There’s nothing worse than discovering your bees have been poisoned. The once busy entrance, now silent with only a few twitching bees in carpet of dead below. The suddenness of a colony lost to pesticide poisoning is shocking. What follows is often heartbreaking, humbling and infuriating. So, how do you know if your colony has been poisoned? What do you do if it happens and how can you prevent it if it hasn’t yet? Read on to find out everything you need to know about how to protect your bees and other pollinators from this terrible ordeal.
Recognizing Pesticide Poisoning
Since honey bees will fly up to three miles to forage, urban beekeepers are particularly at risk form pesticides. Unlike agricultural settings, most urban and suburban homeowners are free to use pesticides without restrictions, licensing or instruction. If one of your neighbors uses a pesticide improperly, it can devastate nearby beehives. The improper use of a pesticide can include: using too much, applying it to plants when they are in bloom, or applying it at the wrong time of day. It’s important to understand that the majority of these incidents happen as a result of ignorance, not malice. Many simply fail to read instructions before using the product they buy and do so without an understanding of the consequences their actions have.
When your colony experiences acute pesticide poisoning, you will see:
- A sudden drop in foragers.
- A large mat of dead bees in front of your hive.
- Spinning, skipping and disoriented bees on the ground around your hive.
- Bees dropping from the frames when you lift them out.
- Dead bees on the bottom board.
How to Help a Poisoned Hive Recover
Unfortunately, most poisoned hives never recover, but in most cases it is a simple numbers game. The bigger your colony is, the better it’s chance of survival. Once pesticides knock out the field bees, the population will be drastically reduced. A hive with a low population is now at risk for a number of other problems because it will not have the necessary workforce needed to complete daily tasks.
One big one is cleanliness. A poisoned hive an easily become overwhelmed with the housework or cleaning out dead bees and any poisoned larvae. You can’t do much to help dead larvae in the cells. If you notice a particular comb that does not appear to be occupied anymore and it contains dead larvae you should consider pulling it out of the hive. If you find dead bees on the bottom board, be sure to clear them out of the hive to prevent any secondary bacterial infections from taking hold. It is a good idea to check your bottom board every few days after a poisoning if the bees seem overwhelmed with dead bodies.
Another big problem is food stores. Without foragers, your bees will be forced to live on what they have. If their stores are low, they can end up dying of starvation! Make sure your bees have enough pollen and honey stores and if they do not you should feed them until they can build up their population again.
It is very common for a colony that has been poisoned to end up queenless and it does not always happen right away. You should take special care not to overlook the symptoms of a colony that has lost its queen. If you notice your bees are making new queens, you should let them or replace her yourself. It is likely that your queen has been damaged or killed by the pesticide exposure. In most cases, a colony will have a better chance of survival if you requeen them. I usually wait several weeks after the poisoning before doing this to be sure they have a shot at survival.
As a general rule of thumb, I recommend you reduce the entrance whenever a colony is weakened to protect them from predators. Be sure to do this when your colony is recovering from a poisoning as well as they will be extremely vulnerable.
Another important thing to know is that a colony whose population drops suddenly can also fall victim to mites, moths and beetles. Keep a close eye out for these villains in the weeks following the poisoning and take appropriate action against them if you see any signs. It’s a good idea to head off moths and beetles by removing any abandoned comb. A weakened colony may not have the resources to defend all of the combs they once occupied. When mites take hold it can be a tough choice for how best to help the bees. Doing nothing will surely mean collapse, but most mite treatments will be too harsh for a colony weakened by pesticides. Each case deserves its own unique solution. My preference is to requeen, shake powdered sugar and to add capped brood and nurse bees from a stronger hive to increase the population.
Lastly, you will need to be patient. It will take months for beehive to recover from poisoning if they don’t die outright. Even though there are things you can do to help them, time is the biggest healer. Make sure you are not opening your hive too often, you will only hinder their recover. In this situation, having a viewing window on your hive can be extremely helpful. It will allow you to check the bees without disturbing them.
A Case Study
The above are photos of a student’s rooftop apiary which was poisoned in July of 2016 and exhibited all of the above symptoms and obstacles to recovery. Her two new colonies were thriving and just beginning to fill their second brood box with honeycomb when disaster struck. Nearly all of the foragers were poisoned. Many of them never made it back to the hives, but several hundred did and unfortunately, they passed on the poison to the house bees. When this happens, you will find dead bees inside the hive and young bees will drop off the frames when you lift them out. At this stage of poisoning, a colonies’ chance of survival is minimal. In this particular case we have managed to keep both colonies alive so far (it has been five months), but it took a lot of effort and the bees still have not fully recovered.
Initially, both colonies had little to no foraging activity and struggled with the house chores because of a reduced population. Their population was less than half of what it was. We moved quickly to reduce their hive cavity, pulling out combs they had abandoned. We began feeding them and we waited. After several weeks, the mite population spiked dangerously. We dusted the bees with powdered sugar to increase mite drop and decided to requeen one of the hives. Normally, I would have requeened both hives, but we decided to experiment. Hive A accepted the new queen and began to improve, but still lacked the necessary population to make their recovery. We ended up heavily subsiding their population by adding several frames of capped brood and nurse bees from one of my own large strong colonies. The same was done for Hive B which was not requeened. Hive A is now improving slowly, but surely, while Hive B continues to struggle. Hive B reccently requeened themselves successfully and we hope the new queen will turn them around, but we continue to monitor them closely.
Below is an example of a flyer I distribute to neighbors after a poisoning incident in hopes of preventing it from happening again. One of the worst parts of losing a colony to pesticide poisoning is the knowledge that it can easily happen again. Your best chance is to take action and educate your neighbors about pesticide use. If you can speak to your neighbors in person, it will be more affective, but it is good to leave them with something they can refer back to. It’s an even better idea to hand out a modified version of this flyer before a poisoning incident occurs.
Preventing Pesticide Poisoning
We cannot control where our bees go to forage, but what we can do is educate our communities about protecting our pollinators with responsible pest management practices. Some strategies for reaching your neighbors include: door-to-door canvassing with educational pamphlets, posting on online community forums, contacting local leaders or news organizations, and volunteering to speak to garden groups. Here is some useful information to share when employing these outreach strategies.
Pesticides are not always necessary. When a plant is under stress, it’s susceptible to pests and other problems. When you use a pesticide or a fungicide you are really only treating a symptom and not the problem. The problem often lies in the soil. Poor soil health leads to weak plants which leads to pest problems. So, before dousing your plant in pesticides, you might want to investigate whether the soil needs to be amended.
Pick your poison carefully. Some pesticides are more harmful to bees than others and even the ones that are less harmful can still do damaged when applied incorrectly. If you feel that you need to use a pesticide, research which ones are most appropriate and least harmful to the bees. Most people do not realize that organic pesticides will still harm bees.
Application matters. Always read the directions on your pesticide product, but in general to protect pollinators, you should not treat plants that are in bloom. It is also important to apply the pesticide in the evening so that it is less likely the bees will encounter it and you should not apply the pesticide in windy or wet conditions because this can lead to drift.