YARD SURVEY · ONE FLASHLIGHT, TEN MINUTES
Your yard is full of mosquitoes because of twelve containers.
Aedes hatch within a hundred meters of where they bite. This page is the checklist: the twelve in catch-rate order, the weekly rhythm, what works at each life-cycle stage. For the walk itself, stop by stop with a manual image each, the field walkthrough is its own page.
The twelve, ranked by catch rate
Ordered by how often each class turns up positive in CDC container-surveillance rounds.
| SITE | RISK | WHY | ACTION |
|---|---|---|---|
| Plant pot saucers | HIGH | Eggs glued to walls survive months dry | Scrub weekly |
| Open buckets, watering cans | HIGH | One bucket seeds a street | Tip & store dry |
| Clogged roof gutters | HIGH | Hidden organic water, Culex at night | Flush |
| Folded tarps, pool covers | HIGH | Each fold is a puddle | Shake weekly |
| Birdbaths | MED | Safe with a flush rhythm | Refresh every 5 days |
| Children's toys | MED | Sandboxes, trucks, slides all pool | Drain or indoors |
| Trash bins, lids | MED | Lid rims hold rain | Drill drain holes |
| Pet bowls | MED | Warm, organic, refreshed daily | Rinse daily |
| Rain barrels | MED | Cannot tip; treat instead | Screen + Bti |
| AC drip pans | LOW | Constant trickle in season | Check weekly |
| Tree holes, stumps | LOW | Natural containers | Fill with sand |
| Property line | LOW | Drainage crosses fences | Fix your side |
PLATE 002
- Granules: one handful per barrel, per label
- Mesh lid: adults kept out, rain let in
- Briquette on rim: the 30-day form
THE QUESTION PEOPLE ACTUALLY TYPE
How long until mosquitoes breed in standing water? About seven to ten days at summer water temperatures. Empty, scrub or tip the container within that window and the eggs glued to the wall die with it.
WHO dengue guidelines (2009), ch. 2, checked 2026-09
What works at each stage of the week
Interventions map onto life-cycle stages. Match the tool to the day, not the advertisement.
Tip and scrub
Physical removal. Zero cost, zero chemical. The wall scrub destroys glued eggs.
Bti for water you keep
Rain barrels and fountains: a Bti dunk kills larvae, harmless to pets and birds. The one product class we grade.
Nothing works
Pupae do not feed. No tablet, no oil, no gadget reaches them. This is why the window matters.
Repellent on skin, not candles
Registered actives on people, nets on beds. Yard sprays are last, not first.
Risk ranking: CDC container-surveillance guidance and WHO dengue vector surveys. Development window: WHO dengue guidelines (2009) ch. 2. All citations
The weekly rhythm, aligned with rain
The twelve-site list is what to look at. This is when.
Saucers, buckets, gutters, tarps. Ten minutes while the water is still visible.
Same day each week so the walk survives a busy calendar.
Bti in barrels, mesh on openings, AC drip line still going to soil.
Pet bowls and condensate refill without rain. The dry week is when those two are missed.