Abstract
Stress tolerance and adaptation to stress are known to facilitate species invasions. Many invasive species are also pests and insecticides are used to control them, which could shape their overall tolerance to stress. It is well-known that heavy insecticide usage leads to selection of resistant genotypes but less is known about potential effects of mild sublethal insecticide usage. We studied whether stressful, sublethal pyrethroid insecticide exposure has within-generational and/or maternal transgenerational effects on fitness-related traits in the Colorado potato beetle (Leptinotarsa decemlineata) and whether maternal insecticide exposure affects insecticide tolerance of offspring. Sublethal insecticide stress exposure had positive within-and transgenerational effects. Insecticide-stressed larvae had higher adult survival and higher adult body mass than those not exposed to stress. Furthermore, offspring whose mothers were exposed to insecticide stress had higher larval and pupal survival and were heavier as adults (only females) than those descending from control mothers. Maternal insecticide stress did not explain differences in lipid content of the offspring. To conclude, stressful insecticide exposure has positive transgenerational fitness effects in the offspring. Therefore, unsuccessful insecticide control of invasive pest species may lead to undesired side effects since survival and higher body mass are known to facilitate population growth and invasion success.
Highlights
Increase fitness[12,13,14]
Considering the harm that invasive pest species pose to the environment and agriculture, it is important to study how insecticide stress affects performance and population dynamics within a generation, and whether sublethal doses lead to transgenerational cost or benefits
We show that exposure to sublethal pyrethroid insecticide stress can induce both positive within- and transgenerational effects manifested as higher survival and higher adult body mass of the Colorado potato beetle, which may have implications for the invasion success of the species
Summary
This phenomenon, where exposure to low levels of stress can induce stimulatory effects but is lethal at higher exposure levels, is known as hormesis[14] This phenomenon has been demonstrated on maize weevil (Sitophilus zeamais) where exposure to sublethal doses of pyrethroid insecticide lead to a peak in the net reproductive rate[15]. The investigation of transgenerational effects is relevant for invasive pest insects, including the Colorado potato beetle, because they can have multiple generations per year that are exposed to the same insecticide. Possible effects on body mass are important because higher body mass is associated with higher reproductive performance, survival and overall increased fitness (including overwintering survival)[31] All these traits are relevant as they can facilitate the invasion of the beetle towards northern latitudes as well as generally increase its severity as a pest
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
