Seasonal record
The Northwest Pennsylvania pest calendar
Lake Erie writes this calendar. Lake-effect cold makes autumn exclusion and winter rodents the twin hinges of the year; the lake's moderated spring delays swarm season slightly behind the rest of Pennsylvania; and a humid summer off the water keeps wasps, fleas, and basement moisture pests busy. A national calendar will mislead you by a month in both directions.
| Month | What is active in Erie County | What to do |
|---|---|---|
| January | Deep winter. Cluster flies and lady beetles wander out of voids on mild, sunny days; house mice are settled in walls and at their loudest at night. | Vacuum wanderers, keep traps checked on mouse runs, and note which windows the flies use — those casings get sealed in spring. |
| February | Still winter indoors. Bed bugs do not observe a season. Stored-product moths can appear around pet food bought in bulk. | Inspect the bed and couch seams monthly in rental units; rotate and check bulk dry goods and bird seed. |
| March | The first warm spell can trigger termite swarmers — dark, four equal wings, shed in piles by windows — and carpenter ants begin moving. | Keep a swarmer specimen in a jar for identification; walk the basement looking for mud tubes on the foundation. |
| April | Termite and carpenter ant season in earnest. Odorous house ants start trailing. Blacklegged tick adults are active in leaf litter. | Identify any swarmer before paying for anything; start tick checks after yard work; place ant bait, not spray, on trails. |
| May | Paper wasp queens found nests under eaves. Blacklegged tick nymphs — poppy-seed sized, the main Lyme risk — peak from now into July. Carpenter ant swarmers fly on warm evenings. | Tick checks and hot dryer for field clothes; watch eaves weekly so a wasp nest over a doorway is found while it is small. |
| June | The first yellowjacket workers are emerging and taking over foraging while the queen stays in the nest laying; nests are still small. Fleas begin in earnest on pets. Mosquitoes breed in any standing water around the house. | Empty standing water weekly; start the veterinary flea program before you see a flea, not after. |
| July | Wasps, mosquitoes, and fleas at full strength. American roaches active in damp basements. Pantry moths peak in warm kitchens. | Fix basement moisture; check under sinks; keep an eye on any steady wasp traffic at one hole in the siding. |
| August | Yellowjacket colonies turn large and defensive, and scavenge sweet food outdoors. Stink bugs begin staging. Flea populations peak indoors. | Never seal a wasp entrance; cover sweet drinks outside; if a nest must go, this is professional work. |
| September | The invasion staging begins: stink bugs, lady beetles, boxelder bugs, and cluster flies gather on warm walls. Rodents prospect for winter quarters. | This is the sealing month — caulk, sweeps, screens, soffits — while the invaders are still outside. |
| October | Peak overwintering invasion, and rodents move in at first frost. Adult blacklegged ticks are active again in the woods edge. | Finish exclusion; set snap traps where droppings appear; tick checks after leaf work and hunting. |
| November | Late invaders settle into voids. Mice are indoors. Clothes moth damage is found as winter wool comes out of storage. | Inspect stored wool before wearing or re-storing; launder, then store sealed. Keep mouse traps running. |
| December | Indoor winter: rodents, cluster flies on bright days, silverfish in the damp basement, and bed bugs travelling with holiday guests and luggage. | Inspect luggage away from the bed after travel; hot-wash and hot-dry travel textiles; keep the basement dry. |
The year in four movements
Spring is for identification. Swarmers over a basement window in April are either a termite colony announcing itself or carpenter ants — two insects, two budgets, one jar with a specimen in it to tell them apart. Spring is also when the desk insists on tick discipline starting before the nymph peak, not after the first bite.
Summer is for water and wasps. Almost every summer pest on the desk is either breeding in standing water, feeding in a damp basement, or defending a nest that grew quietly since June. Find the nest small, fix the water early, and August stays ordinary.
Autumn is for sealing. No month repays an hour with a caulk gun like October. The invaders gathering on the south wall are advertising the exact gaps they intend to use; the rodents at first frost are following runs that a door sweep and a handful of copper mesh can close.
Winter is for the inside of the house. The pests of winter are the ones already in — rodents in the voids, silverfish in the damp, bed bugs in the seams — plus the overwinterers who wander out on bright days to remind you which windows to seal in spring. Winter work is traps, drying, inspection, and notes for the sealing season.