Resistance of "Aphis gossypii" to sulfoxaflor is reversible

Researchers have identified increased resistance in Aphis gossypii to the pesticide sulfoxaflor. Although effective against populations resistant to other products, the intensive use of this insecticide has caused resistance in several regions of China. However, a study indicates that resistance is not permanent and can be reversed under controlled conditions.

Key Findings

• Unstable resistance: after 22 generations without exposure to sulfoxaflor, the resistance of Aphis gossypii reduced from 51,57 times that of the susceptible strain to 1,11 times. This reversal suggests that temporary withdrawal of the pesticide may restore its effectiveness.

• Reduction in biological fitness: Despite resistance reversal, previously resistant aphids demonstrated reduced biological fitness, including reduced longevity, fecundity, and reproductive efficiency. This competitive disadvantage is a cost associated with resistance, indicating that reversion does not fully restore normal biological parameters.

• Altered eating behavior: resistant aphids had greater difficulty accessing plant phloem nutrients, which are essential for plant growth. The reduced ability to feed efficiently may explain the decreased fitness.

• Sublethal impacts of sulfoxaflor: At sublethal concentrations, sulfoxaflor had negative effects on the feeding of susceptible strains, significantly reducing the duration of phloem ingestion. However, resistant and partially reverted strains (Sul-R and Sul-D) were not affected in the same way.

According to the scientists, these results reinforce the need for integrated resistance management strategies, such as insecticide rotation and reduction of indiscriminate applications. These practices can prolong the effectiveness of compounds such as sulfoxaflor and minimize the economic and ecological impacts of excessive chemical control.

More information can be found at doi.org/10.3390/insects15120920