Dealing with Yellow Jackets, Wasps, and Other Honey Bee Predators

Yellow Jackets, wasps, boldface hornets, and other flying predators are good to keep some plant parasites on check. They eat aphids and larvae of insects that could damage plants.

But if they are present in excess, they could cause some honey bee colony losses. A nest of yellow jackets could overrun a strong colony and kill it within a couple of days.

Beekeepers should try to maintain a healthy level of flying predators around their bee yards. This will keep their garden plants healthy with the help of flying predators without allowing them to cause damage to honey bee colonies.

At our BeeManiacs yard we take this approach:

Set traps early in the spring, to catch queens and prevent nests from being formed (you are preventing one nest per early queen you catch).

Control flying predator populations by resetting the traps through the season. We recommend the WHY trap, which is intended to trap Wasps, Hornets, and Yellow Jackets.

If at any point you notice the flying predators keep trying to enter your hives, increase/refresh traps and restrict hive entrance areas by using entrance reducers or metal mesh/hardware cloth.

By late summer or fall, the yellow jacket predatory pressure on your hives could increase because of the reduction of food available to them.

When yellow jacket pressure becomes too high you will notice an increase of yellow jackets flying around hive entrances and trying to enter hives. When a hive is opened, yellow jackets will immediately fly straight into it and attack honey bees. If you kill a yellow jacket with your hive tool (we do it all the time), you may see two or three more yellow jackets coming to eat the dead one.

In cases of high predatory pressure, the traps may become ineffective because they’re not interested in your bait (they’d rather eat honey bees than the bait you loaded in the traps) or just because there are so many yellow jackets that you cannot trap all the ones you should remove to keep your hives safe.

In cases like this, we bring a bait/poison combination that kills all the nests in the area.

Some universities have performed some research and experimentation to find the best combination of bait and poison load that would allow extermination of the nest itself.

The smell and taste of the bait need to be more attractive to yellow jackets than the smell of honey bee brood.

The poison strength and concentration need to be measured carefully. Too little poison and the nest keeps growing. Too much poison and the foragers die before bringing the toxic food back to the nest. An even higher amount of poison would act as a repellent and the yellow jackets would skip your bait.

These flying predators are in the Hymenoptera Order, which is the same than ants. Many poisons/baits that are made to kill ant nests will also be effective to kill yellow jacket nests.

After experimentation on different combinations this is the best bait/poison combination we can recommend:

Bait

  • Purina Friskies® Ocean Whitefish Dinner
  • Purina Friskies® Supreme Supper
  • Purina Friskies® Mixed Grill
  • Swanson’s® brand canned minced white chicken

For the bait, you can start with these options to begin with, but you could switch bait to whatever food attracts the yellow jackets in your area. The best bait would be the one that gets the job done at minimal cost.

Poison

  • Fipronil in concentrations between 0.0025% to 0.025% was the most effective

Poison concentration was calculated including the bait food. Fipronil can be found in different products to kill ants or even control parasites in dogs. You will have to look at the concentration of the active ingredient on the product you purchase and calculate how much product to add to the bait, to have the right final concentration.

How to calculate the bait/poison mix

In the following picture, you can see the components we selected to prepare the bait.

The can of cat food has a 1.65” radius (r) and 1.25” height (h), so the volume is: V=πr2h which is about 10.7 cubic inches or about 6 fl oz.

For a concentration between 0.0025% to 0.025% of Fipronil we have to add from 0.00015 to 0.0015 fl oz of pure Fipronil.

The product we are using comes as a solution at a concentration of 9.1% Fipronil active ingredient, so we should add from 0.0016 to 0.016 fl oz of Fipronil solution. For calculating how much Fipronil solution you have to add to your cat food can, you can use this equation:

0.015 / concentration of your Fipronil product = minimum amount to add
0.15 / concentration of your Fipronil product = maximum amount to add

One drop of liquid is about 0.0017 fl oz, so a range of 1 to 10 drops of Fipronil solution can be used. We use an average of 5 drops then mix it well into the whole can of cat food.

Delivery system
You will need to set the bait with poison inside some kind of cage or protective equipment that can allow the yellow jackets to access the bait without allowing any other animals to reach it.

Further reading

Yellow Jacket Control in California: https://www.pestboard.ca.gov/howdoi/research/2009_yellowjacket.pdf

Paper by Master Beekeeper Sandy Fanara: https://www.wpbeekeepers.org/presentationnotes/YellowJackets.pdf

Fat Body

Honey bees have what is called a “fat body” which is a section of tissue that holds fat cells, as well as glycogen, protein, and high concentrations of mitochondria and enzymes. The fat body is the equivalent in insect terms of a mix of a liver and fat storage.

During larval state, the fat body covers most of the larvae. The fat body will quickly and efficiently store nutrients during the larval stage to be used during the pupae stage (while the bee is not fed) and the adult bee will emerge with a fat body only in her abdomen.

The fat body is extremely important for winter bees (aka fat bees). Winter bees have a bigger fat body that would allow them to store more energy and nutrients that will last for months. Summer bees have a smaller fat body and in some cases almost non-existent.

Why is fat body important?

Recent studies on the parasitic varroa mite found out that the varroa mite is not actually sucking hemolymph (bee blood) our of the larvae and the honey bee, but it’s actually eating fat body cells, which are higher in nutrients. Different experiments determined that the mite could not extract enough energy by sucking hemolymph (which has a lower concentration of nutrients) and that it would not be as detrimental to bee health to lose some hemolymph.

By taking fat body cells, the varroa mite can take a higher nutritional material that would allow for fast growth and reproduction. Taking fat body is more detrimental to the honey bee colony’s health, especially over the end of the season when the mites feed on what were supposed to become winter bees. The winter bees that fed varroa mites have a smaller fat body and will not be able to survive for as long as the colony intended when raised those bees.

This explains some of the abrupt colony collapses that beekeepers find by the end of fall when stronger hives (big in numbers and resources) end up dying before even getting to winter.

 

Foraging for water and its uses

Honeybees, like any other animal, need water to survive.

While the flowers produce nectar, the bees can obtain carbohydrates (sugar) and water out of the nectar itself. Nectar is a watery sweet liquid with sugar concentrations around 20% (water concentration could be from 35 to 85%).

When nectar is not available or the amount of water from the nectar is not enough, honey bees will have to forage for water to cover their needs.

Water foragers have a specific skill set since foraging for water is a little harder than foraging for nectar.

Bees will have to store the water in their crop (or honey sac or honey stomach). The crop is the first reservoir where liquids are stored and can be kept separated from the digestive system (by closing the proventricular valve).

To forage for water, the honey bee will have to take only enough honey/nectar from the hive to consume during transit and arriving at the water source with an almost empty crop. As she takes water in, any remaining sugar in the crop will be diluted. She now has to make it back to the hive, by consuming carbohydrates that are stored in her body, without being able to consume any calories from her water-filled crop.

Once she arrives at the hive, she needs to get in contact with other workers to pass the water to them, so she can empty her crop and take some honey/nectar to replenish her energy.

Honey bees need water to:

  • cool down the brood area on hot days (evaporative cooling)
  • increasing moisture in the brood area
  • diluting stored honey for consumption
  • making of royal jelly (about 67% water)

Honey bee brood is very sensitive to relative humidity levels. Optimum brood-rearing requires 90 to 95% relative humidity (RH). If RH is below 50%, the eggs cannot eclode (emerge) and die after three days. With RH levels below 80% or above 95%, there is a significant drop in eclosion success (many eggs fail to dissolve their outer layer and turn into larvae).

As beekeepers, it’s very important to provide water sources for our own bees. Not only because it’s hard on the bees foraging for water, but also to prevent our backyard bees to bother neighbors.

And while talking about preventing our bees to visit neighbors, it’s always a good idea to provide multiple sources of water:

  • plain water – just regular tap or well water
  • chlorinated water – if any neighbor has a chlorinated swimming pool, you should add a source of chlorinated water to prevent your bees visiting his pool
  • salted water – to provide for minerals. Otherwise, they may visit neighbors with horses or visit watering bouls from dogs (to get the salt out of their saliva droplets)

You can see below a picture of our yard watering station. We placed it right next to the garden faucet.

The in-ground plastic insert contains regular water. It also gets refilled when it rains. We added some holes on the side of the plastic tank, to make sure that the water never covers the rocks. The bees need landing spots where they can safely walk to the water line (honey bees drown easily if they fall into the water).

The metallic container is a chicken waterer where we added some mineral salts (table salr works, but we used minera salts sold in farm supply stores). The rocks were added to make sure the bees land safely. This salty water location provides the bees with minerals so they won’t bother our neighbor horses and dogs:

WA State Apiary Registration

If you own or manage honey bee colonies that at any time of the year are going to be settled in a WA State location, you will have to register with the WA State Department of Agriculture (WSDA).

The deadline for registering without having to pay late fees is April 1st of each year.

The WSDA collects all fees and the proceeds are used to fund honey bee research. The payment is not a tax. The WSDA only administers the collection and distribution of the funds.

You can find more information and the link to download the registration form for the current year in this link: https://agr.wa.gov/plantsinsects/apiary/default.aspx