Which type of pesticide would be least likely used in aerial applications?

Rodenticides would be least likely used in aerial applications because they are typically intended for use in specific environments where rodent control is necessary, such as agricultural fields, warehouses, or buildings. The application of rodenticides often requires targeting localized areas to ensure effectiveness and minimize the risk of non-target exposure, which is difficult to manage with aerial spraying.

In contrast, insecticides, fungicides, and herbicides are commonly applied via aerial methods since these substances often need to cover larger areas and can be distributed more effectively from above. Aerial applications are particularly beneficial for controlling pests and diseases over extensive agricultural fields, making insecticides, fungicides, and herbicides more suitable for this method of application. Therefore, rodenticides, which demand precise placement and limited distribution, are understandably less suited for aerial application techniques.