Ick, a 6 month systemic!

Yes, systemics (and Imidacloprid is the most popular and most studied) have been found in pollen and nectar. This poses a risk to every single member of the hive, including the queen. The larvae,in particular, are fed a condensed version of nectar. One would think that they would be especially prone to harm.

However, those worker bees assigned to the job of foraging for nectar and pollen are the oldest members of a functioning hive. Younger workers have essential jobs inside the hive. So, it is pretty normal to find dead foragers at any given time.

The only way to get those who professionally grow young trees to stop using systemics such as Imidacloprid is to stop buying their plants. Ask at the nursery (or your Big Box Store) if they ever sell any trees that have not been treated. If not, why not? Walk out empty handed.

As an aside, many companies who have always provided hives of honey bees to commercial orchards over the generations have now ceased dealing with those growers who will not agree to stop spraying their trees. The bee suppliers were picking up empty hives upon the end of the contract period.

No proof that the pesticides were the culprit, but it seems a reasonable deduction that chemicals were at least part of the problem.

I'm sorry to hear that I could be adding to the problems bees are having. However, my trees are already in the ground. I could pinch off blossoms, but I understand the tree may respond by producing new ones.

I won't be applying systemic or toxic pesticides. However, I understand the need of the citrus industry to control the citrus greening disease by the use of these poisons.
Marcia

I have to use neem here in South Florida to keep the Citrus Leaf Miners from completely destroying the leaves on my citrus trees. Unfortunately neem oil kills bees also.

Ken

Neem, when used properly, will do very little damage to bees. Try to avoid getting Neem directly on open flowers, and don't spray when bees are flying all over the place.

Marcia, just so you understand clearly what ISD means: It stands for Imidacloprid Soil Drench. Imidicloprid is a systemic insecticide used very commonly by professionals and homeowners alike. Unfortunately.

Thanks for explaining what ISD is, Rhizo. I won't be using it. I don't know how long it will persist in the soil around the trees or in the leaves and blossoms of the trees. Maybe I will nip off the rest of the blossoms. The trees are small--5 or 7 gallon size--and enough fruit has started to form on them. Even if all the fruit falls off, I won't be too disappointed since I really didn't expect to get fruit from them this year anyway. I'm really unhappy seeing those dead bees around the trees.
Marcia

Don't blame all the dead bees onto whatever was used on the plant. Adult bees which forage for pollen & nectar have a very brief life.

Jean, what I haven't mentioned is that the bees I see dying have some kind of spasms/shaking before dying. They just lay on the ground and shake. I think that's one of the symptoms of Imidacloprid poisoning, as it affects nerve function. If it were just one or two bees, I might think it was just old workers. But a dozen in the last couple days, and of different species, too. I hope I'm wrong but I don't know how else to explain it.
Marcia

There's really no way of telling what might be killing the bees. Perhaps someone near you has been using a pesticide, or maybe it just normal, as both Jean and I have suggested.

Bees can travel quite far on their foraging trips, so there's no telling what kinds of chemicals they've been exposed to.

You're right, Rhizo. I just felt better by nipping off the rest of the blossoms. No blossoms, no reason for the bees to visit the tree, and no more corpses for me to look at. Maybe my trees aren't to blame for the deaths, but I'm happy with my decision. It probably won't make a big difference one way or another.

Thanks for commenting.
Marcia

You're a good bee care-person, Marcia. We could sure use more like you!

Marcia:
Our bees and most of my other benificials are killed by the Mosquito Control District, an arm of our county govt.
This has intensified since West Nile virus.

That's interesting, Tantanman. I know they spray the ditches and canals here for mosquitoes but I don't know what poison they use and/or that it might affect the bees. Another sad fact.
Marcia

The primary chemicals used for mosquito abatement programs are one of the pyrethrins. They may also use malathion. Both are deadly to bees and other insects and animals. Even in the very low volumes that are dispersed with specialized equipment, other animals species (which includes insects) can be very detrimentally affected.

Sometimes, they will use a Bt (Bacillus thuringiensis) strain of bacteria that controls mosquito larvae, and only mosquito larvea. It may control some species of gnats, too, if their larvae are aquatic. If they are just spraying the waterways, that's probably what they are using. Bt is relatively safe to use; not known to be harmful to mammals, other insects, aquatic animals, etc. Some people are allergic to Bt, so it's worth keeping that in mind if problems develop after an application.

Overhead (airplane) or street (truck) abatement will focus on the adults, though it does a very poor job at killing enough mosquitoes to justify the environmental damage or health problems for those who may be sensitive to chemicals.

When my trees were very small I used a netting purchased from a fabric store. Black netting is the least noticeable. If you enclose the canopy with the netting, few insects will get through. In fact, as long as I used the netting, not even aphids or scale got through. I think that the appearance may even fool some insects and they'll stay away.