The City of Merritt’s Mosquito Control Program is contracted out to a qualified third party, which conducts ongoing larval surveillance and control of specified treatment areas within the boundaries of the City of Merritt. Monitoring and control work usually starts around mid-April and continues through fall. The contractor provides the City with monthly updates (June 2024 update).
SURVEILLANCE: Mosquito seasons are weather dependent. The contractor conducts regular and ongoing environmental and mosquito surveillance, from monitoring snowpack, water levels, and standing water habitats (including tire ruts & depressions) to regular sampling of larval development at all identified sites.
CONTROL: The foremost control method of choice is a larvicide application to eliminate breeding and reduce the risks of mosquito-carrying illnesses. While ground applications will be used, it is understood that some aerial applications to river-level-influenced swamps, sloughs and low-lying fields may be required.
There are several larval mosquito habitat locations within the Merritt region. Most of these areas include swamps, marshes, and wetlands along the Nicola and Coldwater rivers, which converge at the west end of City limits. The Thompson-Nicola Regional District also has its own Mosquito Control Program.
Public Education
Tips for backyard enjoyment when you just do not know where the mosquitos are coming from
Mosquito Magnet/trap – uses CO2 as a mosquito attractant, mosquitos are collected into a bag/box for disposal. Works best on large properties where you can place trap 100ft from sitting area. The trap that has a mesh bag works best. Traps with sticky tape are not as effective.
Mosquito Coils – when started 1 hour before going outdoors, make a difference. They will control adult mosquitos. Citronella candles/torches are only a repellent.
Mosquitos do not like rain or wind: Oscilating fan and/or Cobra Mistand placed by sitting area help mosquito’s not come around entertaining area. FAN + MISTER together = few mosquitos. Mosquitos do not fly well in heavy mist/fog.
Reduce the Risk
Personal Protection is your best defense
Mosquitoes need standing water to lay their eggs.
The best way to keep mosquitoes away is to clean up any standing water sources.
-
Eaves and drains: clean out gutters of debris
-
Buckets, flower pots, plastic containers: drill holes In bottoms or store inside
-
Tires: empty of water frequently; move to a shed or garage If possible
-
Ornamental ponds: a pond aerator will keep water moving; stock with fish to control larvae.
-
Rain barrels: cover lightly with mosquito-proof mesh
-
Change water every 3-4 days in bird baths, pet bowls. plant saucers, children’s wading pools (turn over when not In use)
-
Clean and chlorinate outdoor pools and hot tub
-
Routinely check items that collect water such as buckets, pool covers, tarps, and wheelbarrows.
-
Fill in low depressions in lawn and check flat roofs
-
Rural properties: check for mosquito larvae in lagoons, dugouts and standing water sites
-
Environmentally friendly larvicides for use in fish ponds, ditches and lagoons are available at most gardening and hardware stores.
-
Modifications or treatments of ditches, swamps, streams, lakes and other water bodies that are not man-made and self-contained must be authorized by the Ministry of Water, Land and Air Protection.
Personal Protection
-
Avoid going outside at dawn and dusk. Mosquitoes are most active at these times
-
Wear light coloured, loose fitting clothes with long sleeves and pants when possible
-
Check window screens for holes and make sure they fit snugly into window frames.
If you don’t have screens, keep windows and doors closed when mosquitoes are active -
Use mosquito nets around your home, especially when mosquito populations are high
-
Apply DEET-based mosquito repellent (follow label precautions and do not use on children under six months of age). Note: do not use combination repellent/sunscreen
-
Mosquito ‘zappers’ that attract bugs have not been proven effective.
Mosquito Life Cycle
Mosquitoes belong to one of the largest insect orders, the Diptera (true flies). Within this order are 67 families, mosquitoes belong to the Culicidae family. There are four genera that are of particular interest within British Columbia and Yukon due to their disposition to bite humans and animals. These include Aedes, Anopheles, Culex and Culiseta.
Mosquitoes go through four distinct stages of development during their life: egg, larvae, pupa and adult. Eggs of some species can remain dormant for upwards of 25 years before hatching. Larvae hatch in ponds, catch basins, puddles and other stagnant bodies of water during spring and summer. At this stage of their lifecycle, larvae go through four phases of growth (1st instar to the fully grown 4th instar) moulting their skins as they grow. After a voracious feeding on plant material the larvae quickly develop into pupae from which the adult emerges at the surface of the water. The females then go in search of a blood meal to complete egg development.
Mosquito Larvae
Species of Aedes are abundant from mid May to early August. Their numbers slowly drop as they die off in the fall, after laying their eggs. Eggs are laid in ground crevices and low growing vegetation in areas that are flooded in the spring such as river flood plains and water-holding containers. Larvae must develop in water! They do not hatch and grow in fields of long moist grass. The eggs of some Aedes species will only hatch after a period of drying and chilling, while some eggs only produce larvae after the second or third summer. The first larvae of Aedes can usually be found in late March to mid April. Most Aedes species produce only one generation a year, but late hatching larvae can be found until late June or early July.
Females of Anopheles, Culex and most species of Culiseta hibernate between November and March. Some of the Culiseta are known as snow mosquitoes because the females often emerge from hibernation on warm days when snow is still on the ground. Mosquitoes that hibernate do not bite since they took their blood meal prior to hibernation. These mosquitoes usually die a few weeks after they emerge and lay their eggs.The eggs of Anopheles, Culex and Culiseta are laid on the surface of water. Anopheles lay their eggs singly, Culex and Culiseta lay their eggs in rafts. These eggs hatch within a few days. Larvae usually appear in early April. Eggs, larvae and pupae can be found throughout the summer because most species of these genera can produce several generations in one season.