TNK Blog

We’re in the news!

The most recent edition of Wing Beats, a publication of the Florida Mosquito Control Association, featured a story about the dengue situation in Key West and the deployment of our Trap-N-Kill traps.  Read that article here.  The story starts on page 6.

Stay tuned – more news to come.

I know I promised pictures and updates from the field, but between the long days and the vast amount of data collected, there has been too much to process to get back to posting. So, here goes a summary of the last two weeks.

Logistically, the re-strip process (replacing old strips with new ones, and performing other maintenance on the traps as needed) went fantastic. Despite pouring rain on two days and blistering hot sun the other three, all teams moved quickly and often finished early. We had a few new volunteers this round, and were missing a few from the deployment, but people rarely had problems finding cups other people had placed (or hidden), which we had anticipated being the hardest part of the process.

Physically, a majority of the traps were in great working condition. Of the 5300 traps set out and revisited, we surveyed over 1300 in detail, noting things such as damage, mold, water level, and presence of eggs on the strips. Based on the survey data:
-98.9% of traps were still present. The few that were gone had been removed for a variety of reasons, including construction/landscaping, and overzealous gardeners.
-97.3% were undamaged. The majority of structural damage appeared to be due to weed whackers, which as you can imagine do not discriminate well between vegetation and plastic. That 2.7% damage rate includes the few traps that had problems with the strips becoming detached and falling to the bottom of the cups, rendering those traps nonfunctional.
-Only 8.7% of the strips surveyed had any sort of mold on the surface. Many had organic debris or other obstructions on the velour surface, but we did not see nearly the same level of mold growth as had been a problem in some previous tropical studies.
-95.2% of cups still held water, without any sort of topping-off in the last month other than what rainfall could reach them. The dry ones were mainly well-hidden under dense vegetation where they got no rain. On average the cups were still up to 69% of their original fill level, which is more than enough to be attractive to gravid Ae. aegypti females.
-Cage bioassays of strips recovered from the field still produced as much as 98% mortality with lab strains of Ae aegypti, even after the sun and water weathering, and despite concerns that the high pH of Key West municipal water may have degraded the bifenthrin quickly.

There is an indication that a small percentage of the traps (2.2%) contained viable mosquito stages. A focused effort has been launched to determine if some of the Key West mosquitoes are genetically resistant to the pesticide used, or if some other factor allowed these mosquitoes to survive. This may require a program modification; we are discussing the possible options with all program collaborators.

Regardless of this unexpected finding, keep in mind that overall the results were overwhelmingly positive. Physically, the traps are in great shape. A vast majority of homeowners had no problem with the traps. We have learned how many people and how much time it takes to deploy a large number of TNKs over a large area. Many of the first-round logistical difficulties have been identified and can be refined. Even the presence of immatures is somewhat of a good sign – it means that mosquitoes are visiting the traps, which was somewhat of a black box going into the deployment. As long as we can get the mosquitoes to visit the trap, which is the difficult and unpredictable part, selecting the proper insecticide becomes a relatively straightforward question of chemistry and going through the appropriate regulatory steps.

Also, we are still processing the rest of the population data, but preliminary analysis shows some promising numbers. Between exhaustive sweeps (larval surveys), more focused (pupal) surveys, and adult trapping, there are a lot of numbers to crunch. Stay tuned, there’s more to come!

Hello again from Woodinville!

It has been a productive last few weeks. Among other exciting news, we have tweaked our production process, resulting in a substantial increase in mortality in cage trials. The ovistrips we produced for the first deployment were just above our threshold for acceptable mosquito mortality; the new ones are showing 95%+ mortality in just 24 hours!

We have also been in contact with a number of people who are interested in starting their own trials with the Trap-N-Kill system. I guess word has gotten out about the Key West study, because there’s a lot of interest from several angles! We are still looking into timing and feasibility of other tests, both this year and next year… but we will be sure to update you when we find out more!

As for Key West, everything is proceeding right on schedule. In just three more days, we will be on the ground and starting our first round of ovistrip replacements. Most of the team from last month, including three of us from SpringStar, will be back. Our plan is to revisit all traps that were placed in the first round, replacing strips, refilling water, and making any other necessary adjustments to ensure the TNKs are still in good working order. Additionally, we will be collecting data from random samples of the TNKs, as well as collecting population data from the general treatment and control blocks, to see what kind of an impact we are having in the Aedes aegypti population, and to see how well the traps and strips are holding up in the hot, humid Florida weather.

In the past few weeks since our visit, the FKMCD staff have been hard at work, collecting population data as well as maintaining their high level of prevention and treatment for all mosquito species. We look forward to their results – we’re definitely excited to see how these traps are affecting the mosquitoes. A lot hinges on the data, but we’re confident that we shall see positive results, and soon. Keep checking back – we’ll get some preliminary results posted one of these days!

Well, that’s all I have for now. See you in Florida!

For those of you who prefer numbers to pictures, here is a quick summary of the Trap-N-Kill deployment:
-3 days of deployment, 5300 traps placed in approximately 200 acres
-24 teams of 2 people per team doing the deployment
-50 acres and 1600 traps the first day (including the 23 acre Old Town Cemetery)
-90 acres and 2100 traps the second day
-55 acres and 1600 traps the third day
-2 radio spots discussing the dengue problem and the Trap-N-Kill
-95-99% resident acceptance of the traps

The original plan was to deploy approximately 3 times this number of traps, but after we lost some volunteers to the last-minutes rescheduling, we scaled back the size of each treatment block. However, “scaling back” does not mean we went small!

Previous field trials or deployments in places such as Brazil, Thailand, and Australia have used between 400 and 600 traps, in combination with other control methods (as we did here) – we placed 10 times that number! Those previous studies have also focused on placing traps within a 100-200m radius of confirmed dengue cases, and still saw significant results both in terms of vector abundance and disease transmission.

So where do we go from here?

Read the rest of this entry »

Here are a few pictures from the three days of deployment, although less than we had planned – we were all too busy setting traps!

Our deployment crew consisted of: the  Florida Keys Mosquito Control District personnel; 5 of us from SpringStar; Lt. Col. Doug Burkett, who is part of the DWFP program and in charge of funding this project; Graham White, part of the DWFP and USDA-ARS, FL; Brian Zeichner, one of two co-inventors of the lethal ovitrap, and his lovely wife; and several volunteers from the Key West Naval Air Station.

Photos in extended…

Read the rest of this entry »

Hello from Key West! We landed around noon on Tuesday, met with our cooperators from the Florida Keys Mosquito Control District (FKMCD) to finalize protocol and make sure all supplies were prepared and ready to go. Due to the rescheduling, we were down in numbers, so the decision was made to slightly reduce the size of the treatment blocks. This will allow us to collect statistically sound data while still treating the critical areas of Old Town.

Today, we started near the Old Town Cemetary, which is somewhat of a hot-spot for the dengue vector, Aedes aegypti and near a majority of this year’s confirmed dengue cases. Teams of 2 were assigned 2-4 blocks to cover, with a plan to place 4-10 Trap-N-Kill cups per house in addition to standard FKMCD treatment.  Depending on conditions at the house, this treatment could consist of emptying out standing water sources, treating water that couldn’t be emptied with Altosid or VectoBac, or hand fogging the yard with MosquitoMist.  At least 4 Trap-N-Kills were placed per house, with up to 10 based on number of alternate breeding sites (standing water) and local conditions.  The number of houses covered today will set the benchmark for the amount of area we will cover the next two days.  All residents were  given an informational flier on the Trap-N-Kill, with contact information for both SpringStar and FKMCD should they have additional questions.

Despite somewhat of a learning curve, all teams were able to complete their assigned blocks, which means we are on target to complete the planned (resized) deployment by Friday! We were met with a generally positive reception by the residents – FKMCD has done a terrific job of working with residents and building a good rapport with them, which is critical to the smooth and effective treatment of an area like Key West, especially in light of the continuing dengue cases.  Most of the residents I talked to were friendly and eager to assist our efforts in any way they could. All in all, this was an encouraging start to what we expect will be a productive trial.

Pictures to come!

The mosquitoes said they did not like the production batch of TnK Traps as much as they did before!  Our cooperators and science team want the best possible outcome, so the program has been held one week.  Stay tuned for more.

The link at the right for the Complete Brochure contains the entire submission and Florida approval for our Key West Trial.  Included is the Final Product Label, Test Protocol, MSDS, and Toxicology Review.  This brochure is appropriate for professional mosquito abatement personnel working on the project, or interested in the project.

The tabs on the right side of the blog have links to our Trap-N-Kill(r) Product Information brochures.  Every home that receives traps will have a brochure left at the door, or if you are home, you will be handed a brochure by the Florida Keys Mosquito Control District (FKMCD) representative that visits.  If you are not part of the Trap-N-Kill treatment block, feel free to download the brochure anyway.  We will also have printed brochures in English and Spanish available at our information booth and at the FKMCD offices.

Florida State granted an  emergency use permit to deploy the Trap-N-Kill mosquito traps in the Florida Keys.   People wanting to know more can check out our brief pamphlet (In English and Spanish).  We’ll have news up shortly about where local residents can meet with us to discuss their questions or concerns.  We intend to have an informational booth set up from July 7th to the 9th for people to stop by and get more information.  Traps will be placed in 3 areas of Old Town for a 3 month test starting July 7.

For now though, welcome!  We’re looking forward to reducing the mosquito population!