Pollination in Pennsylvania Apple and Cherry Orchards

- My name's Dave Biddinger, I'm the research tree fruit entomologist based down by Gettysburg.

And I'm gonna talk today about some good news.

I probably started work with the bees about 2008.

And back then, you go to the E.S.A. meetings, entomology meetings, and be two-hundred talks on honey bees, a couple on bumble bees, and maybe one or two on solitary bees.

That's completely switched, to where everybody's starting to realize those wild bees were out there doing something for a long time, and nobody took notice of them.

This was actually a shed, these are my Osmia nests in there, back in a wooded site.

We didn't have much of a budget back then.

It's gotten a lot better. (crowd laughs)

For those of us that have been preaching to the choir for a long time about wild bees, we're finally being heard, and we're finally relevant.

So, a reason I like these guys is because of the diversity.

(crowd laughs)

That shows you the big bee and the littlest bee around this area, and I'll pose the question to kids that come in, or extension people, What do you think has more diversity: bees or fish?

And there's only 19,000 species of fish, saltwater and freshwater, in the world.

But 22,000 kinds of bees, which sounds like a lot, but I used to work on parasitic hymenoptera, were hundreds of thousands per family, so at least these are named, and we can figure out what they do for the most part.

Like I said, most of my career has actually been working on pesticides to control the pests, but a large part of my career has been looking at reduced risk pesticides, to develop these selective insecticides that were safer to people.

But basically what we've been trying to do is get away from the broad-spectrum insecticides that are like a tank that you killed everybody for miles around.

Well, Food Quality Protection Act came in and says, "Those things are too toxic to people.

"Let's start doing reduced-risk pesticides," of which Neonics were part of it.

And they're a lot safer to people.

And then, the ultimate is the pheromone disruption where you don't actually kill the thing, you just get him really frustrated 'cause he can't find the female.

(crowd chuckles)

And I, being a taxonomist, I like to look at all the different predators and parasitoids that are out there that help control a lot of our secondary pests.

We have no tolerance for things like codling moth in your apple, you don't want half of a codling moth in your apple, 'cause you know where the other half went.

So, there are certain pests we call "secondary pests," like aphids, and scale insects, and things like that that we can control if we don't take away their biological control, and even more important are these parasitoids, which help regulate populations in an unsprayed orchard.

You don't see a whole lot of these in the past in orchards because most pesticides wiped them out.

And a large part of my career has been documenting which of these guys are starting to come back, and it wasn't a big step to make the step from conserving beneficial insects to conserving bees.

To me, it was just another way of conserving a good bug to give those ecosystem services.

And for all my not liking honey bees, they are very important in tree fruit.

The estimated value for tree fruits is about $4 billion, just for honey bees.

And there's some advantages of honey bees.

You put them in a box, basically you stop spraying, apple blooms only about seven to ten days long, you put the honey bees in the hive, you stop spraying, you come back, take the honey bees out, move them away, and then you can start spraying again.

When you rely on wild bees, they're out there constantly, so you have to worry about those early-season sprays, getting in the nectar and pollen, whether it's insecticides or fungicides.

And then, the hardest thing has been, when is petal fall?

Growers, when they have honey bees, petal fall is when you take those honey bee hives out.

It could be 20% of the bloom is still left.

When you're relying on wild bees, as we're doing more and more, you've got to be really selective with that petal fall spray, 'cause you can wipe out everybody, and most of the pollinators for tree fruit are actually univolting, one generation.

So, you wipe them out, there's nobody next year.

And I'll show you, it's more of a, that the orchards are serving as a sanct for pollinators coming in for the landscape in Pennsylvania.

So, everybody knows all the problems with the honey bees.

And they're growing almonds in the desert.

Honey bees, for us, if we have an early season of apples, we have to get all those honey bee hives back out of the almonds in time for the apple bloom.

And the costs have gone quite a bit higher, too, so we kinda started not having a steady source of honey bees for apples in the spring.

And a lot of times, they were what we call "package bees", they didn't have much strength at all anyways.

But we all know there's multiple factors that are in there.

I deal with a lot in trying to minimize the pesticide impacts, but all these other things, like putting them on a semi and shipping them from Pennsylvania to California, that's a pretty stressful thing for them to do.

So, MaryAnn Frazier did a survey, and we basically did these time counts in apple orchards back in 1998, well before colony collapse disorder, and there used to be this kind of rule of thumb that you needed about two to three bees per two-minute count to have enough pollinators, enough honey bees back then, to get adequate pollination.

But we came back ten years later into some of the same orchards, we found the numbers had gone way down, up to a sixfold decline in there.

And it was the same orchards, same trees, and it was partially because the hives were getting weaker, and partially because they were getting so expensive, the apple growers were starting to cut back on them.

So like a lot of other people, when colony collapse disorder came along, we started looking at alternative pollinators, all these wild bees that were probably doing some of the job already.

And I highly recommend this book.

Anything with Xerces, they've been working with bee conservation for decades and there's a lot of precedence for different crops.

Where in the past, they did all the pollination instead of the honey bees.

And there's a lot of diversity, mostly in the East Coast, where we've got complex landscapes, where there's a lot of places from them to nest, and feed on something other than a monoculture crop and trying to get away from the pesticides.

So, I was part of this ICP program, we all started looking at, what can be done if, worst-case scenario, honey bees disappear?

Can we get by with the wild pollinators?

One thing that was different in our crop at the ICP was most people were looking at yields, almonds you're looking at yields, blueberries mostly about yields, in tree fruit you're not looking at yields, you're looking at fruit quality and size.

You can't sell a whole bunch of little marble-sized apples, they won't even buy those for juice.

So, out of all those flowers that are out there at bloom, you only need 2-5% of those to set and have fruit, in apples, to have a full crop.

Anything else you're going to have to spray chemically to thin 'em off, otherwise you'll have too small a fruit that you can't sell.

Same thing with peaches, a little bit higher, but only 5-8% of those.

So the pollination requirements are not that high for our tree fruit in the east area.

If we can just get that amount, we're good, we don't have to pay extra, in peaches they actually have to pay for labor, to hand trim them, so you have one peach every four to six inches of branch and the biggest cost for fruit growers is actually labor.

We probably had more than we needed with all these honey bee hives out there as well.

Now, if you're looking at yield, like we look at cherries, you need at least 80% of those blossoms to set, so, whereas we have a lot of peach growers and apple growers I'll talk about in a second that don't use honey bees, we always put honey bees out there in the cherries, cause it's all about yield.

And then we have a really good example of how wild bees have been doing it for a long time, in that we have peaches, we have about 4,000 acres of peaches in Pennsylvania.

Peaches are wind pollinated, they don't need bees, but in anybody that thought they needed bees, they thought, well it's the feral honey bees.

Well colony collapse disorder killed all the wild honey bees out there and growers have not been using the honey bees in peaches for 50 years.

We also had a number of fruit growers that had not used honey bees in apple orchards, like 1000 acres at a time, for over 30 years.

So we had some good examples that it was possible.

So with that in mind, I started looking at who is doing the job?

I've gotten over 260 bee species in and around orchards some time during the year.

We're getting quite a bit of diversity and I'm also trying to set a baseline as to whether or not reducing pesticides is actually increasing bee diversity and abundance in these orchards as we get away from some of the practices we know that were harmful to bees.

And of these, it's nice to have redundancy, and we have 50-60 species that are out there every year so one year they're really super abundant, the next year they may be gone, small bees don't forge very far from the edge of the orchards, bigger bees do.

And they kinda take over, it's kinda ecosystem functioning, that they can compensate for the natural cycles in certain populations.

So I'll talk a lot about Osmia cornifrons, which is the Japanese Orchard Bee, but to me it's just one of 50 or 60 species that are out there doing the job.

We kinda have some interesting general keys for the different bees that are out there, but if you look at page nine on this, you'll see a very nice graph that we have, that shows basically the phenology of tree fruits.

You start out with apricots, you go to plums, peaches, cherries, and then you end up with apples.

And the best bee populations are always in the diversified farms that have all of these crops cause they got a smorgasbord to feed on for four to five weeks.

If you're only an apple farm, you only got seven to 10 days of bloom, and then you've gotta find something else to eat.

So we've got a nice situation here, and we've got an idea what other trees to plant to help supplement that if you're only growing apples.

And the only reason we can get buy with mostly wild bees is this Japanese Orchard Bee was introduced by USDA ARS about the late 80s.

And has been shown that one of these Japanese Orchard Bees females will set 2500 apple blossoms in a day.

Honey bee kinda gets out of bed late and it's not that terribly efficient cause it's whetted down the pollen, it only sets 50.

And the Japanese Orchard Bee, having that big, hairy scopa there that transfers 100 times more pollen, will do it in a single visit, but honey bee has to go to that same flower twice.

So on a bee-to-bee basis, they're like 80-100 times more efficient.

And we've also done some work in cherries to show that we can double the yield of cherries because they're such efficient pollinators over honey bees.

Blue Orchard Bee, I get a lot of grief, why aren't you working with a native bee?

It's like well, anybody know what the only native tree fruit crop is in the US?

Pawpaw. Which is fly pollinated.

So if you want to get really good pawpaw pollination, hang dead fish from the branches and then all the flies will come in and pollinate them.

So, Osmia in general are very well adapted to rosacea, but they're really well for the rosacea crops.

And in the East Coast, the Blue Orchard Bee is a different subspecies here, it doesn't do nearly as well.

And these guys all nest in preexisting holes that were made by beetles in dead trees and stuff, and Osmia cornifrons, the Japanese Orchard Bee, will nest in any hole from five millimeters up to 12.

But the Blue Orchard Bee is really picky, it only wants eight millimeters and I think it's just a little more adaptable to the local habitat.

These guys will also fly out there earlier in morning, they'll go out in a light rain, there's a lot of advantages to some of these bees.

And this is, I raised 25, 30,000 of these Japanese Orchard Bees every year and these nest containers, they're very efficient, but they only fly about 40-50 yards which is okay in apple orchards, because if you fly into your neighbor's orchard and he has fire blight, which is the disease that kills the apples, they will bring it back to your orchard.

A bee that doesn't fly that far is not a bad thing and especially if the neighbor is using really nasty pesticides, they're not gonna bring it back into your orchard as well.

And this is some of the work we did, just real, to show you, where we marked the bees and we actually went back to the same trees and showed we could double the yield of the cherries.

In orchards without honey bees.

There's a bunch of formulas talking about how far they forage, but if you put a Japanese Orchard Bee nest in the middle of a cherry orchard, it doesn't need to fly very far, it can fly hundreds of yards away, but if it's got all the food it wants, it only flies about 40 or 50 meters.

So, basically we wanted to know, if we were going to replace the honey bees, how many of these hives do we need, we only need 250 females to replace 10-12,000 honey bees, but we need one of these every acre.

And it's surprising how many insects are out there that want to either eat the bee or steal the bee's pollen or kill the bee's larvae and then eat the pollen.

There's a lot of parasites out there so wild bees come with their own problems too, like these are Japanese Orchard Bees, they're covered with these mites to the point that they can't even fly, they use the same nest material and they will get in there and they will transfer from cell to cell and will eat all the pollen before the bee larvae can eat it.

So there's some management practices we've had to do with Osmia as well.

Pesticide impacts being one of them, other people who are thinking about Osmia too, as a test subject, the only thing is Osmia doesn't really sting much, they only lay about 30 eggs, but they started to raise them in Italy where people live with allergies to honey bees, the kids and stuff like that, they can't have honey bees there, Osmia don't fly far, they're really hard to get you to sting, they're really safe to use in situations like that, and for crops that have really low sugar content, like Asian pears and pears, where honey bees will go to anything but them, the Japanese Orchard Bees probably have a very good fit commercially, cause they just want the pollen.

Okay, a lot of the stuff I do with Xerces, this is basically what you need for any bees that are out there.

Food, hopefully you got more food then just on those almond trees for 10 days, nest sites, that usually comes from the outside, we're not getting a lot of bees nesting in the orchards, still too many pesticides, even though we've cut back, and protection from harmful practices.

So that's a diversified fruit farm that has apricots, plums, cherries, and like that, that's where we see the most diversity.

If you're just raising apples, you're not gonna get quite the diversity, unless you have a lot of good habitat for them to fly in to from the edges.

Like where I grew up in the Midwest, where you don't see a tree for miles and miles.

If you have a habitat like this, and no place for them to nest, no alternative food, you better be using honey bees.

But we have a very good situation in Pennsylvania, where our orchards are relatively small on the sides of mountains.

There's a picture down there by the station.

To where we've got, you know, plenty of habitat for them to fly in.

If you look at Adams County, which is actually the most apple acreage in all of the United States, including West Coast, we have 22,000 acres of apples in Pennsylvania, and about 8% are in Adams County, and 56% of it is forest, because they raise 'em on the side of mountains.

A south-facing slope, whereas in Michigan and New York they raise 'em next to the lakes for frost protection.

We raise 'em up high and we raise 'em small and if you look at a typical orchard, there's all these nice fencerows and woods all surrounding that they can't put anything else cause it's really steep and we have this really poster child count of, as Xerces says, situation for complex habitat where there's a lot of alternative food and nesting habitats.

So we're really well set up, there's some positive news here that we've actually got a really good situation.

That we do not want to go away.

So we started looking at different zones cause we were worried, the further you go away from the woods, where's the breaking point where you can't rely on wild pollinators?

Remember some of them are really small, don't fly very far, but the proof is when we harvest we get a markable crop with a good yield, enough seeds, apples typically have 10 seeds inside them, the thought was you have to have all 10 seeds to get a really nice well-shaped apple, but we're finding certain varieties like honey crisp, you can get by with no seeds or only one seed, it all depends on the fruit load and the chemical thinning as to whether or not they stick around there, so it's a little bit more of a complex issue.

But basically we were testing out to 200 meters, which is about the furthest distance you can get for most of ours.

And you see here with the honey bee, you know, it basically doesn't matter to them, if you put all 22,000 acres in a big circle in Pennsylvania of apples, put a honey bee in a hive, you could be assured that it was not foraging outside that orchard, they fly that far.

Whereas bumble bees are not quite as far, but there's a lot of them and they fly a fairly good distance.

It's the solitary bees I was worried about.

As we got to 200 meters, you definitely see a decline in the numbers.

But is the decline enough so that we're not meeting that 2-5% out there at 200 meters.

In general, we really didn't see too much of a real response, you know, out to 200 meters, we got enough fruit with enough seeds, they had a commercial crop.

And the guys have been doing this for 30 years, on thousands of acres, were right, they can get by without the honey bees.

So we're pretty sure at this point, out to 200 meters, which is most of the orchards, as long as you got good habitat around there, you can get by without the honey bees on apples and peaches, not cherries.

And they other thing we got out of this is this is the biggest block I know around in Pennsylvania, it's 100 acre block.

Instead of putting 200 honey bee hives out here, well, look at the gaps where the wild bees can't get.

You can out your honey bee's hives a little more strategically here so that they wild bees are covering the edges, but you're putting your honey bee hives in a better place.

The other thing is this is where your pollination gaps are if it's more than 200 meters, maybe this is where you should put your pollinator strips and your habitat.

So the upshot of this after about 10 years is that most of our apple growers, in Pennsylvania and New York, no longer use honey bees, we're relying on the wild bees.

And at $125 per hive, and two hives per acre, a grower with 100 acres is saving about $20,000 a year.

Bottom line is they're also business men, so we had to show them that there was an economic benefit to this.

So again, low pollination requirements compared to some of the other crops, we were looking at yield.

We finally got smart and went to something a little more high tech, but we put in about 300 acres total and this makes really good sense where you've got those gaps where there's no fencerows or wood lots around there to give them nesting sites and then additional food.

We had a lot of growers interested, we found out basically the stuff that was being planted, most pollinator strips really didn't help the tree fruit much cause they bloomed too late, they bloom after apple bloom.

It helps things like bumble bees that have multiple generations, but those univolting species, they could care less.

But we came up with these NRCS recommendations for Pennsylvania, both for cover crop alternative species and there's a list of 'em.

And also we're going more towards pollinator hedge rows, woody plants, that bloom early, like Red Maples, and things like that.

They're more useful.

So most of our Pennsylvania growers are really not using honey bees, at least in apples, I know they have that requirement, they never use that in peaches.

Maintaining the fencerows, the efforts we're doing with NRCS at this point are paying growers to not take out that fencerow, not take out that wood lot.

And realize there's a value to it and hopefully work together some models of the, that'll actually put a value on that.

And consider bees with pesticides cause if you're relying on wild bees, you've gotta be a lot more concerned then, is the box in the orchard or out of the orchard?

A lot of different funding agencies.

Just wanted to put a plug in for Xerces, we do a lot of work with them, they've been around forever.

They are the one stop shopping guide for most of the regional requirements.

You go to their website, you'll find all these resources available, they're also embedded within NRCS.

And those of you not familiar with NRCS, I joke with farmers that they put their money where my mouth is.

This basically pays for 80% of the perceived costs if I work with them.

I don't get any money out of it, but it's a way to implement really good ideas and get it out there and they're really in there for anything that will have an environ, save pesticides, environmental concerns.

And Xerces has a whole series of guides, most of them are available online free as PDFs.

A very good book as well, which I didn't, couldn't find my copy of, I would highly recommend getting to the Xerces website.

And they have these regional plant lists that are basically for each of the regions, very very useful.