Trap Tips

Mosquito Control Supplement - Mosquito Control Supplement

Different types of mosquito traps are designed to do different things. Here’s a review of different ways to use them and the benefits of mosquito traps.

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Pest management companies continue to add mosquito services to their offerings and with good results. There are several aspects to a good Integrated Mosquito Management (IMM) program, one of which is the use of traps. This article will focus on how traps can be used in a mosquito service, what the benefits are and what factors to consider when choosing traps.

There are many kinds of mosquito traps on the market these days and they are designed to do different things. This is a key point. And although they may appear to be simple devices, the science behind them can be sophisticated.

The vast majority of traps attract and capture either 1) host-seeking female mosquitoes, i.e., those seeking a blood meal in order to produce eggs, or 2) gravid female mosquitoes, i.e., those looking for a standing water source in which to lay eggs (hence referred to as “gravid traps”). The former is a favorite of mosquito abatement districts and other government entities that, among other things, are tasked with performing surveillance for mosquito-transmitted diseases. The mosquitoes are captured alive and can then be tested, primarily for viruses such as West Nile, Zika and several others.

Conversely, a PMP mosquito service is focused on mosquito control and nuisance reduction, not pathogen/disease detection, so these types of traps may not be the trap of choice but they do offer some value to a service and customers in certain situations.

The Autocidal Gravid Ovitrap (AGO) was developed during the course of research by the U.S. Centers for Disease Control and Prevention. It is pesticide-free and attracts egg-laying (gravid) female mosquitoes, which enter the trap through the top and get stuck on a glueboard. For each female trapped and killed, up to 1,200 additional mosquitoes won’t be produced.

USES & BENEFITS. As mentioned previously, different types of traps are designed to do different things. You may decide to use one type of trap or multiple types. Whatever your decision, be sure to consult ahead of time with your technical team, distributor, sales representative or manufacturer to ensure that your needs, and the needs of your customers, will be met. Now let’s take a look at some of the uses and benefits of mosquito traps.

Pre-Service Surveillance and Population Assessment. Prior to beginning any treatments, traps can be run for a few nights to simply get an idea of the size of the mosquito population. Mosquitoes are not distributed randomly on a customer’s property and there may be certain “hot spots” on which to focus your treatments. Traps will help identify these. This technique is particularly valuable for large residential properties or commercial accounts such as golf courses, apartment complexes, large medical facilities, homeowners’ associations, etc. The host-seeking traps mentioned earlier are ideal for this but the gravid traps, which are usually less expensive, also may be used.

Identification of Mosquito Species. As with any pest issue, a thorough inspection and correct identification of the pests are critical to treatment success. A customer is likely to have more than one kind of mosquito bothering them. Different mosquito species have different aspects of their biology that impact our ability to control them. Examples include flight range (anywhere from roughly 100 yards to about 40 miles); type of water they breed in (from fairly clean water in artificial containers to water with high organic content to salt water); and what time of day they feed (most species feed around dusk and early evening while others, such as the voracious Asian tiger mosquito, feed primarily during the day).

You don’t need to be a mosquito specialist to recognize the main differences between the big three mosquito groups: Culex, Anopheles and Aedes. If you are lucky enough to have access to a technical specialist, you can get some good training. Another good resource is extension entomologists, which many universities have. They would be happy to help you with mosquito identification.

Service Evaluation. How do you evaluate your mosquito service? If you wait until customers call to complain, I believe that is too late. After you begin your service, occasional trapping for one to two days can give you a good idea of success.

Indicator of Missed Breeding Sites. Adults of the backyard container-breeding mosquitoes, such as the Asian tiger mosquito and the yellow fever mosquito, usually will only fly approximately 100-150 yards from the breeding site that produced them. Often, it is much less than this. In this situation, if you are catching females in a gravid trap (the type that attracts egg-laying mosquitoes), it may indicate that you have overlooked one or more breeding sites on that particular property. If you suspect that the mosquitoes in your customer’s yard may be breeding next door, take the opportunity to knock on the neighbor’s door and offer your service.

Mosquito Population Reduction. So far, we have talked mostly about traps being used for monitoring and surveillance. However, they also can be very effective in reducing mosquito populations, particularly for certain species such as the backyard container breeders. The traps of choice here are usually the gravid traps. Some of them actually trap and kill the female as she attempts to lay her eggs. Others contaminate the egg-laying female with minute quantities of two insecticides, one of which she disperses to other breeding sites, killing larvae and the second which kills her after a few days.

Note that on average, a female mosquito may lay between 150-200 eggs after each blood meal and under optimum conditions, she could do this six to eight times during her lifespan. So, the math says that trapping and killing just one female mosquito could result in 1,200 to 1,600 mosquitoes never seeing the light of day!

The Autocidal Gravid Ovitrap (AGO) is especially effective against the mosquitoes that transmit viruses such as dengue, Zika, chikungunya, yellow fever and West Nile virus.

SELECTING A TRAP. So, how do you go about selecting a type of trap (or traps) to use in your service? It is worth repeating that you should consult with your technical specialist, distributor, sales representative or manufacturer to make sure your selection fits the company’s service goals as well as the needs of your customers. Key factors to consider include:

Use Patterns. Some traps are best for use in large commercial and urban mosquito control programs, while others work well in smaller residential or commercial settings.

Target Species. A few types are effective against almost all species but most target specific kinds. As an example, gravid traps are particularly useful against the backyard container breeders and some species of Culex mosquitoes.

Attractants Used. All mosquito traps use some type of attractant, whether for host-seeking mosquitoes or egg-laying ones. The range of attractants is quite variable. Some of them are included in the price of the trap, others are purchased separately, and still others represent a minor investment of time and inexpensive materials. One of the most common attractants is carbon dioxide, either in gas form or as dry ice. Other types of attractants include UV light, specific lures and “seasoned” water designed to attract egg-laying females.

Killing Mechanism. As mentioned earlier, many types of traps catch mosquitoes alive so that they can be identified, possibly tested for virus or evaluated for insecticide resistance. Some traps use glueboards to capture and kill; these are pesticide-free and great for sensitive accounts. Other types use pesticides in various ways to accomplish the job.

Energy Requirements. Many types of traps have no energy requirements whatsoever while others require batteries or a plug-in power source. If you use traps that require an energy source, remember to consider this extra cost when pricing your service.

Cost. This varies widely, ranging from approximately $20 per trap to more than $1,000. Most of the mosquito traps that would be considered for use by pest management professionals are not the more expensive ones. Consult with your distributors and suppliers on trap availability and pricing.

SUMMARY. The use of mosquito traps as part of an Integrated Mosquito Management service is becoming more popular in our industry. And, as the demand for mosquito control services continues to grow, so will the need for more diverse, effective tools. As you ramp up for the mosquito season, remember that using traps can save you time and money, as well as make you money. They also can help reduce the environmental impact by eliminating excessive or even unnecessary pesticide applications.

Author’s note: I thank Gene White, B.C.E., global director of vector management, Rentokil, for his contributions to this article.

The author is vice president, technical products and services, AP&G; Captain (retired), U.S. Navy; and past president, American Mosquito Control Association.