Online Services Government
  • Departments
  • Commissioners Court
  • Elected Officials
  • Courts
  • Justice of the Peace Courts
  • Constables
  • Residents Visitors Business Employment

    Control Methods

    The following is a list of current mosquito control items that Tarrant County may utilize in mosquito control.

    Gambusia affinis- Gambusia, also known as the mosquito fish, are native to many Texas streams and rivers. Their diet consists mainly of mosquito larvae. This makes them great to use for mosquito control purposes because they are natural and sustainable. For private property use, such as stock ponds, fountains, ornamental ponds and horse troughs they may be available at your local bait or pet stores.

    Bti/Bs- Bti’s actually stands for Bacillus thurengensis isrealensis which is a species of soil bacterium that is toxic to mosquito larvae because sugars that they produce holes in the mosquitoes “intestines”. This may be purchased in most hardware stores in the form of donuts or sometimes in pellets. Keep in mind that these substances will only work on mosquito larvae that are still eating.

    Spinosad- spinosad is a pesticide made from modified compounds from another soil bacterium, Sacchropolyspora spinosa. These compounds bind to receptors and disrupt the neurotransmitter acetylcholine, acting to paralyze the insect. In this way it is comparable to organophosphates, but is a very low risk to other wild life and non-target arthropods.

    Novaluron- Novaluron is an insect growth regulator (IGR) meaning that it affects some part of the insect’s growth and development phase. In the case of Novaluron it inhibits chitin synthesis. This is the protein that makes up an arthropods hard outer skin, so it is considered to be safe for a lot of other wildlife, like vertebrates which do not synthesize chitin.

    S-Methoprene- Methoprene is also an IGR that mimics an insect growth hormone known as juvenile hormone. It is the absence of this hormone that allows the insect to enter the metamorphic stage, which is the transitional stage in which an insect becomes an adult. In the constant presence of s-methoprene the insect will never become an adult, therefore never completing its life cycle.

    Oils- oils can be dispersed over the surface of the water to prevent mosquito larvae and pupae from breathing. Mosquito larvae and pupae do not have gills, but must access air through breathing apparati. Since oils do not need to be ingested, this is a good choice to kill later instar larvae and pupae that do not ingest food.

    Pyrethroids- pyrethroids are a class of pesticides that are derived from pyrethrum- a chemical that is naturally occurring in some chrysanthemum flowers. This chemical disrupts the insect nervous system by keeping open nerve-firing sodium channels. In IMM pyrethroids are used in adulticiding (treating for adult mosquitoes) usually with a Ultra Low Volume (ULV) applicator. This means that very little of the pesticide is used to minimize risks to larger beneficial insects.

    Organophosphates- organophosphates are a class of pesticides that disrupt the enzyme acetylcholinesterase which breaks down the neurotransmitter acetocholine. When this neurotransmitter is not broken down, the result is constant muscle excitation therefore paralyzing the insect. Since organophosphates can also affect other animals including humans, they are applied via a ULV as an alternative to pyrethroids if pyrethroid resistance is observed.