Field efficacy of botanicals and beneficial microbes to control banana mealybug (Pseudococcus elisae Borchsenius) (Hemiptera: Pseudococcidae)

Abstract

The banana mealybug (Pseudococcus elisae Borchsenius) causes significant economic losses to banana production. Prior to the 2019 ban of the organophosphate chlorpyrifos use in commercial banana production systems due to high chlorpyrifos residue levels on banana fruits, chlorpyrifos-treated exclusion bags were commonly used to mitigate mealybug infestation on banana bunches and fingers. Short- and long-term effects of 2 beneficial microbes (Beauveria bassiana and Kosakonia radicincitans), 2 neem-based botanicals (Orgamix and Rata®), 3 chemical insecticides Pyriforce® (Chlorpyriphos-ethyl), Calixine Super® (Acetamipride and Bifenthrin), and Parastar EC40® (Imidachlorpride and Lambda-cyhalothrin), and tap water (Control) were evaluated on mealybug in a newly established and 5-year-old banana farms. Mealybug sampling was conducted for three months after each insecticide application and their population dynamics was calculated using Mann-Kendall trend statistics (S). For the 5-year-old banana farm, except the control, all treatments caused significant (P < 0.05) short-term reduction in mealybug population from pre-treatment application to 5 days in March, July and November samplings. Mealybug population reduction in March was greater than 90% for Calixine Super®, Orgamix and Beauveria, and between 80% and 90% for Kosakonia, Rata and Parastar EC40® (P < 0.05). A similar trend was recorded in July and November, with a higher reduction for Beauveria (52.08%) in July. An increasing linear mealybug trend was observed between March and June (S was positive, P > 0.05) across all treatments, while Orgamix and Rata® caused downward trend between July and October. A downward mealybug trend occurred for Parastar EC40® (S = −1), Rata® (S = −3), Beauveria (S = −6) and Kosakonia (S = −3) between November and January. Biorationals effectively reduced mealybug populations better than chlorpyrifos, while beneficial microbes and neem-based botanicals demonstrated long-term potency on mealybug.