How do spray oils labeled for pest control kill or control insect pests?

Spray oils labeled for pest control are effective primarily through the mechanism of suffocation. When these oils are applied to insects, they form a thin film on the insect's body. This film clogs their breathing pores, also known as spiracles, which leads to a reduction in oxygen intake. As a result, the insects are unable to breathe, ultimately leading to their demise.

This method of action is particularly effective against soft-bodied insects, such as aphids, spider mites, and whiteflies, which are more vulnerable to suffocation compared to other types of pests. The oil acts quickly, making it an efficient choice for controlling populations.

While other methods of pest control, like disrupting reproductive cycles or causing dehydration, may also be viable in different contexts, they do not apply to the specific action of spray oils. Similarly, while some repellents may use odors to keep pests away, this is not the primary function of spray oils aimed at direct pest control. The suffocation mechanism is a distinctive and critical feature that characterizes the effectiveness of spray oils in managing insect infestations.