The Decline of Pollinators

The Decline of Pollinators

Part of Ep. 1902 Bees, Trees, & Pears Please

UW-Extension Entomologist Phil Pellitteri shows us why bees and other pollinators are declining and what we can do to help.  Without pollinators, some crops won't bear fruit.

Premiere date: Apr 27, 2011

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley Ryan:
I am with UW-Extension entomologist Phil Pellitteri.  We’re in his backyard in what feels today like downtown Madison.  We are talking about the decline of pollinators.  Phil, I was surprised.  I guess I thought of honey bees as our main pollinator. 

Phil Pellitteri:
Shelley, really even in the bee group, there’s three groups that we talk about.  The honey bees are probably the ones people are most familiar with.  Bumble bees are very important.  But then you take the next step.  There are over 400 species of bees alone that are pollinators. 

Shelley Ryan:
Really? 

Phil Pellitteri:
They’re not the only pollinators.  We have wasps.  We have moths.  We have other beetles that play into it.  But bees are basically the most important. 

Shelley Ryan:
There’s an overall decline of all of them. 

Phil Pellitteri:
Yeah, and for different reasons.  Honey bees have had problems with a couple parasitic mites and diseases that have moved in and caused major declines.  We basically lost about 30% of our colonies. 

Shelley Ryan:
Wow. 

Phil Pellitteri:
Compared to about three or four decades ago.  One of the relatively new things to come on are bumble bee declines.  Although we have 18 species of bumble bees in the state, and some of them have suffered because of habitat loss.  But in the last ten years, there have been major declines that we think are associated with some new diseases that have moved in.  Unfortunately, we suspect that these diseases have come in from bumble bees that were imported from Europe for greenhouse pollination, and we brought some European diseases in, and they’re causing problems. 

Shelley Ryan:
They got let loose from the greenhouses and they’re out here now. 

Phil Pellitteri:
Right. 

Shelley Ryan:
We need to mention why pollinators are so important.  We wouldn’t have apples without pollinators.  Squash. 

Phil Pellitteri:
Basically they’re responsible for about a third of what we eat is directly related to pollination.  We’re talking apples, cucumbers, strawberries.  In some cases, it makes the crop bigger, some cases, totally dependent, without ‘em, we don’t have a crop. 

Shelley Ryan:
So we have to do something about it. 

Phil Pellitteri:
What we’re looking at now really are promoting native colonies.  Like I said, we have over 400 species in this state, and those are things to look at.  Some of them are ground nesters.  To be honest, leaving bare patches of soil is really very beneficial for them, because those are the things they utilize.  They will go out and collect pollen.  They put it in these tubes that they dig into the ground, lay their egg, and then have nothing else to do with it.  We call these solitary bees.  That’s one type that we work with. 

Shelley Ryan:
So often, I hear from people, I saw bees coming out of the ground, I’ve got to kill them. 

Phil Pellitteri:
If they’re solitary bees, there’s really no true nest.  Anything that doesn’t have a nest is not going to be very aggressive.  One of the other bees that we see that people I think for the most part recognize, are bumble bees.  Bumble bees are also ground nesters.  They particularly use old rodent burrows, those kind of things.  These are very beneficial.  In fact, some things, like tomatoes are totally dependent on bumble bees for pollination.  What they mistake these for are ground nesting wasps.  But a real simple thing is, if it’s fuzzy, it’s a bee.  If it doesn’t have lots of hairs on the body, then it’s more likely a wasp.  The difference is wasps are predators, they feed on other things.  Sometimes they scavenge on things, and that’s what gets them in trouble with people. 

Shelley Ryan:
They can be aggressive.  So, these are the guys we want, if we see them in the ground, leave them alone. 

Phil Pellitteri:
Just stay clear, because you don’t want to threaten the nest.  If you threaten a colony nester, that’s a problem. 

Shelley Ryan:
If you want tomatoes, really leave them alone. 

Phil Pellitteri:
Another thing you can do, is there’s a large number of these species that nest in basically straw-like environments.  This is an artificial house that was put together basically for mason bees.  It’s a very popular bee, because it’s active very early in the spring when things are cool.  What they do, is they use this straw-like environment. 

Shelley Ryan:
These tubes, basically? 

Phil Pellitteri:
Tubes, yes.  Mason bees have a 3/8" diameter hole, but if you make the holes different sizes, what you do is provide habitat for a number of different species. 

Shelley Ryan:
You’ve got different sized holes in this.  Different bees are cohabitating, basically? 

Phil Pellitteri:
Oh, yeah, definitely.  No problem at all.  Again, they’re not aggressive.  This is not really a nest, per se, when we think of the way a colony bee works.  So there is no problem.  The other interesting thing is some of the bee species don’t even sting. 

Shelley Ryan:
Wow, okay.  We can make this.  I’ve also seen mason bee houses for sale.  There’s lots of ways. 

Phil Pellitteri:
People even take straws, a bunch of straws, bind them together and put that out.  In nature, they’re using the hollow pith plants, and those things, for habitats.  You’re providing the same thing, and that would work, too. 

Shelley Ryan:
Then as far as what we gardeners can do besides providing houses and leaving bare patches of dirt, like butterfly gardening, are there things we should be planting? 

Phil Pellitteri:
A lot of native plants.  You want to have flower sources all season long, so they have food, both pollen and nectar.  That’s basically what they’re going to be utilizing.  The other thing is to leave some wild areas, because those are often, again, the kind of habitats where these bees will find.  The plants, which some people might define as weeds at times, but really, weeds flower too, so they’re very important as far as these things are concerned.  It also, again, will provide the kind of habitat that they can raise their young in. 

Shelley Ryan:
Then they should love my yard.  Thanks, Phil. 

Phil Pellitteri:
Sure.  Shelley Ryan:
I am with UW-Extension entomologist Phil Pellitteri.  We’re in his backyard in what feels today like downtown Madison.  We are talking about the decline of pollinators.  Phil, I was surprised.  I guess I thought of honey bees as our main pollinator. 

Phil Pellitteri:
Shelley, really even in the bee group, there’s three groups that we talk about.  The honey bees are probably the ones people are most familiar with.  Bumble bees are very important.  But then you take the next step.  There are over 400 species of bees alone that are pollinators. 

Shelley Ryan:
Really? 

Phil Pellitteri:
They’re not the only pollinators.  We have wasps.  We have moths.  We have other beetles that play into it.  But bees are basically the most important. 

Shelley Ryan:
There’s an overall decline of all of them. 

Phil Pellitteri:
Yeah, and for different reasons.  Honey bees have had problems with a couple parasitic mites and diseases that have moved in and caused major declines.  We basically lost about 30% of our colonies. 

Shelley Ryan:
Wow. 

Phil Pellitteri:
Compared to about three or four decades ago.  One of the relatively new things to come on are bumble bee declines.  Although we have 18 species of bumble bees in the state, and some of them have suffered because of habitat loss.  But in the last ten years, there have been major declines that we think are associated with some new diseases that have moved in.  Unfortunately, we suspect that these diseases have come in from bumble bees that were imported from Europe for greenhouse pollination, and we brought some European diseases in, and they’re causing problems. 

Shelley Ryan:
They got let loose from the greenhouses and they’re out here now. 

Phil Pellitteri:
Right. 

Shelley Ryan:
We need to mention why pollinators are so important.  We wouldn’t have apples without pollinators.  Squash. 

Phil Pellitteri:
Basically they’re responsible for about a third of what we eat is directly related to pollination.  We’re talking apples, cucumbers, strawberries.  In some cases, it makes the crop bigger, some cases, totally dependent, without ‘em, we don’t have a crop. 

Shelley Ryan:
So we have to do something about it. 

Phil Pellitteri:
What we’re looking at now really are promoting native colonies.  Like I said, we have over 400 species in this state, and those are things to look at.  Some of them are ground nesters.  To be honest, leaving bare patches of soil is really very beneficial for them, because those are the things they utilize.  They will go out and collect pollen.  They put it in these tubes that they dig into the ground, lay their egg, and then have nothing else to do with it.  We call these solitary bees.  That’s one type that we work with. 

Shelley Ryan:
So often, I hear from people, I saw bees coming out of the ground, I’ve got to kill them. 

Phil Pellitteri:
If they’re solitary bees, there’s really no true nest.  Anything that doesn’t have a nest is not going to be very aggressive.  One of the other bees that we see that people I think for the most part recognize, are bumble bees.  Bumble bees are also ground nesters.  They particularly use old rodent burrows, those kind of things.  These are very beneficial.  In fact, some things, like tomatoes are totally dependent on bumble bees for pollination.  What they mistake these for are ground nesting wasps.  But a real simple thing is, if it’s fuzzy, it’s a bee.  If it doesn’t have lots of hairs on the body, then it’s more likely a wasp.  The difference is wasps are predators, they feed on other things.  Sometimes they scavenge on things, and that’s what gets them in trouble with people. 

Shelley Ryan:
They can be aggressive.  So, these are the guys we want, if we see them in the ground, leave them alone. 

Phil Pellitteri:
Just stay clear, because you don’t want to threaten the nest.  If you threaten a colony nester, that’s a problem. 

Shelley Ryan:
If you want tomatoes, really leave them alone. 

Phil Pellitteri:
Another thing you can do, is there’s a large number of these species that nest in basically straw-like environments.  This is an artificial house that was put together basically for mason bees.  It’s a very popular bee, because it’s active very early in the spring when things are cool.  What they do, is they use this straw-like environment. 

Shelley Ryan:
These tubes, basically? 

Phil Pellitteri:
Tubes, yes.  Mason bees have a 3/8" diameter hole, but if you make the holes different sizes, what you do is provide habitat for a number of different species. 

Shelley Ryan:
You’ve got different sized holes in this.  Different bees are cohabitating, basically? 

Phil Pellitteri:
Oh, yeah, definitely.  No problem at all.  Again, they’re not aggressive.  This is not really a nest, per se, when we think of the way a colony bee works.  So there is no problem.  The other interesting thing is some of the bee species don’t even sting. 

Shelley Ryan:
Wow, okay.  We can make this.  I’ve also seen mason bee houses for sale.  There’s lots of ways. 

Phil Pellitteri:
People even take straws, a bunch of straws, bind them together and put that out.  In nature, they’re using the hollow pith plants, and those things, for habitats.  You’re providing the same thing, and that would work, too. 

Shelley Ryan:
Then as far as what we gardeners can do besides providing houses and leaving bare patches of dirt, like butterfly gardening, are there things we should be planting? 

Phil Pellitteri:
A lot of native plants.  You want to have flower sources all season long, so they have food, both pollen and nectar.  That’s basically what they’re going to be utilizing.  The other thing is to leave some wild areas, because those are often, again, the kind of habitats where these bees will find.  The plants, which some people might define as weeds at times, but really, weeds flower too, so they’re very important as far as these things are concerned.  It also, again, will provide the kind of habitat that they can raise their young in. 

Shelley Ryan:
Then they should love my yard.  Thanks, Phil. 

Phil Pellitteri:
Sure. 

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