Individual and social heterosis act independently in honey bee (Apis mellifera) colonies.

Heterosis occurs in individuals when genetic diversity, e.g., heterozygosity, increases fitness.

Multiple routes of pesticide exposure for honey bees living near agricultural fields.

Populations of honey bees and other pollinators have declined worldwide in recent years. A variety of stressors have been implicated as potential causes, including agricultural pesticides. Neonicotinoid insecticides, which are widely used and highly toxic to honey bees, have been found in previous analyses of honey bee pollen and comb material.