Chapter 4 (A) Questions

What are the characteristics of a good mosquito larvicide?

1. It is specific for mosquitoes. 2. It has only a minimal impact on nontarget organisms 3. It can penetrate a dense, vegetative canopy

Name and describe two of the most common and effective forms of mosquito source reduction

1. Sanitation - Removing debris (ex discarded tires) that can act as breeding sites and regularly inspecting other water-filled containers (ex. gutters) to reduce breeding 2. Habitat alteration - Altering wet areas (ex. removing surface waters) so they are no longer attractive breeding sites.

What tactics does the typical IPM program for mosquito control include?

1. Source reduction (ex. sanitation and habitat alteration - managing wet areas) 2. Biocontrol (ex. larvae-eating fish and biorational pesticides) 3. Chemical control (ex. larvicides and adulticides) Exclusion (ex. screening), as a preventive measure, is also important.

What is a barrier treatment?

A barrier treatment is an application of a pesticide in a strip alongside or arounda structure, a portion of a structure, or any object (ex. shrub). A barrier treatment usually leaves residual pesticide on the treated surfaces in order to keep pests from entering into the treated area. In most cases, you will apply barrier treatments as high-volume (low concentration) liquids with hand-held spray equipment.

Why are bats and purple martins NOT effective biocontrol agents for mosquitoes?

Although these animals do eat large numbers of adult mosquitoes, they do not significantly affect mosquito populations.

At what stage in a mosquito larva's life is it best to apply a bacterial toxin larvicide? Why?

Bacterial toxins must be eaten by the larvae. It is best to apply them well before the fourth-instar stage to ensure that they are eaten. This early exposure gives enough contact time to kill the larvae before they can pupate and emerge as adults

Why is public education an important part of mosquito control programs?

Because well-informed members of the public are more likely to know how to reduce or prevent exposure to mosquitoes (and thus to mosquito-borne diseases) Public education also helps people to understand the need for and to accept mosquito control programs. Because of education efforts in the past, people today are more aware of the need for mosquito control. In addition, education can increase professionalism among mosquito control workers. By attending continuing education programs, you can learn to reduce overall pesticide use and risk

When is the best time of day to perform ULV applications in order protect nontarget insects? Why?

Between dusk and shortly after dawn At this time, most beneficial insects are at rest.

Define biocontrol.

Biocontrol is the use of living organisms (ex. parasites and predators) to control pests (ex. mosquitoes)

Which types of mosquito larvicides can you apply at any stage in a larva's life?

Conventional insecticides, chitin synthesis inhibitors, nonpetroleum oils and monomolecular films

Name and describe three basic tactics used to PREVENT public health pests from becoming a problem

Effective techniques include sanitation, habitat alteration, and exclusion Sanitation and habitat alteration strive to create an environment that is uninviting and unfavorable for pests Exclusion tries to block pests from entering specific areas. Together, these tactics can help you prevent a pest problem or reduce the chance that it will develop into a large infestation

Define and describe integrated pest management (IPM)

IPM is an ecological approach to pest control. It is based on the habitat and life cycle of the pest. It combines all of the most appropriate pest control strategies into a unified, site-specific plan. IPM plans may include both nonchemical and chemical management methods. IPM is dedicated to managing causes rather than simply treating symptoms. IPM balances the level of ntrol needed with any associated risks The goal of an IPM program is to reduce pest numbers to an acceptable level in a way that is practical, cost-effective, and safe for people and the environment.

How does impoundment management reduce mosquito numbers?

Impoundment management uses dikes to impound salt marshes. The dikes ser contain water pumped onto the marsh surface from a nearby estuary. This eliminates egg-laying sites for the salt marsh mosquito on the impounded marsh because it deepens the water. Mosquitoes enerally do not breed in deep waters Thus, mosquito numbers drop

What is the difference between rotational impoundment management (RIM) and open marsh water management (OMWM)?

RIM attempts to control mosquitoes by minimally flooding diked marshes during the summer months. The excess water disrupts the breeding cycle of mosquitoes that are present OMWM uses shallow ditches to connect mosquito-producing locations on the marsh surface to deep-water habitats (ex. tidal creeks, ponding areas, and deep ditches). These ditches help to control mosquito broods in two ways: 1. They enable fish to swim from deep areas to shallow, mosquito-breeding areas where they can feed on mosquito rva 2. They can drain the shallow, mosquito breeding areas before the adult mosquitoes emerge

When should you use an adulticide to control mosquitoes?

Reserve adulticides for managing mosquitoes that reach the adult stage in spite of efforts to intervene in the larval stage. You may also need to use adulticides when no larval control tactics were used

How can source-reduction efforts affect the amount of pesticide you apply to control mosquitoes?

Source reduction often lessens or even gets rid of the need for chemical control of mosquito larvae. In addition, these efforts may reduce the need for adulticides in nearby areas

Whenever possible, what life stages should your mosquito control efforts target first?

The immature life stages: eggs, larvae, and pupae

How do chitin synthesis inhibitors work to control mosquito larvae?

These inhibitors disrupt the molting process. Therefore, mosquitoes cannot mature

What are surface treatments? Why are they not common in the United States?

This method uses residual insecticides to kill mosquitoes that later rest on the treated surfaces. Residual treatments are not routinely used in the United States for mosquito control because most residual pesticides in this country (like DDT) have been phased out.

Describe several benefits of ultra low-volume (ULV) application vs. larger droplet application of mosquito adulticides

Using tiny ULV droplets can increase efficiency while decreasing the risk to the environment and to public health. This is because the small droplets drift far beyond the point of release and settle in a widely dispersed manner on the ground By the time these droplets land, their toxicity is often weakened by hydrolysis (reaction with water molecules in the air) However, the small amount of chemical that does remain in each droplet is still lethal to any mosquito that the droplet touches. In addition, tiny ULV droplets are not likely to contact objects larger than mosquitoes. This is because the physical characteristics and size of larger objects cause the droplets to drift around them rather than deposit on them. The very small flying mosquitoes, however, do not ward off the small droplets in this way. Also, use of the fine ULV droplets means that there are millions more droplets to control mosquitoes than there would be if you used larger droplets.

In what situations would a space spray help to control adult mosquitoes?

When you want to treat an enclosed space such as a house, tent, trailer, warehouse

When applied from the ground or by airplane, which type of pesticide is usually more effective and target specific: larvicides or adulticides?

larvicides