Reduced-rate buprofezin and mineral oil for management of Kilifia acuminata (Hemiptera: Coccidae) in mango orchards: Field efficacy, persistence, and assessment of putative synergism

Abstract

Kilifia acuminata (Signoret) (Hemiptera: Coccidae) is an important soft scale associated with mango production in Egypt and other tropical and subtropical regions. The present field study evaluated whether reduced-rate buprofezin, a chitin-synthesis-inhibiting insect growth regulator, and a summer mineral oil could provide persistent suppression of K. acuminata when applied singly or as a binary treatment. The experiment was conducted on mango trees at the Central Laboratory for Agricultural Climate, Giza, Egypt, on 9 July 2025. Four treatments were compared: untreated control, one-half of the recommended rate of buprofezin (Fitify 50% WG), one-half of the recommended rate of KZ 95% EC summer mineral oil, and the corresponding half-rate binary mixture. Pest abundance was assessed before treatment and weekly for six weeks. Corrected reduction was calculated using the Henderson and Tilton approach specified in the source protocol. The binary treatment produced 100% corrected reduction at every weekly assessment. Mineral oil alone averaged 99.96% corrected reduction across six weeks, whereas buprofezin alone averaged 96.78%, with a slower Week-1 response (82.52%). Exploratory one-way ANOVA using the three canopy-level spreadsheet rows as observational units showed no pretreatment difference (F3,8 = 1.76, p = .232) but significant treatment effects at all post-treatment assessments (p <= .0137). Tukey comparisons separated the untreated control from all treated groups but not the treated groups from each other. Although the mixture gave complete and persistent suppression, the exceptionally high efficacy of mineral oil alone generated a ceiling effect. An exploratory Bliss-independence comparison therefore provided no biologically meaningful evidence of true synergism. The practical novelty of this work is the reduced-input field comparison of half-rate buprofezin, half-rate mineral oil, and their binary combination against K. acuminata over six consecutive weeks. The mixture is best interpreted as a highly effective reduced-rate treatment whose formal synergistic status requires confirmation using true block-level replicate data in a factorial repeated-measures model.