Sublethal insecticide exposure of an herbivore alters the response of its predator. (April 2019)

• Record Type: Journal Article
• Authors: Müller, Thorben; Gesing, Matthias Alexander; Segeler, Markus; Müller, Caroline
• Is Part Of: Environmental pollution. Volume 247(2019)
• Page Start: 39
• Page End: 45
• Publication Date: 2019-04
• Subjects: Insecticide carry-over -- Integrated pest management -- Lambda-cyhalothrin -- Myrmica rubra -- Phaedon cochleariae -- Pyrethroid; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2018.12.040
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Sublethal insecticide exposure poses risks for many non-target organisms and is a challenge for successful implementation of integrated pest management (IPM) programs. Next to detrimental effects of short-term insecticide exposure on fitness-related traits of organisms, also properties such as chemical signaling traits can be altered, which mediate intra- and interspecific communication. We investigated the effects of different durations of larval sublethal exposure to the pyrethroid lambda-cyhalothrin on performance traits of larvae and adults of the herbivorous mustard leaf beetle, Phaedon cochleariae . Moreover, by applying a direct contact and olfactometer bioassays, we determined the reaction of a generalist predator, the ant Myrmica rubra, towards insecticide-exposed and unexposed herbivore larvae and their secretions. Already short-term sublethal insecticide exposure of a few days caused a prolonged larval development and a reduced adult body mass of males. These effects may result from an insecticide-induced reduction in energy reserves. Furthermore, ants responded more frequently to insecticide-exposed than to unexposed larvae of P. cochleariae and their secretions. This increased responsiveness of ants towards insecticide-exposed larvae may be due to an insecticide-induced change in synthesis of chrysomelidial and epichrysomelidial, the dominant compounds of the larval secretion, which act defensive against various generalist predators. In conclusion, the results highlight that short-term insecticide exposure can impair the fitness of an herbivorous species due to both direct toxic effects and an increased responsiveness of predators. Consequently, exposure of single non-target species can have consequences for ecological communities in both natural habitats and IPM programs. Graphical abstract: Image 1 Highlights: Effects of larval insecticide exposure on performance traits are determined. Responses of an ant predator to insecticide-exposed and control larvae are tested. Insecticide exposure prolongs larval development and reduces adult male body mass. Predatory ants are more responsive to insecticide-exposed than to control larvae. Insecticide exposure may alter the larval chemical defence secretion. Abstract : Sublethal insecticide exposure of beetle larvae impairs their development and alters the response of predatory ants towards the larval secretion.