Institut de Recherche sur la Biologie de l'Insecte, UMR7261, CNRS, University of Tours, Tours, France.
Laboratoire de Physiologie de la Reproduction & des Comportements, UMR 7247 INRAE/CNRS/Université de Tours/IFCE, Nouzilly, France.
Environ Sci Pollut Res Int. 2022 Oct;29(48):72729-72746. doi: 10.1007/s11356-022-20970-z. Epub 2022 May 25.
Sublethal exposure to pesticides can alter the survival and reproduction of a wide range of non-target organisms. However, it remains unclear whether this exposure can alter behaviours that are often essential for long-term population dynamics and maintenance, such as parental care. In this study, we tested the effect of pyriproxyfen exposure (an insect growth regulator) on maternal care in the European earwig, an insect that is both used in pest control in pip-fruit orchards and considered a pest in stone fruit orchards. We exposed 424 females at doses either 10 times lower, equivalent or 10 times higher than normal application rates in French orchards. As maternal care can change over the weeks of family life, we exposed the earwig mothers at five different days before and after egg hatching. We then measured the expression of ten forms of maternal care towards eggs and juveniles, six non-caring behaviours, eggs and juvenile development, metabolic reserves in mothers at egg hatching and females' production of a terminal clutch. First, our results revealed that the three tested doses of pyriproxyfen were non-lethal and confirmed that maternal care decreased throughout both pre- and post-hatching family life. However, we did not detect any effect of pyriproxyfen on maternal care and non-care behaviours, eggs and juvenile development, quantities of lipids, proteins and glycogen in mothers at egg hatching, and on the production of a future clutch. Overall, these findings suggest that the maximal doses of pyriproxyfen authorized in French orchards is likely to have limited effects on the short- and long-term maintenance of populations of the European earwig and raises fundamental questions about the nature of the link between juvenile hormone and parental care in insects.
亚致死浓度的农药暴露会改变广泛的非靶标生物的生存和繁殖。然而，目前尚不清楚这种暴露是否会改变对长期种群动态和维持至关重要的行为，例如亲代抚育。在这项研究中，我们测试了吡丙醚暴露（一种昆虫生长调节剂）对欧洲螽斯的亲代抚育的影响，欧洲螽斯既被用于核果果园的害虫防治，又被认为是核果果园的害虫。我们在剂量上分别暴露了 424 只雌性，剂量分别比法国果园的正常施用量低 10 倍、相等或高 10 倍。由于亲代抚育可以在家庭生活的几周内发生变化，我们在卵孵化前和后 5 天暴露螽斯母亲。然后，我们测量了对卵和幼虫的十种形式的亲代抚育、六种非抚育行为、卵和幼虫发育、卵孵化时母亲的代谢储备以及雌性产卵的终末卵囊的表达。首先，我们的结果表明，吡丙醚的三种测试剂量均无致死性，并证实亲代抚育在孵化前和孵化后家庭生活中都减少了。然而，我们没有发现吡丙醚对亲代抚育和非抚育行为、卵和幼虫发育、母亲在卵孵化时的脂质、蛋白质和糖原的数量以及未来卵囊的产生有任何影响。总的来说，这些发现表明，法国果园授权的吡丙醚最大剂量可能对欧洲螽斯种群的短期和长期维持影响有限，并对昆虫中保幼激素与亲代抚育之间的关系的本质提出了基本问题。
