Insecticides for Mosquito Control in Maryland

Updated 2014 Recommendations


To serve the citizens of Maryland, the Maryland Department of Agriculture annually reviews the insecticides available for mosquito control. The recommended insecticides are selected from the list of products registered by the U. S. Environmental Protection Agency (EPA) for mosquito control use. The Department of Agriculture bases its selection on experience and research and includes factors of risk, economy and effectiveness under Maryland conditions. The Department promotes integrated pest management of mosquitoes and advocates alternatives to insecticide application when possible. These alternatives include water management, biological control and public education.

When alternative controls are not possible to utilize or are not effective in reducing the mosquito population below a level that may cause unacceptable annoyance or constitute a public health threat, the use of insecticide is an approved option as part of an integrated pest management program.

Insecticides which control mosquito larvae generally have a narrower range of impact to nontarget species and can be applied in a more site-specific manner than mosquito adulticides. Larvicides are, therefore, preferred over adulticides. However, if larviciding is not possible due to weather conditions, logistical problems (area too large, too remote), or larvae are in a prohibited/restricted area (wildlife refuge, national park, military reservation), adult mosquito control is a valid option, and may be the only control option.

All of the insecticides listed below are classified by EPA as general use pesticides with the exception of Trumpet EC which is only used for aerial spraying.

Mosquito Control Larvicides

The following are guidelines for mosquito larvae control in various habitats. A direct application of any insecticide to water in Maryland requires a permit from the Maryland Department of the Environment.

The following nonresidual products are recommended for general use in mosquito larvae habitats in Maryland, including freshwater marshes, salt marshes, woodland pools, ditches and dredged spoil disposal areas:

  1. Altosid Liquid Larvicide - active ingredient - methoprene
  2. Altosid Liquid Larvicide Concentrate - active ingredient - methoprene 
  3. Natular - active ingredient - spinosa - Saccharopolyspora spinosa
  4. Vectobac or Aquabac - active ingredient - Bacillus thuringiensis israelensis

Vectolex is a biological pesticide with the active ingredient Bacillus sphaericus. It displays limited residual activity. Vectolex is recommended for control of Culex mosquito larvae. Vectolex has a low activity against other genera of mosquitoes and is not recommended for control of Aedes, Psorphora, Anopheles, etc.

The residual products listed below have restrictions imposed by the Maryland Department of the Environment prohibiting their use in water inhabited by fish. Use of these products is acceptable in other mosquito breeding habitats:

  1. Altosid Briquets - active ingredient - methoprene
  2. Altosid XR Briquets - active ingredient - methoprene
  3. Altosid Pellets - active ingredient - methoprene
  4. Altosid XR Granules - active ingredient - methoprene

Mosquito Control Adulticides

Type of Application

Aerial ULV 1. Trumpet - active ingredient = naled - applied at 0.05 to 0.10 lb. a.i. per acre
Ground ULV 1.  Permanaone 30-30
2. PermaSease 30-30
diluted in mineral oil - active ingredients = Permethrin and piperonyl butoxide - applied at approximately 0.0031 lb. a.i. per acre.
​Barrier Treatment ​2. Talstar P Professional - Active ingredient = Bifenthrin


Product Labels and Material Safety Data Sheets​

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