective as Celphos. Bojho rhizome powder 5% was significantly more effective among botanicals with least average weight loss of only 1.19% of grain weight and also had highest weevil mortality rate followed by Neem and Titepati with their respective highest concentration (P<0.05).