Common herbicide impairs fertility but not survival in bumblebees, <em>Bombus impatiens</em>

Insect declines have raised concerns over widespread agrochemical usage. Current environmental risk assessments (ERAs) focus on lethal effects, often neglecting fitness-relevant parameters. Our results demonstrate that chronic exposure of male bumblebees to a field-realistic level of a glyphosate-based herbicide significantly enhanced their survival yet reduced living spermatozoa ( 34%). This highlights a physiological shift, where resources appear prioritized toward survival mechanisms over reproductive investment. Such findings underscore critical false negative results in current ERAs and advocate for incorporating reproductive fitness endpoints to better understand and mitigate ongoing insect declines.