Common Summer Pests in the Charleston Area

Summer is the highest-pressure pest season in the Charleston area, and it runs from June through September. The combination of high humidity, frequent rain, and temperatures consistently above 85°F creates optimal conditions for nearly every pest species on the list. Here is what peaks when and why.

June: Formosan termite swarmers and mosquito buildup

Late May through June is Formosan termite swarmer season, and the Lowcountry's large established Formosan population means swarmer events at outdoor lights are common on warm, humid evenings. This is not a reason to panic about swarmers you see at a neighbor's light — swarmers found far from the nest rarely indicate a new infestation. Swarmers found indoors, at your windows, or in large numbers immediately adjacent to your foundation require an inspection.

June is also when Asian tiger mosquito populations begin their summer peak. Any standing water source that has been accumulating since spring is now a productive breeding site.

July: peak mosquito and tick nymph season

July brings the highest Asian tiger mosquito density of the year. Nymph-stage lone star ticks — small enough to be missed on a quick tick check — are at peak activity in July. Yellowjacket colonies are approaching their summer peak and become noticeably more defensive than in spring.

August: stinging insects and roof rat movement

Late August through September is the most hazardous period for yellowjackets. Colony size is at or near maximum, and the late-season resource scavenging behavior — yellowjackets around outdoor food, garbage, and outdoor dining — increases human contact. Roof rat populations begin moving toward structures in late August as temperatures start their slow decline.

Year-round in summer: German cockroaches and ghost ants

German cockroaches and ghost ants do not peak in summer — they are active year-round indoors at stable interior temperatures. But summer's high humidity accelerates ghost ant colony expansion outdoors, and the higher rate of door and window opening in early summer before full AC use creates more interior entry events.