Where do stink bugs overwinter? - briefly
Stink bugs overwinter in protected sites such as wall voids, attics, barns, and under tree bark, where they form tight aggregations. In temperate regions they select warm, sheltered locations to survive the cold months.
Where do stink bugs overwinter? - in detail
Stink bugs enter a dormant state in late summer, forming aggregations that protect them from cold. The physiological shift, known as diapause, is triggered by shortening daylight and declining temperatures, causing insects to seek insulated microhabitats where moisture remains moderate and predators are scarce.
Typical outdoor refuges include:
- Leaf litter and fallen debris on the forest floor
- Crevices beneath loose bark on trees and shrubs
- Gaps in fence posts, stone walls, and garden structures
- Soil cracks and the undersides of mulch layers
- Dense grass clumps or thatch in unmanaged lawns
Indoor environments are also frequently used, especially in temperate regions where external conditions become extreme. Common indoor sites are:
- Attic spaces, particularly near roof rafters or insulation
- Wall cavities and gaps around baseboards
- HVAC ducts and filters that provide stable temperatures
- Light fixtures, ceiling fans, and other concealed cavities
- Unsealed entry points around windows, doors, and utility penetrations
Selection of a shelter depends on several ecological variables:
- Ambient temperature: locations that stay above the lethal threshold for the species are preferred
- Humidity: moderate moisture prevents desiccation while avoiding fungal growth
- Predator avoidance: enclosed spaces reduce exposure to birds, spiders, and parasitic wasps
- Species‑specific habits: the brown marmorated stink bug, for example, favors man‑made structures, whereas the green stink bug more often utilizes natural leaf litter
Understanding these preferences informs control measures. Sealing cracks, reducing indoor clutter, and removing leaf litter near foundations limit available refuges, thereby decreasing winter survival rates and subsequent spring infestations.