In Prince George's County, documented activity runs by season: termite swarms in spring, carpenter bees in April and May, Asian tiger mosquitoes in the warm months and brown marmorated stink bugs from mid-September into fall. Other pests get no month claims here.
Key takeaways
- Spring is the season for termite swarmers and for carpenter bees looking for nest sites in April and May.
- Warm months are when Asian tiger mosquitoes breed in anything that holds rainwater, so the yard is the place to start.
- Brown marmorated stink bugs move toward buildings from mid-September, and sealing gaps before cold weather is the time to act.
- Rats are a year-round issue, and county guidance expects neighbors to act together before the Health Department is called.
- Where the record is silent, this calendar says so. A gap in the sources is not a promise that nothing happens in that month.
What does spring bring to Prince George's County?
Spring brings the two clearest seasonal patterns on this calendar: termite swarmers and carpenter bees. Swarms are reported after warm, rainy weather, and carpenter bees begin looking for nest sites in April and May.
A 2004 newspaper report that quoted state agriculture officials put termite swarms in Maryland at roughly March through June, after warm weather and rain. That report is older than this calendar, so treat the month range as a guide rather than a schedule. A swarm on a warm afternoon is one event, and it says a colony is nearby. It does not say when the next swarm will come.
Carpenter bees are the other spring pattern. The University of Maryland Extension says females look for nest sites in April and May, and they favor bare or weathered wood. The same source says the bees are not aggressive and are pollinators, so the usual advice is to treat them only when they are damaging wood. Paint or stain on exposed boards makes the wood less attractive for nesting.
Spring is also when a homeowner is most likely to walk the perimeter after winter. Look at fascia boards, deck rails and any gaps where wood meets masonry. Note what you see and the date, because a record of when activity started helps a technician decide whether the problem is seasonal or ongoing.
What do the warm months bring?
The warm months are when Asian tiger mosquitoes breed in containers and when the most visible mosquito activity in the state occurs. Source reduction is the first step, because spraying has only a limited effect on this species.
The Maryland Department of Agriculture calls the Asian tiger mosquito the biggest nuisance in the state, and about 60 percent of the mosquito complaints it receives concern this species. These mosquitoes breed in anything that holds rainwater, including toys, tarps, abandoned pools and plastic gutter extensions. Emptying those containers each week is the most useful thing a household can do.
A news report described West Nile-positive mosquitoes found in the Bowie area. The date of that finding was not confirmed here, so it should be read as evidence that the virus has been present in the region rather than as a seasonal count. Nothing on this calendar gives a county-wide mosquito figure, because none was sourced.
Warm months are also when ticks are a concern along wooded and grassy edges. The Maryland Department of Health names the blacklegged, lone star and American dog ticks as the species most likely to bite people in the state. It recommends daily tick checks after time outdoors and EPA-registered repellents. No month range for ticks is claimed on this page.
When do brown marmorated stink bugs move indoors?
Brown marmorated stink bugs fly toward overwintering sites from mid-September into October, and some Maryland Department of Agriculture material runs the window into November. They are a fall problem, and the time to seal gaps is before the first cold snap.
An MDA publication from 2010 describes the flights to overwintering sites as running from mid-September through October. Another MDA document gives October to November. Because the two sources differ, this calendar gives the window as mid-September into fall rather than picking one month. Either way, the insects are looking for shelter for the winter, not food.
Those shelters include the space under siding, behind shutters and in attics. The University of Maryland Extension advises caulking cracks, weather-stripping doors and windows, and removing window air conditioners before the cold weather. Indoors, the insects can be vacuumed or released outside. They do not bite, which is worth knowing before anyone reaches for a spray.
The fall pattern matters for timing the work. Sealing in late August or early September is ahead of the flight, while sealing in December is after the insects have already chosen their spot. A technician can walk the exterior and point out the gaps that matter on a given house.
What stays the same all year?
Rats and general apartment pests are the parts of the calendar that do not follow a season. Prince George's County guidance on rats asks neighbors to act together, and a building with shared walls needs a plan that covers every unit.
The county's rat guidance is a checklist. It says neighbors must work together, and that if a problem persists after all of its steps you contact the county Health Department's Division of Environmental Health, through its Environmental Engineering Program in Largo. The checklist is the place to start, because rats move between yards and a single household's effort often fails when the next lot is left alone. The species involved is not identified on this page, because no local species record was sourced.
Apartment pests are another year-round pattern. Bed bugs and German cockroaches are general problems in multifamily housing, because they move through shared walls, pipes and furniture. No Maryland statistic for either pest is claimed here. The practical point is that treating one unit alone often fails when the neighboring units are left untreated.
Plant pests also run through the year. The spotted lanternfly is under a Maryland Department of Agriculture quarantine across every county in the state, Prince George's County included. It is a plant pest rather than a household pest. Sightings are reported to the department, and businesses moving regulated items need its permit.
Why does the calendar say so little about winter?
Winter gets the least sourced detail on this calendar. That is a gap in the record, not a promise that nothing happens in the cold months, and it is the reason the page does not invent a winter pattern.
The sources used for this calendar describe spring swarms, spring nesting, warm-month mosquitoes and fall insects seeking shelter. They say much less about what happens in December through February. A reader who sees an empty winter should not take that as a sign that pests are absent. It only means the page has no documented pattern to report.
Winter is still the season when inspection pays off. A technician can look at the foundation, the crawl space and the exterior while the vegetation is down, and the findings can be planned for the spring swarm window or the fall shelter-seeking window. Booking an inspection in the cold months gives the spring plan a head start.
If you are not sure which pest you are seeing, describe it to the technician with the date, the location in the house and a photo or sample if you can safely collect one. The calendar helps with timing, but identification comes from the specimen.
How should you use this calendar when planning a visit?
Use the calendar to decide when to inspect and when to act, not to decide whether you have a problem. The seasonal patterns set the timing of the work, and the inspection sets what the work is.
Start with the season you are in and the pests you have actually seen. If you have seen swarmers, the termite inspection is the next step. If you have seen mosquitoes breeding in containers, the first step is a yard walk and a container clean-out. If you have seen rodent activity, the county checklist is the first step before a professional is called in.
Keep a short written record: the date, the place, what was seen and how many. That record is more useful to a technician than a month-by-month guess, and it helps separate a one-time event from a pattern. It also makes a written quote easier to compare, because the visit can be scoped to the activity you recorded.
Call (855) 974-4733 when the record shows activity that repeats or when the pest is inside the home. The line is answered 24/7, so a call during a difficult week does not have to wait for a particular month. A technician will confirm the scope on site before any work begins.
Where do the seasonal patterns overlap?
Several sourced patterns overlap in spring and in the fall, and the overlap is the reason a single calendar entry is not enough. Wood-nesting insects and swarming termites share the spring, and shelter-seeking insects share the fall with household routines that change as the weather turns.
In spring, the two wood-related patterns can look alike to a homeowner. Carpenter bees drill round holes into bare or weathered boards, often on fascia, decks and window trim, and termite swarmers can emerge near the same boards. The difference is that carpenter bee activity is a hole in the wood, while a termite problem often shows up as soft wood, mud tubes or wings near a window. Looking at the damage, not only the insect, helps sort the two.
In fall, the stink bug window overlaps with the time when households start heating and closing the house. A gap that let a few insects in during warm weather can become a daily issue once the house is sealed for the season and the indoor air is warm. The practical result is that sealing and inspection are best done before the house closes up, not after the first insects appear.
Rats and mosquitoes overlap in the warm months in the sense that both are drawn to the same yard features: trash, standing water and dense planting. A yard walk that deals with containers also reduces some of the shelter rats use, so the two jobs share a checklist even though they are separate pests.
Frequently asked questions
When should I call about rats?
The county guidance asks neighbors to work through its checklist together first. If a problem persists after all of its steps, the county says to contact the Health Department's Division of Environmental Health. Calling (855) 974-4733 is also an option if you want a technician to look at the property.
Is spring the only time termites matter?
No. Spring is when swarmers are reported, but termite damage develops whether or not a swarm is seen. A swarm is a sign to inspect, not a measure of how much damage exists.
Does the calendar change for an apartment?
The seasons are the same, but a shared building changes the plan. Treatments in one unit can be undone by activity in the next, so the calendar works best when neighboring units or the building manager are part of the plan from the start.
Why are some pests missing from the calendar?
Only pests with a documented Maryland or Prince George's County pattern get a month here. For the rest, the page uses plain seasons, and a technician can give timing advice for a specific pest after seeing it.
Sources
- University of Maryland Extension, termites
- University of Maryland Extension, structural pests
- Maryland Department of Agriculture, brown marmorated stink bug control options
- Maryland Department of Health, ticks
- Prince George's County, Rat Problem Checklist
- Maryland Department of Agriculture, spotted lanternfly quarantines
This guide is general information for Prince George's County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.