The neonicotinoid thiamethoxam impairs male fertility in solitary bees, Osmia cornuta

Thiamethoxam as an inadvertent anti-aphrodisiac in male bees

“…The data confirm that thiamethoxam exposure can elicit sublethal effects on sperm traits [ 32 , 33 ], revealed by the reduction in drone sperm quantity, viability and total living sperm quantity by 17%, 10% and 23% compared to controls, respectively. The reduced sperm quantity suggests that thiamethoxam may hinder the migration of sperm from the testis to the seminal vesicles in bumblebees, as spermatogenesis and spermiogenesis are both completed upon emergence in bees [ 87 ].…”

“…Further, spiders and moths showed reduced courtship behaviour due to reduced contact chemoreception functioning and mating calling [ 36 , 37 ], respectively. Given such effects hold true for bee species, combined with negative effects on sperm traits as previously observed [ 32 ], this may have drastic consequences for entire populations.…”

“…Moreover, these neurotoxins are known to elicit a wide array of sublethal effects on pollinating bees, such as inducing hyper- or hypoactivity, which can impair flight and feeding behaviour [ 27 , 28 ]. Furthermore, neonicotinoid exposure has been shown to reduce offspring production [ 29 , 30 ] and impair reproductive physiology in females and males by reducing ovary development and sperm capacities [ [31] , [32] , [33] ]. However, to our knowledge, no data exist on the effects on male bee mating behaviour and mating success in combination with fertility, despite such effects being shown in other arthropod species.…”

Low toxicity crop fungicide (fenbuconazole) impacts reproductive male quality signals leading to a reduction of mating success in a wild solitary bee

“…Honeybee drones, for example, lose the viability of their spermatic cells when they are exposed to neonicotinoids (clothianidin and thiamethoxan) as well as amitraz and miticides at an immature developmental stage (Fisher II & Rangel, 2018; Straub et al, 2016). Moreover, clothianidin and thiamethoxam have adverse effects on the sperm viability of solitary mason bees (Strobl, Albrecht, et al, 2021; Strobl, Bruckner, et al, 2021) suggesting different toxicity levels in the reproductive cells of solitary male bees of the genus Osmia .…”

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

“…With an annual economic value of 153 billion dollars (USD) for crop pollination (Potts et al, 2016), insect pollinators, wild and domesticated, are a key functional group to conserve (Williams, 1994). Recently, 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).…”