The mosquitoes biting you on a Beirut balcony almost certainly hatched within a short flight of it. The species that dominates daytime biting here breeds in containers rather than marshland, so the source is usually your own roof, your balcony or the plot next door.
A spray kills the adults in front of you, while the larvae in the roof tank keep hatching for days afterwards, so a treatment that never went up to the roof buys a quiet week and nothing else.
The season here is long and peaks twice, and the insecticide most people still associate with fogging no longer kills the local population.
The mosquito in front of you, and why it changes the search
Aedes albopictus, the Asian tiger mosquito
It is small and dark, sharply striped on the legs and body, and it bites in daylight rather than only at dusk. The species is established in Lebanon and still gaining ground, and the ECDC map update of June 2025 listed the country among those where it spread further. It breeds in containers, so the water producing it is clean, small and close by. Its range follows the humid western slope from the coast up to roughly 1,000 metres, taking in Beirut, Mount Lebanon, Metn, Baabda and Keserwan. The dry interior, the Bekaa included, sits outside that band.
Culex, the mosquito that waits for the lights to go out
This one is plain brown rather than striped, and it feeds once the light has gone. It breeds in water that has turned stale and organic rather than in a clean tank: blocked drains, sumps, a neglected septic pit. When the biting starts at night, the survey moves off the balcony and down into the drainage.
The Lebanese season is long, and it peaks twice
Mosquito activity here runs from roughly late April into December, about thirty-two weeks. Numbers climb to a first peak in July, ease back through August, then rise again from late September into early October. The autumn peak is the one households are unprepared for, because whatever was applied in June has lost its residual by then.
Stored water is what keeps the numbers up
The collapse of the public water supply, documented by UNICEF, moved Lebanese households onto tanks, drums and jerricans, and that stored water is now the single biggest breeding driver in the country. A tiger mosquito needs roughly a cupful of it to produce a generation. The productive containers repeat from building to building: a roof tank with a split or missing lid, the tray under a split air-conditioning unit, saucers under balcony plants, the bucket kept full under the sink for when the supply cuts, a blocked balcony drain, an uncovered cistern, the folds of a plastic chair cover, and the drum standing on the site next door.
A flat with no standing water of its own can still fill with mosquitoes produced two buildings away, so the survey looks over the parapet.
West Nile virus, kept in proportion
West Nile virus circulation in Lebanon is serologically confirmed in both people and horses, although the realistic outcome of a bite on a balcony is still an itch and a broken night of sleep. The case for dealing with the breeding water does not rest on disease risk anyway.
Who is allowed to treat a home in Lebanon
Household pest control in Lebanon is licensed by the Ministry of Public Health, through the Directorate of Health Prevention and its Sanitary Engineering Service, with the technical conditions set by Decree 5100 of 12 April 1982. Agricultural pesticide work sits under the Ministry of Agriculture, and the two licences are not interchangeable. There is no public register a customer can search, so the only check available is to ask a contractor for the certificate and read which ministry issued it. The rules are set out in this guide to the Lebanese licence system.
The Ministry of Public Health has banned aluminium and zinc phosphide for pest control in residential and populated areas nationwide. No home should be treated with an agricultural fumigant.
Why malathion fogging is the wrong tool here
Malathion no longer works on Lebanese mosquito populations. Testing recorded 25.33% mortality, which is the resistant range, while the same populations were fully susceptible to pyrethroids. Fogging with malathion therefore produces smoke, a smell in the stairwell and a mosquito population that carries on breeding, and any fog reaches only the adults in the air as it passes.
What the treatment actually is
Two products do two different jobs: a larvicide in the water that has to stay, and a residual pyrethroid on the surfaces adults rest on. Tiger mosquitoes spend the gaps between bites in shade and humidity, under leaves, against a shaded wall and in the cool part of a stairwell, and treating those surfaces is what carries on working after the van leaves. Fogging keeps a narrow role as a fast knock-down before an event, on top of source reduction.
How a mosquito visit runs
The order is fixed, because treating adults before finding the water wastes the treatment.
One, the water survey
A technician walks the property with you, roof and tanks first, then balconies, drains, planters, air-conditioning drip lines, the garden and the stairwell, looking for anything that has held water since April. Containers are noted one by one, since the fix differs: a lid, a screen, a drain rod, or tipping it out.
Two, source reduction and larviciding
Where a container can be emptied, covered or drained, you are shown what has to change, since a lid that closes properly outperforms any product. Where the water has to stay, and a roof tank usually does, it is treated with a larvicide so the eggs already in it never reach the air.
Three, residual treatment and the return visit
Resting surfaces are treated with a residual pyrethroid, the part of the job that keeps working between visits. A follow-up belongs to the job from the start, and a property treated in early summer gets its return placed against the late September rise.
What to do before the visit, and after it
Beforehand, do not empty or bleach the roof tank, since what is in it is the evidence, and do not spray a shop-bought insecticide on the balcony, which scatters the resting adults. Access helps more than tidying: the roof door and the stairwell open, the storage room unlocked, pet bowls put away and an aquarium covered.
Afterwards, keep children and pets out of a treated room until the surfaces are dry, then open the windows. Do not wash the treated surfaces down, since that removes the residual. Keep the tank lids closed, tip out saucers and drip trays weekly, and walk the balcony again after the first heavy rain, which refills every container in one night.
Restaurants, hotels and shared buildings
Outdoor seating is where mosquitoes cost money, and the water feeding it is usually part of the fit-out: planters and their saucers, drainage channels under decking, condensate lines from split units, and the bin area at the back. Those same wet points drive fly pressure, so the two surveys are worth running together with fly control.
Inside a kitchen or a warehouse the same logic follows the floor drains, the condensate line above the cold room and the water drum kept for when the mains cut.
In a shared building the roof tanks and the cistern belong to the building rather than to any one flat, so a treated apartment under an untreated tank refills from above. Where building management commissions the work, the roof and common areas are done once for the whole block, tanks included.
Areas covered
GRMC works across Beirut, Mount Lebanon, Metn, Baabda, Keserwan and the surrounding areas: Achrafieh, Hamra, Ras Beirut, Verdun, Badaro, Gemmayzeh, Mar Mikhael, Mazraa and Mathaf inside Beirut, Jdeideh, Jal el Dib, Dbayeh, Antelias, Zalka, Dekwaneh and Sin el Fil across Metn, and Jounieh, Kaslik, Zouk and Adma in Keserwan.
Booking an inspection
Call or message +961 3 265900, or send the details through the booking form. Say where you are, which floor you are on, whether the building has a roof tank, and at what time of day the biting happens, since the hour narrows the species.
