Survival, development and reproduction of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) on kaolin-treated cotton

Abstract The mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a cotton pest widespread in several cotton growing regions of Brazil, particularly in the semi-arid region of southwestern Bahia. The impact of kaolin on survival, development and reproduction of P. solenopsis was evaluated in the laboratory. The experiment was developed in a completely randomized design with two treatments: immature or newly emerged adults of P. solenopsis sprayed with kaolin and fed with cotton leaf discs treated with kaolin suspension (with kaolin) (T1) and immature or newly emerged adults of P. solenopsis sprayed with distilled water and fed with cotton leaf discs treated with distilled water (without kaolin) (T2). The kaolin suspension shortens the life cycle, increases the reproductive potential and population growth of the cotton mealybug, P. solenopsis and, therefore, it should be used with caution on cotton plants in regions with a history of occurrence of this pest.摘要 扶桑绵粉蚧（Phenacoccus solenopsis Tinsley，半翅目（Hemiptera）粉蚧科（Pseudococcidae））是广泛分布于巴西多个棉花种植区的棉花害虫，尤其在巴伊亚州西南部的半干旱区域发生为害。本研究在实验室条件下评估了高岭土（kaolin）对扶桑绵粉蚧存活、发育及繁殖的影响。实验采用完全随机设计，设置两组处理：T1组为经高岭土喷雾处理且饲喂高岭土悬浮液处理的棉花叶碟的扶桑绵粉蚧若虫或初羽化成虫；T2组为经蒸馏水喷雾处理且饲喂蒸馏水处理的棉花叶碟的扶桑绵粉蚧若虫或初羽化成虫（无高岭土处理组）。研究结果显示，高岭土悬浮液会缩短扶桑绵粉蚧的生活史周期，提升其繁殖潜力与种群增长速率，因此在该害虫有发生历史的棉花种植区域，使用高岭土时需格外谨慎。