Which of the following formulations is most hazardous to bees?

The formulation that is most hazardous to bees is Malathion Dust. Dust formulations can pose a significant risk to bees due to their physical properties. When dust is applied, it can remain airborne and settle on flowering plants, where bees are likely to forage. The fine particles can be easily inhaled by bees or can adhere to their bodies, leading to exposure even if the direct contact with the pesticide is minimal.

In contrast, other formulations like wettable powders, emulsifiable concentrates, and granules generally have different applications and physical characteristics that may limit their exposure to bees. For instance, wettable powders must be mixed with water and are often less likely to drift into areas frequented by bees after application. Emulsifiable concentrates also often require dilution and may not be as readily airborne as dust. Granules typically need moisture to activate and dissolve, lowering their immediate risk to bees. Therefore, the dust formulation is particularly concerning in terms of insect exposure and potential harm.