Solving the mosquito problem primarily through larval control is the most logical approach of reducing annoyance. This is the only time in the insect's life cycle when it is truly confined, concentrated and most readily controlled.
When standing water cannot be eliminated from the premises, it should be examined each week to determine whether or not larvae are present. Water can be dipped with either a pan or cup. A white utensil is preferred because brown larvae can be seen easily against a white background. Should larvae be present, an insecticide should be applied at once. Some insecticides labeled for control of mosquito larvae are listed in Table 1.
Table 1. Larvicides for Mosquito Breeding Waters (Follow Label Directions and Safety Precautions)
| Insecticide | Formulation | Amount Formulation per Acre | Remarks |
|
Bacillus thuringiensis Berliner var. israelensis (B.t.i.) (Bactimos) (Vectobac) |
10% B 0.2% G |
1 Briquet/100 ft.2 2.5 to 20.0 lb. |
The higher recommended rates must be used in water having high concentrations of organic pollutants and/or abundant algae. This may be due to a lower ingestion of B.t.i. as a result of food source competition from other organisms and organic debris ingested by the larvae. Or it may be due to the removal or alteration of the active ingredient by absorptive binding to suspended particulate matter. Other water quality parameters such as salinity and pH have little, if any, effect on the activity of B.t.i. Water temperature, as it influences larval metabolic activity and thus larval feeding and development, can be a factor in determining the application rate. This larvicide is non-toxic to non-target beneficial organisms. There is a homeowner label of Bactimos 10 percent Briquet known as ³Mosquito Dunks.² (Kills mosquito larvae growing in bird baths, rain barrels, old automobile tires, ponds, ditches, unused swimming pools, tree holes, flower pots, roof gutters or wherever water accumulates.) |
|
Bacillus sphaericus (B.s) (Vectolex CG) |
This is a corncob granule for Culex mosquitos that works well in septic conditions. | ||
|
methoprene (Altosid) |
5% ALL 20% ALL Concentrate 7.9% B 1.8% XR 4.0% P |
0.75 to 1.0 oz. 1 Briquet/100 ft.2 1 Briquet/100 ft.2 2.5 to 10 lb. 3.0 to 4.0 oz. |
This product is an insect growth regulator (IGR), which acts by inducing morphological changes interfering with normal development. These effects are not immediately apparent and result in the failure of adult mosquitoes to emerge from pupae. Apply to 2nd, 3rd and/or 4th instar larvae, not pupae or adults. Treated larvae develop to the pupal stage where they die. |
|
oil* (GB-1111) (Bonide) |
Petroleum distillate |
2 to 5 gal. 1 to 5 gal. |
Use high rate in areas of heavy vegetative cover and in waters high in organic matter. Do not apply to fish hatcheries. |
|
temephos* (Abate) |
44% EC 1% SG 2% BG 5% BG 5% P 5% CCG |
0.5 to 1.5 oz. 5 to 20 lb. 2.5 to 20 lb. 2 to 10 lb. 4 to 10 lb. 2 to 100 lb. (Varies according to tires per acre.) |
Use the high rate in polluted water and areas with organophosphate insecticide-resistant mosquitoes. For tire treatment, apply 1 lb. of 5 percent CCG per 100 square feet of tire pile service area. Do not use on food, forage or pasture crops. Repeat as needed. |
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*To be applied only by licensed, certified pesticide applicators. ALL=Altosid Liquid Larvicide, AS=Aqueous Suspension, B=Briquet, BG=Biodac Granule, CCG=Corn Cob Granular, CG=Celatom Granule, EC=Emulsifiable Concentrate, G=Granule, P=Pellet, SG=Sand Granule, XR=Extended Residual |
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