Effects of Heat Stress on Mating Behavior and Colony Development in Bombus terrestris (Hymenoptera: Apidae)

Kimberly Przybyla,Ella Zambra,Denis Michez,Elise Hennebert,Baptiste Martinet,Abigaël Anselmo,Pierre Rasmont

doi:10.3389/fevo.2021.748405

Abstract

Climate change is related to an increase in the frequency and intensity of extreme events such as heatwaves. In insect pollinators, heat exposure is associated with direct physiological perturbations, and in several species, could lead to a decrease of fitness related to a decrease in fertility. Here we developed a new experimental protocol in controlled conditions to assess if the exposure to high temperatures could modify the attractiveness and fertility of Bombus terrestris males. Our results show that virgin queens of B. terrestris do not have preferences between the pheromonal secretions of heat-exposed and control males. Moreover, mating with a heat-exposed male has no impact on the copulation behavior and the development of the nest (brood composition). We advise to extend trials to cover a range of wild and heat-sensitive species on multiple generations to better understand the impact of heat waves on the bumblebee communities.

Highlights

IntroductionClimate change is threatening worldwide biodiversity for many years in various direct (e.g., heat stress, drought) and indirect (e.g., habitat modification) ways (Bálint et al, 2011; Bellard et al, 2012; Dirzo et al, 2014)
Climate change is threatening worldwide biodiversity for many years in various direct and indirect ways (Bálint et al, 2011; Bellard et al, 2012; Dirzo et al, 2014)
With the increase in frequency and severity of heat waves (Meehl and Tebaldi, 2004; Hallmann et al, 2017) and the heat stress experienced by insects, this impact will worsen in the future and may cause negative population trends (Sales et al, 2018, 2021)

Summary

Introduction

Climate change is threatening worldwide biodiversity for many years in various direct (e.g., heat stress, drought) and indirect (e.g., habitat modification) ways (Bálint et al, 2011; Bellard et al, 2012; Dirzo et al, 2014). One of the consequences of exposure to heat stress is a loss of fertility (Walsh et al, 2019). Heat exposure can impact the viability, motility, competitiveness, and the DNA integrity of spermatozoa (Sales et al, 2018; McAfee et al, 2020; Martinet et al, 2021b). We need to develop experimental protocols to assess and understand direct impact of heat stress on insect model species. Some species have been studied to assess the impact of environmental stresses (e.g., extreme temperatures, pesticides) on individual survival and fertility (McAfee et al, 2020; Minnameyer et al, 2021; Strobl et al, 2021), but the potential consequences of sublethal effects on resulting offspring have been poorly studied (Sales et al, 2018)

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