Mosquitoes
Culicidae
They damage nothing you grow and can make a garden unusable. The whole answer is standing water: find every container, and tip it out weekly.
How to know it
A slender fly 5–7 mm long with long legs, narrow scaled wings and a long piercing proboscis, resting at an angle on a wall or hovering at dusk. The larvae are the ones to know: comma-shaped wrigglers hanging head-down from the surface film of any still water, diving when a shadow passes.
What you'll see
- Being bitten in the garden at dusk, or in shade during the day where the tiger mosquito is established.
- Wrigglers in a water butt, a saucer under a pot, a blocked gutter, a birdbath or a wheelbarrow left out.
- Numbers climbing four or five days after rain, which is how long the cycle takes.
- Adults resting in dense shrubbery, tall grass and under decking during the day.
- Worst at the shaded, damp end of the garden and around the water feature.
Where it comes from
Everything happens in standing water and it happens fast. Eggs are laid on or beside still water and the larvae develop through to adults in as little as a week in warm weather. A bottle cap of water is enough for the Asian tiger mosquito. Adults rest in cool, humid, shady vegetation and feed at dawn and dusk, or all day in shade for some species.
Warm weather and any standing water within a hundred meters. Container water — saucers, gutters, tarpaulins, tires, toys, bird baths, drain covers — produces the overwhelming majority of the mosquitoes in a suburban garden.
Dealing with it
- Tip out every container of standing water once a week. Nothing else you can do comes close to this.
- Scrub the sides when you empty a birdbath or a saucer; tiger mosquito eggs stick to the container above the waterline and survive drying.
- Drop a Bti briquette or dunk into a water butt, pond margin or anything that cannot be emptied; it kills the larvae and harms nothing else.
- Fit a fine mesh lid to the water butt and keep the gutters clear.
- Move air. A simple oscillating fan on a patio is remarkably effective and needs no chemistry.
Keeping it out
- Walk the garden weekly looking for water — saucers, tarpaulins, buckets, wheelbarrows, tires, corrugated sheets, tree holes and blocked drains.
- Stock a garden pond with fish, or keep the margins planted and moving; a healthy pond with predators produces very few mosquitoes.
- Keep gutters and drains flowing.
- Thin dense damp shrubbery where the adults shelter through the day.
- Welcome dragonflies, bats, swallows and frogs, and never fog the garden with insecticide, which kills all of those and the mosquitoes are back in a week.
What it goes for
No plants. Another entry here for the gardener rather than the garden.
Who hunts it for you
- BatsChiroptera A single bat takes hundreds of moths and mosquitoes in a night, and the moths are the parents of your cutworms, corn earworms and hornworms. Put up a bat box on a warm south wall, leave a night-scented corner unlit, and never spray after dark. Grow to recruit it: Evening Primrose,Honeysuckle,Nicotiana,Summer Jasmine
- Dragonflies & damselfliesOdonata Aerial hunters that take mosquitoes, midges and small flies on the wing all day, and whose larvae spend a year or more clearing the same insects from the water. A pond with planted margins and no fish is the way to have them. Grow to recruit it: Bulrush,Iris,Nymphaea,Pickerel Weed
- Garden birdsPasseriformes Both things are true: birds strip your currants and a brood of blue tits takes several thousand caterpillars out of one fruit tree in a fortnight. Net what you must and welcome them everywhere else — a nest box near the apples is worth more than a spray. Grow to recruit it: Echinacea,Elderberry,English holly,Goldenrod,Rudbeckia,Sunflower
- SpidersAraneae Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense. Grow to recruit it: Lavender,Thyme
See also
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com