Entomology Section, Central Cotton Research Institute, Multan, 60000, Pakistan.
Pesticides and Environmental Toxicology Laboratory, Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia.
Chemosphere. 2021 Feb;265:129118. doi: 10.1016/j.chemosphere.2020.129118. Epub 2020 Nov 26.
Dysdercus koenigii, a serious cotton-staining insect pest in many countries, has shown high resistance to imidacloprid, a systemic neonicotinoid insecticide used to control sap-sucking pests. With the aim of creating an effective management strategy, the biological traits of susceptible (SS) and imidacloprid-resistant (Imida-RS) D. koenigii, as well as their reciprocal crosses (CR1 and CR2), were investigated here using a life table established on age, stage, and two-sex patterns. Compared with SS D. koenigii, Imida-RS and CR1 strains had lower relative fitness (0.80 and 0.47, respectively) and fecundity (eggs per female); prolonged egg duration and a prolonged adult preoviposition period; shorter nymphal duration, male/female total longevity, and oviposition days, and a shorter total preoviposition period. However, there were no differences among strains in nymphal survival rates and female ratio. The CR2 D. koenigii had similar relative fitness value (1.09), suggested no fitness cost in most of the parameters. Demographic parameters, including net reproductive rate, were lower in the Imida-RS strain than in SS and CR2 D. koenigii. Similarly, the Imida-RS and CR1 strains had shorter generation time and doubling time, lower reproductive value and life expectancy relative to the SS and CR2 D. koenigii. In addition, age-specific fecundity was negatively affected in the CR1 strain compared with the other strains. These findings could help facilitate the development of rational D. koenigii control strategies.
横纹尾夜蛾是许多国家严重为害棉花的刺吸式口器害虫，对用于防治此类害虫的内吸性新烟碱类杀虫剂吡虫啉已产生了高水平抗性。为了制定有效的防治策略，本研究采用龄期-龄期-两性生命表技术，调查了敏感品系（SS）和吡虫啉抗性品系（Imida-RS）以及它们正反交后代（CR1 和 CR2）的生物学特性。与 SS 品系相比，Imida-RS 和 CR1 种群的相对适合度（分别为 0.80 和 0.47）和繁殖力（每头雌虫产卵量）较低；卵期延长，雌成虫产卵前期延长；若虫期、雌雄成虫总寿命和产卵天数缩短，总产卵前期缩短。然而，各品系间若虫存活率和雌虫比例无差异。CR2 种群的相对适合度值（1.09）与 SS 和 CR2 种群相似，表明在大多数参数中不存在适合度代价。Imida-RS 种群的净生殖率等种群参数均低于 SS 和 CR2 种群。此外，Imida-RS 和 CR1 种群的世代时间和加倍时间较短，生殖值和期望寿命均低于 SS 和 CR2 种群。与其他种群相比，CR1 种群的特定年龄生育力降低。这些结果有助于制定合理的横纹尾夜蛾防治策略。
