Downstate and upstate, same spiders, different job
The species list barely changes between Brooklyn and Buffalo. The work does. In the dense downstate housing stock, the limiting factor is access. Buildings sit over shared cellars, utility chases run floor to floor, and a population living below the ground floor can supply every apartment above it. A tenant who cleans corners weekly still gets webs, because the source is behind a locked door. The single most important question there is whether treatment covers common areas. Upstate, around Rochester and Syracuse, more housing is single-family with fieldstone or poured cellars, detached garages, and yards that back onto real vegetation. Access is not the problem; moisture and the long wet autumn are. Here the work is drying the cellar, fitting a bulkhead seal, and clearing webbing from joists. The Hudson Valley and Long Island sit between the two, with older single-family stock and coastal humidity. Before you compare any two quotes in New York, work out which of these situations you are in, because it determines what the scope should even contain.
What is actually in the web
Four spiders account for nearly every indoor sighting in New York, and none of them can hurt you. Cellar spiders are the pale ones with thread-fine legs, hanging inverted in loose messy webbing. They need humidity, so they gather in cellars, boiler rooms, and under sinks. Cobweb spiders build the dusty tangles in ceiling corners that reappear a week after you sweep them. Funnel weavers build flat sheet webs with a tube retreat, usually outside along foundations, in window wells, and across low plantings. Wolf spiders build nothing and hunt on the ground, and they are the large fast one people find on a kitchen floor in September. What none of these do is threaten anybody. The CDC's range for the brown recluse covers the midwestern and southern states, and UC Riverside sets the northeastern boundary at southernmost Ohio. The CDC also describes black widows as concentrated in the southern and western states. Once you know that, every one of these gets the same response: vacuum the web, note where it came in, move on.
The New York year in spiders
April and May start quietly. Overwintered spiders resume activity outdoors, webs reappear in areaways and window wells, and indoor life is unchanged. June through August is the build. Median humidity near 69 percent and steady rain keep gnats, midges, and flies abundant statewide, and spiders grow all summer on that supply. Cellar webbing thickens during these months, which makes this the right window for a dehumidifier and a caulk gun rather than a sprayer. Late August through October is when the phone calls happen. Males wander, sightings jump, and in a large building several tenants report the same thing within a fortnight. November through March, lows near a median 18F shut the outdoor season down completely, more sharply upstate than on Long Island. Heated cellars keep their residents going regardless, so winter webbing is normal rather than alarming. The useful takeaway is timing. Exclusion work done in July prevents the September problem. The same work done in October is cleanup after the fact.
Old buildings and where the openings really are
A median home value around $265,000 across New York's largest cities points at housing that is old by national standards, and old buildings leak in predictable places. At the cellar level: bulkhead doors that no longer seat, areaway grates with no screen, cellar windows with rotted frames, and gaps where water and gas lines pass through the wall. Fieldstone walls cannot be sealed and should not be the target. The realistic goal is closing the boundary between the cellar and the living floors, which means the cellar door, the stair chase, and the plumbing penetrations in the first floor. At the street level: stoop lights that draw insects, ivy climbing the facade, and door bases worn enough to show daylight. Upstate, add the storm window that never quite closes and the attic hatch that has no gasket. None of these fixes is expensive individually. Together they change your September more than any product application, and unlike a treatment they keep working through the following four winters.
What to ask before you agree to anything
Because nothing dangerous is involved, you have the luxury of comparing carefully. Take it. First, scope. Does the quote cover the cellar and common areas or only the finished living space? Is webbing and egg sac removal part of the visit? Is any sealing work included, and which specific openings? In a multi-unit building, is the whole building in or just your line of apartments? Second, method. For spiders, placement into rim joists, sill gaps, and voids is right, and broad interior spraying is not. A company that suggests fogging an occupied New York building should be able to justify it, and usually cannot. Third, moisture. A provider who asks about the cellar humidity before naming a product understands the actual driver here. Fourth, timing and return visits. Ask when they would schedule relative to the fall wander and what brings them back at no charge. Then check the license, get every item written into the scope, and compare documents rather than headline numbers.