Mixing HAL Gel Bait for
Control of Little Fire Ants
Little Fire Ant (LFA) are very difficult to control. They have many small colonies, each with many queens, and will have nests on the ground as well as in trees and other vegetation. All these small colonies are inter-connected and if some die out, they are re-populated by neighboring colonies.
One problem facing the homeowner is that virtually all commercial baits consist of small granules. These are easy to spread on the ground, but can not be applied to vegetation. Ants in the trees will not necessarily come to the ground to forage on the granules. If only the colonies on the ground are treated, neighboring ants living in trees will quickly spread back to the ground.
Hawai`i Ant Lab (HAL) has developed a basic gel bait recipe that can be applied to vegetation where it will stick to the leaves and branches.
Why Use Gel Baits?
Ants consume gel baits far more easily than granular baits
Contrary to popular belief, worker ants do not eat solids – they only consume liquids. Most granular baits are made from corn grits and vegetable oil, and when a worker ant finds a bait granule, she often sucks the oil out of the granule and leaves the rest behind.
Gel baits stick to the trunk and branches of trees
Little Fire Ants often nest in the foliage and branches of trees. These may not be well controlled with standard bait applications, because the tree-dwelling ants do not always forage on the ground. Most baits are granular and so can not be applied to trees. If you have trees over 6 ft. tall, Hawaii Ant Lab’s gel baits are your only effective bait option.
Gel baits are more tolerant to moisture than granular baits
Granular baits are inactivated by rainfall. Once the granules become soggy, they are no longer attractive to ants. Windward locations in Hawai`i often experience regular and frequent rain. In some locations it is difficult to predict if it will rain on any given day.
Options For Active Ingredients
There are a couple pesticides that, added to the HAL gel bait, are effective at controlling Little Fire Ants. Only mix one pesticide choice in a batch of gel bait: Tango™ OR Provaunt®.
Tango™ is a concentrate product that contains (S)-methoprene, an insect growth regulator (or IGR). The label provides instructions for mixing the concentrate with a bait matrix. The manufacturer has also issued a 2(ee) recommendation that provides specific instructions for treating LFA.
How does it work?
The IGR group of chemicals work by preventing affected insect larvae from completing the pupation process but has no effect on adult worker ants. It also prevents or slows down egg production by the queen. Ant colonies baited with an IGR will start to see a reduction in population after 3-4 months as worker ants die from natural causes and are not being replaced by new workers.
The active ingredient (s)-methoprene is one of the safest insecticides available today. For this reason, it is often used for insect control in food crops and even drinking water. Tango™ is registered for use on and under food plants. It is extremely effective as an ant bait when added to the HAL gel bait.
Tango™ takes longer to control insect pests because only egg production and larvae are affected, while the adults can live on. In today’s world we often expect quick results and for some people 3 months is a long time to wait for results.
The slow mode of action typical of (s)-methoprene baits means you will continue to see ants for 3-4 months, or even longer. Be patient and repeat treatments every 4-6 weeks for at least a year. The repeat treatments will ensure that all colonies are properly treated. If only some colonies are controlled, the surviving ones will spread very quickly and all your efforts will have been in vain.
After a few months of treating with IGR’s you may start to see fewer workers, but an awful lot of winged queens, which are larger than the workers. DON’T PANIC! This is a normal side effect of IGRs. It’s a sign the bait is working!
Provaunt® is a water soluble granule that contains the active ingredient indoxacarb, a toxicant. The manufacturer of Provaunt® has applied for and been issued with a “Special Local Need” permit (or SLN) which allows users in Hawai`i to add Provaunt® to the HAL gel bait for control of LFA.
How does it work?
The active ingredient, indoxacarb, is in a new class of chemicals known as oxadiazines. When LFA ingest indoxacarb, it works as a sodium channel blocker resulting in paralysis and eventual death within 2-3 days.
Provaunt® is fast acting and usually dramatic results will be noticed in as little as 2-3 days after treatment.
Provaunt® is not registered for use on food plants or within the drip line of food-bearing trees nor for ground treatment.
LFA can completely recover from a single bait treatment in 8-10 weeks. The reason they can recover so quickly is that there are many queens in the colony, so even if some are killed by a treatment, the remaining queens simply increase their rate of egg production until the population gets back to normal levels.
However, when we apply a bait product, the surviving ants learn that the baits are toxic to them and will avoid feeding on that bait. So, the next treatment needs to be sooner than the time it takes for the colony to recover, but not so soon that the ants will avoid the baits. We recommend that people treat every 4-6 weeks for at least a year.
Gel Bait Recipe
This is NOT a job to be done in your kitchen, or using bowls and measuring cups that will later be used to prepare food.
Buy all these items specifically for this purpose, mark them “Not for Food Use” or “Pesticide Use Only” and keep them in the garage or wherever you normally keep your yard care products or other chemicals.
Read the pesticide label very carefully before starting and make sure you follow all directions and precautions listed.
Put on your proper personal protective equipment (PPE) including chemical resistant gloves, eye protection, long sleeved shirt, long pants, and closed toed shoes plus socks.
Combine the water and pesticide (Tango™ or Provaunt®) in a bucket.
Start mixing at a slow speed with your drill and paint mixer attachment (kitchen whisk modified so it can be fitted into the drill chuck also works well) and very slowly add the Xanthan gum. Continue to mix at the highest speed safely possible until everything is evenly combined. It should look like a thick, sticky goop. It can be difficult to mix the Xanthan gum so be patient and dust it in very slowly. If not thoroughly mixed, little lumps can clog the nozzle of spray equipment.
Add the peanut butter and mix thoroughly. Then add the oil. At this point, the oil will sit on top of the water/xanthan mixture. Mix at high speed until evenly combined. The bait should now have the same consistency as thin pudding or gravy.
Pour gel bait into the ZEP spray bottle using a funnel. If treating a larger area, a Jacto backpack sprayer is well-suited to hold larger quantities of gel bait. Broadcast gel bait around your property at a rate of 1-2 gallons per acre. Apply on a day with 4 hours of dry weather after treatment. Repeat treatment every 4-6 weeks. After completing a year of treatment, check your property for LFA. If still present, continue treatment.
Video: How to mix HAL gel bait
Step-by-step video on how to mix a gel bait using Tango.
Directions for Use
Video: How to
apply HAL gel bait
This gel bait basics video includes which bait products to use in a gel bait matrix and best application methods.
The finished bait will have a pudding-like consistency and not every sprayer is suitable for use with this product. However, there are several equipment options available for applying the gel bait and your choice will depend on how much area you need to cover and your budget.
Good quality water spray bottles are available at most garden exchanges and hardware stores. The very cheap types do not work very well, so choose a high quality one like a 32 oz. Zep brand or similar. These better-quality spray bottles can shoot a stream of bait more than 15 feet, making it very easy to target ant colonies nesting in trees. Remove the filter at the bottom of the intake tube before using. The filter is too fine to allow the gel into the spray pump. Also, have a wide-mouthed funnel available to fill the spray bottle.
Pump-up sprayers use compressed air to drive the bait out of the nozzle. These are usually pressurized by the user pumping air into the spray bottle (like pumping a tire) before use. We have tested a few of these and most are not very effective. The Redmax HM20 and possibly other good quality sprayers work very well. We replace the wand and nozzle with a “D2” spray nozzle for best results. These have an effective spray distance of over 20 feet but require a strong arm to pump.
Lever-type sprayers use an external lever to operate a pump inside the sprayer (but does not pressurize the sprayer itself). The type of pump influences how well these sprayers work with a thick liquid like the HAL gel bait. One pump that seems to be very effective is the “Jacto” sprayer. This has a piston pump which is more effective at spraying thick liquids. The Jacto sprayers have a spray distance of up to 30 feet. As with the Redmax, we remove the wand and replace it with a “D2” spray nozzle.