Tempo is a popular insecticide used for controlling pests in and around buildings, targeting a wide range of insects that invade homes and structures. As an effective barrier treatment, this product is frequently used on foundations, porches, and fences to manage perimeter pests. Its widespread use and potent nature have raised concerns regarding its potential impact on beneficial insects, particularly bees and other pollinators. Understanding Tempo’s specific mechanism and toxicity profile is paramount to mitigating the risk it poses to these species.
The Chemical Composition and Mechanism of Tempo
The active ingredient in Tempo insecticide is Cyfluthrin, which belongs to a class of chemicals called synthetic pyrethroids. Pyrethroids are synthetic versions of pyrethrins, natural insecticides derived from chrysanthemum flowers, but they are engineered to be more stable and longer-lasting. This chemical composition grants Tempo its speed and efficacy against a broad spectrum of insect pests.
The mechanism of action for Cyfluthrin is neurotoxic, meaning it directly attacks the nervous system of any insect that comes into contact with it. It works by interfering with the voltage-gated sodium channels in the insect’s nerve cells. This prevents the nerve from resetting, leading to continuous, uncontrolled firing of nerve impulses. This overstimulation results in paralysis, commonly known as “knockdown,” followed quickly by the death of the insect. Because this nervous system mechanism is common across nearly all insect species, the product acts indiscriminately, affecting both pests and beneficial insects like bees.
Tempo’s Direct Toxicity to Honey Bees and Other Pollinators
Tempo’s active ingredient is classified as highly toxic to bees, a designation that applies to both honey bees and other pollinators such as bumblebees. The product label itself carries a warning that this pesticide is dangerous to bees when they are exposed to direct treatment or to residues on crops or weeds. This toxicity is generally divided into two categories: acute contact and residual exposure.
Acute contact toxicity refers to the immediate, lethal effect of a bee touching the wet spray or fresh residue during application. If a foraging bee flies into a freshly sprayed area, the high concentration of Cyfluthrin will likely result in immediate death due to the rapid disruption of its nervous system.
Residual toxicity is a significant concern because Cyfluthrin is designed to remain active on surfaces for an extended period, providing long-term pest control. Bees that land on treated surfaces, like structural cracks or non-blooming weeds near a foundation, can pick up a lethal dose of the residue days or weeks after the initial application. Even sub-lethal exposure, where the dose is not immediately fatal, can impair a bee’s ability to navigate and forage effectively, reducing its chances of returning to the colony.
Strategies for Using Tempo While Protecting Bees
Because of the high toxicity to pollinators, users of Tempo must follow specific application strategies focused on minimizing the potential for exposure. The most effective mitigation technique involves strict control over the timing of the application. It is advisable to apply the product late in the evening or at dusk when bees have already returned to their hives and are not actively foraging.
A second, equally important strategy is to limit the application location to non-foraging areas only. Treatment should be restricted to structural elements, such as foundation cracks, window frames, eaves, and the soil immediately adjacent to the building. Under no circumstances should the product be applied directly to any blooming plants, flowers, or weeds in the treatment area, as these are the primary foraging targets for bees.
Users must also ensure that the spray does not drift onto nearby flowering vegetation, which requires avoiding application during windy conditions. By following the label directions precisely and keeping the spray confined to the target structural surfaces, the insecticide can form a protective perimeter barrier without posing a direct hazard to active pollinators. This responsible use is the only way to manage pests with Tempo while protecting local bee populations.