Mosquito Control in Delaware

What mosquito service covers

Mosquito work is a yard program, not a house program. The goal is to make the outdoor space usable during the hours you want to use it, which means reducing the resting adult population and cutting off the water producing the next generation.

The two halves of the job

• Adult reduction: treatment of shaded resting harborage, which is where adults spend most of the day
• Source reduction: locating, emptying, altering or treating the standing water on the property
• Inspection of the usual container sites, which are almost never the ones people expect
• Repeat visits through the season, because adults recolonize from beyond the property line

Delaware has both salt marsh and freshwater mosquitoes, and they behave differently enough that treating for one does not fully address the other. Salt marsh species breed in tidal wetland and can fly considerable distances inland, which is why properties nowhere near a marsh still get pressure from them. Freshwater and container species breed close to home, often within a few yards of the door, and those are the ones a property owner can actually do something about.

How we treat it

We start by walking the yard for water. Corrugated downspout extensions, clogged gutters, tarps, boat covers, plant saucers, wheelbarrows, tire swings, unused kiddie pools, low spots that hold rain for more than a few days, and the corrugated drain pipe running under a driveway are the usual finds. Any of these can produce a generation in about a week in July heat.

Adult treatment goes onto the underside of leaf surfaces, dense shrubs, ivy, fence lines, deck skirting, under decks, and the shaded north side of the structure. That is where adults rest during daylight. Treating open lawn accomplishes very little, and treating flowering plants is avoided so we are not putting material where pollinators forage.

Water that cannot be removed gets a larvicide instead, typically a Bti or growth-regulator product suited to the site. Bti is a bacterial larvicide that acts on mosquito larvae and is used in ornamental ponds, ditches and catch basins where dumping is not an option.

What to expect

Expect a noticeable drop within a day or two of the first treatment, and expect it to be a reduction rather than an absence. A yard next to woods, marsh, a ditch or a neighbor with an untreated pool will always take in mosquitoes from outside. We are managing the population, not eliminating a species from the neighborhood.

Treatments are typically repeated on a roughly three-week cycle through the season, because residual materials break down under sun and rain and because a new generation is always working through. Heavy rain shortly after a treatment can shorten its useful life.

We ask that pets and people stay off treated vegetation until it has dried, which is usually under an hour in summer conditions. Cover or move fish ponds, pet bowls and open food before service, and let us know about a beehive or a vegetable garden so we can work around it.

Delaware mosquito season

The season here generally opens as consistent nighttime temperatures come up in April or May, builds through June, and peaks from July into September when heat and afternoon thunderstorms combine. Activity usually persists into October and closes with the first sustained cold.

Two local patterns matter. First, the Delaware Bay marsh corridor east of Route 1 produces salt marsh mosquitoes in volume after high tides and heavy rain flood the marsh surface, and those broods can reach inland properties in Milford, Frederica, Little Creek and Smyrna. Second, the flat, poorly drained ground and open drainage ditches common through Kent County hold freshwater breeding sites long after a storm has passed.

New construction is its own case. Subdivisions around Middletown and Townsend often carry stormwater management ponds, temporary erosion control basins and fresh grading that ponds water, and that combination can produce a heavy local population in a neighborhood that had none the year before.

What you can do between visits

Source reduction on your own property is the highest-value thing a homeowner can do, and it costs nothing.

• Walk the yard after every rain and tip out anything holding water, down to bottle caps and plant saucers
• Clean gutters and replace corrugated downspout extensions with smooth pipe that drains fully
• Change birdbath and pet water daily, and keep pool and hot tub circulation running
• Store buckets, wheelbarrows, recycling bins and toys upside down
• Repair torn window and door screens, since container species readily come indoors
• Thin dense ground cover and ivy against the house, which is prime daytime resting harborage

Standing water on a neighboring property will limit what any treatment can achieve. A quiet conversation about an unused pool or a boat cover next door is often worth more than another application.

When to call

Call before the season rather than during it. Starting treatment in April or May keeps the first generations from establishing, and the whole season runs easier from there. Starting in August still helps, but you are working against a population that has had months to build.

Also call if mosquito activity has changed sharply on a property that used to be tolerable. That usually means a new water source appeared, and finding it is more useful than treating around it. Mosquitoes and ticks often share the same shaded, humid edge habitat, so the two programs are frequently run together.