Mosquito Q&A

Editor’s note: PCT recently sat down with Nicky Gallagher, technical services manager, professional pest management, Syngenta, to talk about a variety of mosquito control topics, including treatment timing, training technicians and involving customers in the prevention process.

PCT: What species of mosquitoes are most problematic in the U.S.?

Nicky Gallagher: There are approximately 200 species of mosquitoes in the U.S. Prevalent species across the country differ from area to area, as well as season to season. Thus, determining problematic species depends on which species are being a nuisance or transmitting diseases in a given area. For example, I live in central Ohio, where the Asian tiger mosquito has become well-established. If you go to northern counties in Ohio, it’s not nearly as prevalent — but its close relative, the Asian bush mosquito, will drive people indoors.

PCT: How can PMPs train their technicians to know the difference between mosquito species?

NG: Some species have distinct features and can be identified quickly, such as Asian tiger and yellow fever mosquitoes. However, identification can also be a challenge because some species look similar to each other. Using a microscope or magnifying glass can help magnify characteristics that aid in identification, such as scale patterns and the size of the proboscis. Pest management professionals can also look for training and identification workshop opportunities through local universities or the American Mosquito Control Association.

PCT: How do control techniques differ for the different species?

NG: Adult Culex mosquitoes tend to be controlled with ultra-low volume insecticide applications, which are applied while mosquitoes are in flight during late night and early morning hours but don’t provide residual control. These applications are usually conducted by local municipalities in specific area codes. “Backyard” mosquito species should be controlled with barrier treatments, which use a long-lasting residual insecticide that targets mosquito resting sites. Regardless of the species, all control programs should involve an insect growth regulator (IGR), larvicides and other integrated mosquito control measures.

PCT: Do different formulations work better in certain situations? Why?

NG: It depends on the target mosquito’s life stage, species and location. Resting sites treated with a microencapsulated formulation will provide long-lasting control, which is ideal for mosquitoes that rest in vegetation, such as the Asian tiger mosquito. Larvicides come in granular, briquette or liquid formulations, and each type has its own pros and cons. It’s really about what works best for the particular situation.

PCT: How do treatment intervals differ for different mosquito species? And how does the time of year affect treatment schedules?

NG: Treatment intervals can differ depending on factors like how much rain occurs during the active season and how long-lasting the treatment is. A mosquito develops from egg to adult in about seven to 12 days, which is a fairly quick life cycle. Incorporating an IGR into a mosquito control program will help break the life cycle and increase the treatment interval. Using an adulticide with an IGR can help provide protection for up to 60 days.

PCT: What are some of the most common mosquito habitat situations/environments that PMPs will encounter on a residential property? A commercial property?

NG: Container-breeding mosquitoes are quite common on residential properties. As the name implies, they can develop in natural and artificial water-holding containers. Examples of natural containers include tree holes, bromeliad leaf axils and bamboo trunks. Artificial containers can include man-made receptacles like tires, cans, flower pots, bird baths and pet dishes. These kinds of containers can also be found in or around commercial accounts.

Summer floodwaters can produce large number of mosquitoes, such as Aedes vexans, which can fly long distances and readily feed on people throughout the season. Residential and commercial accounts near permanent or semi-permanent water sources, such as marshes or ditches, may be subject to these types of mosquitoes.

PCT: Some mosquitoes are most active at dusk, for example. What’s the best way to approach the timing for these types of treatments?

NG: Although many nuisance mosquitoes feed at dawn and dusk, timing is not as critical for residential mosquito control. Barrier treatments target mosquito resting sites, so as they move from leaf to leaf, or surface to surface, in search of food, they can pick up a lethal insecticide dose. Of course, this depends on the formulations and active ingredients used as part of the application.

PCT: What should a technician do upon arrival at a new account? What are the first steps he/she should do as far as inspection, analysis, discussion with customer, treatment approach, etc.?

NG: Before making any applications, conduct a thorough inspection of the property. Identify and document areas that should be treated and avoided. Customers might also be able to help pinpoint mosquito “hot spots,” which could reveal cryptic breeding sources.

Provide customers with a checklist of conducive areas or conditions that might need attention, such as broken gutters. Be prepared to address any concerns they may have around insecticide safety, pollinator safety and mosquito management expectations.

Many PMPs prefer to use backpack mist-blowers for barrier applications, which are ideal tools for the job. Regardless, proper knowledge about equipment and application techniques can make a large difference in the efficacy of an application.

PCT: How can customers best help with mosquito control? (Turning over toys that collect water, etc.)

NG: Reducing potential breeding sites is a large part of a successful mosquito program, so provide customers with a checklist of helpful things they can do on their own properties. For example, they should empty water-holding containers every seven days. Aedes mosquito eggs can stick to the sides of containers, so customers should also scrub the inside and outside of these containers.

PCT: What’s the number one misconception PMPs have about mosquito control?

NG: Some PMPs may think offering residential mosquito control services is a risky endeavor. However, it’s really a great business opportunity. It doesn’t take a ton of investment in terms of equipment, and with the appropriate education, training and certification, it can be a valuable add-on service. Customers really appreciate the difference it can make in the quality of their lives.

PCT: Is there anything else you’d like to add?

NG: Always stay away from claims of disease prevention when marketing mosquito control programs. For instance, a customer may be bitten by an infected mosquito while visiting another area.