Farming for Beneficial Insects: Pollinators, Predators and Parasitoids


And with that, I’m going to turn
over the introduction of today’s topic and speaker to
our guest moderator, Sudie. Thanks, Holli. Like Holli, said, my name
is Sudie Thomas. I’m a wildlife biologist in
South Carolina for the Natural Resources Conservation Service,
and I just want to say a little bit about NRCS in
case people aren’t familiar. We are a federal agency
operating under the umbrella of the USDA, the Department
of Agriculture. We’re one of the agencies
charged with facilitating Farm Bill conservation programs. And these programs assist
private landowners and other clients in conserving,
restoring, and protecting natural resources. A few examples of the natural
resources targeted for conservation are soils, usually
in agricultural settings, wetlands, and
wildlife habitats. More recently, much focus
has been turned towards beneficial insects. And NRCS now emphasizes the
protection of and habitat enhancement of beneficial
insects through Farm Bill programs and conservation
practices. In that effort we work closely
with the Xerces Society to promote beneficial practices,
pursue further investigation into the potential impact of
conservation practices, and to educate landowners and the
general public through workshops, publications,
and training sessions like this one today. So today I get to introduce
Nancy Lee Adamson, who’s going to be your presenter. She is a pollinator conservation
specialist, and she really works double duty. She works jointly for the
Xerces Society for Invertebrate Conservation, and
she also works with the NRCS East National Technology
Support Center. So everyone is in for a treat,
because Nancy always presents a lot of useful information
about farming for beneficial insects. She has a lot of experience and
knowledge on the subject and you will see that she is
pretty passionate about beneficial insects
and pollinators. I had the pleasure of working
with Nancy in workshops in South Carolina, where
I learned a lot. So if you ever get a chance to
get out in the field with her, you’re going to learn a lot
about insect ID, plant ID, and habitat enhancement. So here is Nancy on the
subject of farming for beneficial insects and the
conservation of native pollinators, predators,
and parasitoids. Hello, everyone. Thank you so much for
joining us today. And I want to thank Holli
for heading this up. And for Sudie helping
to moderate. She has a big task trying
to coordinate all the questions coming in. Everything she said about me in
the field is true of her. If you go out in the field,
you’ll learn a ton. So thank you. All righty. Well, just a little
introduction to the Xerces Society. Xerces has been supporting
insects and other invertebrates, which includes
mollusks and crustaceans and other animals without backbones,
for 40 years. We take our name from the first
butterfly to go extinct in the US due to human
activities, the Xerces blue butterfly. So we do all sorts of work to
support invertebrates, but a big part of our work is
pollinator conservation. We work closely with the USDA
Natural Resources Conservation Service, and thanks, Sudie, for
that introduction to NRCS. USDA has always supported
pollinator conservation. The 2008 Farm Bill responded
to widespread concerns over pollinator declines, especially
Colony Collapse Disorder, which really brought
home the pollinator and pollination crisis. So both Farm Bills–we don’t
have the 2013 quite yet, but hopefully the new bill is going
to include pollinators in all USDA conservation
programs, as well. Mace Vaughan and Eric Mader,
the heads of the Xerces pollinator program, recently
reviewed NRCS programs that can be used to support
pollinators. The program is a little bit
longer, 90 minutes instead of 50 like today, and includes
lots of details on plants. So even though it’s oriented
towards NRCS staff, I think it would be really valuable for
anybody interested in habitat conservation. And there’re several other
webinars online. If you’re interested in bees,
there’s one on common bees and best bee plants of the east. I am in the East National Tech
Center, so for those of you in the midwest and the far west,
my experience is more in the east, just so you know that. The NRCS is able to help
pollinators through habitat development and helping growers implement IPM practices. IPM is Integrated Pest
Management, and I’ll talk about that a little
bit more later. I know most people are pretty
aware of what that is, but IPM helps reduce the need for and
non-target impacts of pesticide application. These same practices are vital
for supporting other beneficial insects, such as
predators and parasitoids, that help control
pests on crops. We also call them natural
enemies of pests. So wasps, spiders, some flies,
beetles and bugs are predators eating other insects. Parasitoids are parasites
that kill their hosts. We use the term parasitoid–they
are parasites, but most parasites
don’t kill their host. Parasites tend to be much
smaller than their host, while many parasitoids are about the
same size as their host. Just one other little thing. Most of the day today, we’ll
be talking about beneficial insect plantings, but
those are also called insectary plantings. Today we’re taking a look at
the value of diversity in agriculture and at benefits of
arthropods and nematodes. So arthropods–technically,
spiders aren’t insects–include spiders
and insects. Then we’ll take a look at ways
to support them with habitat, food, shelter, and protection
from pesticides. We’ll see how much time we have
for establishment and long term management, and
then a little bit on additional resources. Biological farming is another
name for sustainable farming, but the phrase biological
reminds us to take advantage of natural processes and
relationships to improve management. Increasing diversity on a farm
has a lot of associated benefits, which include reduced
herbicide use, lower pesticide use, and more
nesting opportunities. We’ll look at a few examples
shortly of specific ways diverse habitat supports
beneficial insects to improve farm production. Organic producers, who tend to
have diverse farms to begin with, are required to enhance
biodiversity on their farms. Adding pollinator and other
beneficial insect habitat is a good way to add even more
diversity and further promote ecological balance. Some farms may find that simply
advertising no or reduced pesticide use and
knowing their customers is as important as organic
certification. In North Carolina and other
states, Departments of Agriculture are encouraging
communities to support local economies and farmers by buying
locally grown produce. In tandem, agri-tourism helps
people connect with farmers, understand why local produce
can sometimes be more expensive, and perhaps increase
their willingness to pay a little more up front. The local produce prices may
not be that different from produce shipped in. At a sustainable agriculture
meeting in Virginia, a farmer shared his conviction with an
audience filled with young people that this buy local
movement was here to stay, not a short-lived trend, but part
of increasing awareness that we all have a role in building
strong local communities, communities that are more
resilient through economically rough times. Field borders and hedgerows
designed to support beneficial insects can also add flower
power in terms of beautification and income from
cut flowers or berries. Other benefits of planting for
beneficial insects include protecting watersheds and
providing wildlife habitat, especially species needing
open, early successional habitat, such as many
ground nesting birds, grassland birds. The more diverse the planting,
the greater the insect diversity, which means
better diets for all sorts of wildlife. We’ll be focusing on wild
natural enemies and native pollinators. Insects, in general, are vital
to all of us: at the base of food chains, they sustain
our ecosystems. How we treat insects has a
direct impact on other wildlife, our watersheds,
and our well-being. Insects are just as good a food
source for other insects as they are for birds, mammals,
and other wildlife. As many of you know, these are
cocoons of parasitic wasps that, as larvae, feed on the
insides of this hornworm. They are nearly ready to emerge
as adult wasps, tiny and ready to mate and lay
eggs on other hornworm caterpillars. Taking advantage of
relationships between pests and their natural enemies to
improve farm productivity means rethinking
insect control. In any predator-prey system,
whether it’s wolves and rabbits or wasps and hornworms,
if we wipe out both populations in one fell swoop,
it takes predators a lot longer than pests to return
to that ecosystem or agricultural field. Many insecticides kill not only
pests, but the predators and parasitoids that
help control them. Adding field borders, diverse
hedgerows, leaving areas fallow or maintaining natural
areas close to farmland provides refuge for beneficial
insects so they have food, resources and shelter when the
crop site is barren, and can recolonize the next crop
that is planted. Conservation biological control
is part of integrated pest management– and I talked about that
a little bit– managing farms in an integrated
way to reduce pest pressure, monitoring levels of
pests or pest damage, not just spraying on a set schedule
regardless of pests’ presence. Predators and parasitoids are
sometimes called beneficial insects, sometimes natural
enemies, with “of pests” implied, or biological
control agents. Beneficial insects also
include pollinators. While many crop pests are
common across our landscapes… ..a lot of biological
control is very regionally or locally specific. Extension is often the best
source for locally relevant biocontrol information. And I’ve put up the eXtension
website here. That’s a national cooperative
effort among extension across the country. When you go there, if you type
in conservation biological control, it generally
will bring up resources in your region. But also, each agricultural
university has an integrated pest management program, so
they’re really the best source of what’s currently known. There’s lots of new research
in this area. It’s a really exciting part of
entomology because of all the good things associated with
reduced pesticide: lowering costs and improving
pest management. Biological control is not
aimed at eliminating all pests, but maintaining a healthy
ecosystem so pest pressure remains below
economic thresholds. Even though you see insects in
your field or in your garden, or you might see quite a bit
of damage, for instance, to leaves, there can be a good
bit of herbivory sometimes without it actually affecting
production. In agricultural systems we’ve
actually come up with economic thresholds to understand when
that insect damage is reaching a level that’s going to
affect the bottom line or affect the harvest. It’s actually surprising
sometimes how much damage there can be without
having an effect. When we’re talking about using
biological control, it’s just to slow pest population
growth rates. Again, if both predator and prey
are wiped out, it takes predators much longer
to recover. I also wanted to mention that
Xerces Society worked with NRCS to develop this
conservation biological control tech note that will
be out later this summer. It’s in draft form now, and
there will be a webinar on August 29 that is highlighting
integrated pest management and taking a closer look at
this document itself. So tune in again. It’ll be on this same conservationwebinars.net website. We have a pretty good idea of
the value of natural enemies for crop production. But as you can see
in this photo– and maybe you can’t see, it’s
so tiny–a lot of these parasitoids, in particular,
are easy to miss. The mottled tortoise beetle,
here, is a sweet potato pest smaller than the tip of my
pinkie, so this little wasp is pretty minute. As in any predator-prey system,
pests repopulate a crop more quickly
than predators. Spiders are generalist
predators, so in habitats without crop pests, pollinators
make a good feast [referring to photo]. Parasitoids are parasites that
kill their hosts and are often specialists. If you like that ???biological
control agent??? terminology, you might call these ???special
agents.??? Adult predatory wasps are
omnivorous, and catch prey to provide to their carnivorous
young. She will lay one egg on this
cicada after placing it in an underground nest. Parasitoid wasps lay
their eggs on other insects, such as aphids. Their larvae hatch, eat their
host, then pupate, usually killing their hosts. Some larger wasps are
also parasitoids. Scoliid wasps paralyze and lay
eggs on white grubs, such as June beetle or Japanese
beetle larvae. As adults, they consume
pollen and nectar. Many parasitoid adults feed on
nectar and pollen, though their young may specialize
on certain species. This adult syrphid fly is a bee
mimic, feeding on pollen. It’s young, this little fly
larva, smaller than the aphid it’s eating, is a voracious
predator. Flies overwinter in leaf litter
or in the soil, so it’s important to maintain
undisturbed natural areas adjacent to farmland
to support them. Many predatory flies
mimic bees. Though we know some fly
bites are painful, flies don’t have stingers. Prey may not expect what they
see as a bee on a flower to be dangerous or aggressive. Beetles overwinter in leaf
litter, soil, and rotting woods, so having some
undisturbed natural areas near agricultural fields can help
in maintaining populations. They overwinter in leaf litter,
soil, and rotting wood, so same story. Some natural area is
really good support close to the farmland. Lacewings are predaceous
as adults and larvae. Lacewing larvae will eat one
another, so lacewings have developed this stalk
for their eggs. Usually there’s half a dozen or
more in a row, and they’re usually not on the fruit. They’re more likely
to be found on the stem or the leaves. So if the larvae hatches from
that egg, it will climb down the stalk, but it tends not to
climb up the other stalks to eat the eggs. If they were all sitting there,
they would eat them up. So here, the green lacewing
larva is eating white fly larvae, just the right size. It can be hard at first glance
to distinguish a pest bug from a beneficial predator bug,
like this assassin bug. Until you start looking for
predators or parasitoids, you may not notice them. So it’s really important to
remember that if there are pests present, chances are
there’s going to be good predatory or parasitoid insects
or other arthropods present, as well. Habitat near crops provides
harborage and food for predators and parasitoids when
crops are harvested. When we’re talking about
pollinators, most of those can fly in and out of the
crop if it’s there. They can go fly someplace
else. But some of our predators,
especially spiders, can’t fly around, so it’s really important
to have that habitat close by. Besides habitat patches,
maintaining soil health can also help reduce pest problems
by supporting healthy plant growth and beneficial soil
arthropods like nematodes. I guess they aren’t
arthropods. They’re in their own group,
the Nematoda. Nursery operations depend on
beneficial nematodes sold commercially to manage fungus
gnats and thrips. This is one beneficial
nematode that gets used quite a bit. We’ll take a few minutes to talk
about the importance of pollinators and their
habitat needs. Since our most important crop
pollinators are bees, most of our pollinator work related to
the Farm Bill is aimed at supporting bees. Native bees are vital for
crop pollination. And here you can see examples
of how many different species we have. But even though we’ve known
how important they are for quite a long time, it wasn’t
really until Colony Collapse Disorder that we’ve realized
that we really have to start supporting them, to make more
of a concerted effort to support them. This research that came out in
2003 looked at the effects of native bees visiting crops
versus honeybees. And they found that in 41 crops
around the globe, wild pollinators, which mostly are
native bees, significantly increased production, versus
only 14% of crops with honeybee visits. In those where fruit set was
improved by both groups, wild and honey bees, wild bees
improved set twice as much as honey bees. This isn’t to diminish the
importance of honeybees. We can’t manage a lot of our
other bees the same way. We can’t bring in tens of
thousands in a day to the crops, so we’re not
diminishing the value of honey bees. The reason that some of our
other bees are more efficient has to do with the fact that
many of them are solitary. Oftentimes honey bees
specialize. If there are lots of sisters
foraging, one group can just forage for nectar, and
other ones might just forage for pollen. In this case, you can see the
honey bee is collecting nectar from this apple flower, so
she’s not going to be particularly effective as
an apple pollinator. Whereas these solitary bees–and
I’ll talk a little bit more about the different
types of bees, but most of our bees aren’t social, so every
trip, they need to collect nectar and pollen–these two
mining bees (or digger bees) are diving in through the top
of the flower to get to the nectar, in this case. In this case, she’s gathering
pollen, but in both cases, they’re going to be a lot more
efficient in terms of apple pollination. They’re going to pick up a lot
more pollen to carry to the next flower they visit. Another reason that behavior
affects pollination is our wild bees, our native bees in
North America, do what’s called buzz pollination. That’s just vibrating
the anthers of flowers to release pollen. Honeybees can vibrate their wing
muscles, but not at the right frequency to release
pollen for those groups of flowers. Those are in the tomato,
Solanaceae family (the nightshade group). They’re the same. And also Ericaceae,
the heath family. Whole Foods market staff
decided to do a little demonstration of how important
bees are for our food. They took out 237 of 453
products, about 52% of the produce items normally
sold at the store. They removed things like apples
and avocados, eggplants and squash. And this is what the shelves
looked like after they removed that. Insects really matter. Despite our increased awareness
of the importance of protecting pollinators,
we’ve recently seen some terrible losses. In addition to the continued
high losses of honeybees shown in this chart, just last month
in June about 37 million bees died in Ontario when corn coated
in a neonicotinoid pesticide was planted. The first day of pollinator
week in Portland, Oregon, trees in the parking lot
of Target were sprayed, apparently off-label, on linden
trees for aphids–so really no need for
any spray at all. The aphids were not going to
be hurting the linden. They sprayed them when
they were in flower. 50,000 bumblebees were killed. We believe it’s the biggest
mass killing of bumblebees that has been documented. Despite our tremendous
understanding of the crisis, we’re still seeing terrible
things happen like this. So it’s not a time to be
complacent about supporting pollinators. I think people really are aware
of these problems now and want to do things to help. If people find out you’ve been
listening to a beneficial insect talk or a pollinator
talk, they’ll probably want to know what you learned. So don’t take it for granted. How can we better support
pollinators? Everything that we do to benefit
our native bees and wild bees is going to benefit
honey bees, as well. And it will also benefit all
of those other beneficial insects we were talking about,
predators and parasitoids. Sometimes I forget to mention
that honey bees–the reason we talk about native bees or wild
bees is that honeybees aren’t actually native to
North America. They were imported during
colonial times. We do have some wild
honey bees. Some honey bees become feral. And we also have a couple other
species that aren’t native that have naturalized. But most of our bees
are native. And as I showed a little bit
earlier, on that earlier slide, we’ve got about 4,000
species of native bees and the greatest diversity
in the southwest. So, sorry to jump
around there. We’ve got three groups
of native bees based on nesting habits. And the reason we like to think
about them in these terms is that when we’re trying
to support habitat for native bees, it’s helpful
to understand their nesting needs. They all need forage and nectar
and protection from pesticides, but their habitat
needs vary a little bit depending on their
nesting habits. The vast majority of our native
bees are solitary, and that means that they don’t
work cooperatively. They don’t have a queen with
daughters working together. They mate when they emerge, and
then the female will make nests for her young. [Excuse me. I have a little bit
of a cold.] Then she’ll collect nectar and
pollen and provision the nest on her own. That’s also one reason that
they’re particularly efficient, because they only
have a short time to do that. Bumble bees are our social
native bees, and they really love any habitat that
would look like it would be good for mice. They actually like to nest in
abandoned mice burrows. Besides providing forage,
conserving brush piles and unmown areas is the best way
to support bumble bees. I usually tell farmers that if
they have a messy corner on the farm–maybe somebody’s been
bugging them to clean that up–all they need to
do is add a sign saying ???pollinator habitat.??? I really can’t emphasize enough
that those messy areas are really important
for conservation. Usually, as long as people know
that unmown areas are intentional, then they
don’t mind them. If they think it’s just not
cared for, then they might worry about it. This is a big issue in terms
of roadside management. Sorry about that (coughing
break). So let’s see. All righty.] About 70% of our native
bees are solitary, ground nesting bees. Hi, folks. I’m sorry I’m muting there
a little bit to cough.] Our ground nesting bees
nest in the ground. They excavate about one or two
or three feet, while out west maybe 10 or 15 feet into the
ground, and their nests look a lot like ground beetle nests. If it’s a time when they’re
active–they’re usually active for probably several weeks,
maybe even a couple months–if you just observe the holes,
you’ll be able to see the females will be in and out
within a few minutes, bringing provisions. About 30% of our native
bees are cavity nesters, or tunnel nesters. They depend on existing
cavities, mostly. We have carpenter bees that will
excavate nests and have big, strong jaws for that. But most of our cavity nesting
bees depend on existing holes. So dead wood and wood-boring
insects, two things that we generally think of that we might
not always want to have, unless you’re a birder,
are really good for our native bees. Sudie, maybe this is a good
time, if there are any questions, we could take
a little break. There’s one question. We’re going to take more
questions at the end, if other folks come up with some other
questions, I’ll be sure and type them in. I have a question from Paul. He’s asking for a recommended
ratio of bee habitat to cropland when you’re creating or
enhancing or setting aside such areas. Paul, we’re going to talk about
amounts of habitat in the next section. So if you still have more
specific questions, let me know at the end, if that’s OK. I have one, since you were
talking about the different wasps and flies. Just from observing pollinators,
I used to look at a flower and say, oh, that’s not
a bee, that’s just a wasp. But now that I’ve learned all
this about beneficial insects, I was just wondering if you
assume most of the wasps and flies are beneficial? Yes. In general, most wasps are
considered beneficial, because they’re going after smaller
insects, and most of our pest species tend to be
smaller insects. And then flies, I don’t know
what percentage are considered beneficial. So that’s a good question. But if you’re an ecologist, you
know that those flies are providing food for other
wildlife, too. In today’s talk, we’re using
the term beneficial pretty narrowly to refer to insects
that are specifically beneficial for crop pests, but
in general, insects are vital for our ecosystems overall. And so sometimes it’s not always
easy to label things as good or bad. Right. Well, we had one more
question, since we’re on the subject. Like yellow jackets. If yellow jackets move into
the messy section of the field, are there ways we can get
something else to move in? Not all wasps are social. Yellow jackets happen to be a
social species, and they’re actually still considered
beneficial. The only time you probably need
to worry about yellow jackets is when they’re close to
your house or if they’re in your yard where you’re mowing. Just like bumblebees, they
have annual colonies. So they start out with
just one yellow jacket in the spring. And it’s just by the end of
summer that they have a colony that is worth defending. So they usually aren’t
aggressive until the end of summer. If you really just don’t like
yellow jackets, that’s probably not a satisfactory
answer, but that’s the story. If you have more questions
about that just email me. I think we’ll go ahead
and move on. Is that OK, Sudie? Fine. All right. Insect diversity and abundance
in crops depends on natural habitat on or close
to the farm. So here is a nice example. It’s an apple orchard, and
there’s a mixture of grassy area and shrubs and trees. Right now we’re just seeing a
native rose is in flower, but I’m sure there’re
other things. The nice thing about this
habitat is, it’s diverse. Having as many different kinds
of niches as possible, there happens to be more hedgerows
in the background, so the diversity is really important. A big question, and this was
Paul’s question, how much habitat is needed? It’s really hard to say. Usually most farmers can’t just
take out good farm land– they end up usually planting
in marginal areas. In this particular study in
Pennsylvania, where they have very large apple orchards and
they depend on honey bees for a lot of their apple
pollination, they looked at areas of the orchard that were
adjacent to???they looked at who was pollinating apples in
areas in the center of those orchards that were farthest from
the edge, and which bees were pollinating in the areas
closest to the edge habitat. They found that native bees
really provided all the pollination service in the areas
closest to the edge. They were able to recommend to
farmers rather than putting honey bees in those edge areas,
if they did feel like they needed to hire honey bees
for pollination, that it was better to put those in the
center of those large areas, and then take advantage
of the edge. Part of the answer to that
question is that bees– based on their size, the farther
they have to travel, the more energy it’s
going to take. At some point it’s not
efficient for them to provision their nest if they
have to travel too far. The closer the crops are to the
natural habitat, the more likely you’re going to have
native bees visiting. So sometimes we like
to say within 500 feet is a good estimate. And then diverse habitat
is best. Studies have looked at natural
enemy and crop pollination by wild bees in different
types of landscapes. The more diverse the
habitat–and I mentioned this earlier, but if you’re
interested in looking at the research, I’ve included some
references???the better. There’s been some really
terrific work by Glynn Tillman down in Georgia looking at using
insectary plantings. Providing sources of nectar or
pollen for insects is called an insectary planting, versus
a trap crop planting. She also used trap crops. Trap crops are when you plant a
crop to attract pest species away from the crop that you’re
trying to harvest for income. They???re a little bit different
than an insectary, where you’re trying to
invite beneficial insects or support them. But in any case, in her study
she looked at this little parasitoid wasp that infests
the eggs of this stink bug. By providing buckwheat as a
source of nectar, she had 2 1/2 times the rate of
parasitization of stink bugs. Really dramatic effects. So here’s the buckwheat, and
here’s a syrphid fly. I didn’t have a picture of that
wasp on the buckwheat. And if you wanted to look at
some of her research, I’ve included a link there. When she added milkweed as a
source of nectar, looking at a different parasitoid. This is a fly, Trichopoda, and
she lays her eggs on the adults or on large nymphs. The larvae will burrow into the
adults or nymphs and eat it rather than the eggs. So it’s a little bit different
way of parasitizing. When she added milkweed as a
source of nectar, she had five times the rate of parasitization
on the green stink bugs–so really, really
dramatic increase in parasitization with just the
addition of cover crops. A lot of times people say,
???If we’re leaving these messy areas or we’re planting
these areas that maybe look messy to me, is that going to
increase pest pressure? Are we going to have more
pests coming in???? Studies have looked at this and
they found that natural enemy populations are higher and
pest pressure is lower in complex patchy landscapes
that have these type habitats???fallow fields, field margins, or wooded habitats. Any kind of natural area
adjacent to the farms. David Orr here in North Carolina
did do some research looking at packaged beneficial
insect mixes. You can get mixes of plants that
are specifically called beneficial insect mixes from
organic seed companies and different companies. Sometimes they include a
lot of annual species. In most of our NRCS plantings,
we plant perennial wildflowers, unless you’re
doing cover crops. But he did find that some of
those mixes included evening primrose, and that that did
tend to invite some moth species that were pests. So he developed his own
mixes that didn’t include evening primrose. One other issue is that,
depending on the farm system, certain wild flowers that we
might want to plant may already be very present in those
areas, or they could present a problem
as a pest plant. So just be aware when you’re
talking to the farmer in certain landscapes if any
species tend to be more aggressive. Sometimes that aggressiveness is
good for establishment, but if it’s also causing any kind of
weed pests, then you don’t want to use that plant. Here’s the study that looked at
how much habitat is needed for beneficial insects, not
just pollination but parasitoids. So in this canola pest control
study, when they had less than 20% of the land– so as long as 20% or more of the
surrounding landscape was a natural area–they had
adequate parasitization of their pests. Notice that the threshold here
wasn’t 100% infestation or parasitization of the
pest species. Just by having about 1/3 of
the pests infected, or parasitized, that was adequate
biological control. The threshold meant that
harvesting the crop would still be profitable. In general, bigger is better,
but most farmers aren’t going to be able to take out
their best farmland to plant these habitats. Oftentimes we’re just
recommending planting areas that are marginal, or instead
of mowing the edges of farmland, letting things grow
up, or incorporating hedgerows into your agricultural systems
or your garden landscape. Providing habitat is not only
just providing diversity and forage and good sources of
nectar and pollen, it’s also protection from pesticides. Sometimes people ask about
planting these circular irrigation systems. They’ll have little corners
that would be good for pollinators. You could just leave those to
grow up, or enhance them with some pollinator plantings. You just have to be aware if
pesticides are being sprayed on that crop, are those going
to affect those patches? If pesticides are sprayed at a
time when those areas aren’t in flower, then that may not
have a detrimental impact. You just have to be aware that
if you are creating habitat, how is the adjacent farmland
being managed? Is that going to support
those insects? I see it’s already about 10 of,
so I’m just going to go through some of this a
little bit quickly. These materials are in a PDF
list of web links that I’ve put together for pollinator
habitat. It does include some
information on biological control. But this document is in that
list and it’s available online, and it’s looking at ways
to reduce bee poisoning. Its being updated to include
some information on more native bees. A big issue that people often
are concerned about are neonicotinoids, and those are
the ones that I talked about a little bit earlier. I have a good bit more
information about neonics. If you download the
slides, there’s text with all of these. And the main thing is that
neonics are systemic insecticides, so that
means that they’re taken up into the plant. They become part of the plant. So every part of the plant has
these materials in it. If bees are consuming nectar or
pollen, if there’s just a small amount of residue, it
can still affect them. Large doses are lethal, but
small doses do affect foraging and other things, learning
behavior. So these are things
that we recommend. Avoiding application during
or before bloom. Avoid repeated use. These have a very long life, so
they might still be active after three years. Repeated use annually can
really increase levels. And then, do we really need to
use these things for getting rid of aphids on linden trees? I don’t think so. There’re organizations like Bee
City USA who are trying to work with municipalities and
communities to plant native plants and reduce pesticide use
in areas where there’s no agricultural need. So that’s called cosmetic
or ornamental use. A lot of homeowners don’t
realize that the products that they’re buying have
neonics in them. We have a report, and
that is listed here. You can download that. That’s also in the list of web
links that are provided with the webinar. It looks at what we know
about neonicotinoids. So I tend to work a lot with
sustainable or organic farmers, and there seems to be
a little bit of disconnect. Sometimes people think that
because it’s organic, that it’s not toxic. And so this is a real place
where NRCS staff can help people remember that just
because it’s organic, it still is toxic to bees. And there’s lots of different
options that people use that are not really insecticides,
but help control pest problems. So these are some things. I’m not going to go into a lot
of detail here, just for the sake of time, so we can have
a few more questions. One thing for ground nesting
bees, a lot of organic farmers use tillage to help
control weeds. We encourage them to just
avoid deep tillage. Reduce tillage as much
as possible. If you do need to till, if you
can just do it lightly on the surface then you’re going to
have much less of an impact on ground nesting bees. Lots of other alternatives. I have a little section
here on habitat. The main thing I want to talk
about is that bees, in general, have longer tongues
than most of our flies and wasps. If you are interested in
supporting beneficial insects, some of that plants like
mountain mint that have smaller flowers are especially
good for all insects. Bees love them, too. All the NRCS programs require
plantings that include three plants that bloom in the spring,
three that bloom in summer, and three that
bloom in the fall. We want to provide forage
throughout the growing season. Diversity just increases insect
diversity, and that’s good not only for
other beneficial insects, but all wildlife. You’re going to improve the
diet of other critters. And then I have some
establishment tips here, and you can read those later
if you want to take a look at that. The one thing people always are
talking about, if you’re supporting wildlife, and these
beneficial insects are the same, once we have an
established area, or we have a managed natural area, we don’t
want to disturb any more than 1/3 a year. But that can be hard in areas
where there’s high rainfall, so I try to encourage people
to not disturb any one area at one time. You might mow one spot in the
early spring and then another area a little bit
later in spring. You probably don’t want to mow
during ground nesting bird season, so maybe again at the
end of summer mow another little patch. Just spread out if you need
to mow every year due to equipment or just because
you have really fast growing trees. Spread out disturbance through
the whole season. Again, we have this terrific
Conserving Pollinators While Addressing Other Resource
Concerns [webinar] that was a presentation that
Mace and Eric did, if you’re interested in learning more
about NRCS programs. It’s a great program on habitat
in general, so I think it’d be worthwhile, even if
you’re just interested in habitat for wildlife. This is an example. NRCS supports integrated pest
management, and the practice they use is numbered 595. In order to learn more about
this, you would want to visit your local district
conservationist. Just like extension has
extension agents, in NRCS the local person that you would
deal with is the district conservationist. You could go to the main website
to find out in your state and in your county who
is that person and make an appointment with them to learn
more about programs. Even if you don’t need financial
assistance for any of our conservation programs,
you can still get lots of really fantastic technical
assistance. These are some of the resources
that you can get through USDA-NRCS, and I include
links to this in that PDF web links that will be
posted with the show. Xerces has a ton of publications
online. We have a whole website
dedicated to conservation biocontrol, and so I’ve included
that link here and on the PDF web links.
926
00:54:57,250 –>00:54:59,560Wildflower-rich
habitats support beneficial insects and other wildlife. We have a Bring Back the
Pollinators campaign, and we have a pledge form. The form just mentions all the
basic things that people can do– plant habitat, avoid
pesticide use, and then help spread the word. They can do that online by
going to our website. Remember to plant flowers as
native as possible and reduce pesticide use. Thank you all. Sorry to run out of time here,
but if you are interested in asking some questions,
we’ll be here for another 10 or 15 minutes. And thank you, Holli
and Sudie, so much. A couple of questions did
come in, so you ready? OK. There was a question about
herbicides, and if you know if there are any known herbicides
that are detrimental to pollinators or beneficial
insects? Can you hear me OK? I’m not using the headset. I’m using the speakerphone
now. You’re a little far away. OK, I’ll use the headset. In terms of herbicides,
we don’t know that much about toxicity. Hello? You there? Can you hear me? Yes. OK. Mainly you just want to follow
the same principles. If you are going to use
herbicide, try to mow areas so there aren’t things in flower
when you’re spraying. We do know that a number of
fungicides are toxic to insects, and so you really want
to try to avoid spraying fungicides when insects are
around, as well, or when things are in flower. There was another question about
the chemical used to treat for mosquitoes. Yeah. So we have a terrific
publication online. If you go to our main website
and you just search for mosquito management, we
have some guidelines. But it really varies with
what is being used. If they’re using
Bt there’s a– well, actually, I’m not sure. I’m getting mixed up with
gypsy moth spraying. So I’m just going to refer
you to our website. It’s a terrific guide. Another question about when
you’re establishing or permitting these pollinator
habitat areas, are native grasses beneficial to include
in those mixes? What was the question? The question was whether or not
to include native grasses when you’re establishing
wildflowers or protecting habitat. Most of the NRCS pollinator
plantings include grasses. In the past, a lot of the
grassland plantings would include forbs. It was about a 60% grasses
to 40% forbs mix. We would reverse that, or having
just 1/3 grasses would probably be enough. We recommend using the smaller
stature grasses like little blue stem, or things like that,
that aren’t going to shade out the perennials as
they’re getting established. But yeah, you definitely want to
include some native grasses in the mix. Over time, you might need to
disk that to thin out the area if you want to encourage nesting
habitats for birds. In some of our publications, we
include the fact that the native grasses are also host
plants for some of the butterflies, and that
they provide some structure, some cover. So another question is
about artificial nest structures, bee boxes. Is there a recommendation of how
many to install per acre? In general, unless you’re
planning to actively manage bee boxes, we don’t
really encourage the use of bee boxes. If you want to have them because
it’s fun to watch the bees or it’s at an educational
center and you want to use it to help teach children,
that’s fine. But what happens if you have a
lot of concentration of nest boxes, unless you’re managing
them well and carefully, then that might become a sink. You might actually be causing
problems for the bees, because diseases and pests will locate
them over time and devastate those populations. If you do want to add nesting
areas, besides planting plants with pithy stems or managing
some open ground for ground nesting bees, you can make small
bundles of bee nests using some native bamboo
or things that will disintegrate over time. Those don’t really have
to be managed. They’ll naturally decay, and
you just put up new bundles periodically. We do have a lot of specific
information on nesting if you are interested in that on our
website, and I do include some links to that in the
PDF, as well. Here’s a question about some
of the states where there’s really large row crop farms. And the question was whether
populations are better or worse in those areas, and if
there are any population maps. I am not that familiar with the
research that has looked at the impacts on that. I know there is some
new work on that. But in general, it’s
a question– He’s talking about mostly in
these row crops that are more wind pollinated. The question is all the
herbicides that are used, is there– Right. Yeah, because for instance, bees
will collect pollen from corn, and if it’s toxic. We don’t have good data on
that, as far as I know. But that’s a good question. So maybe if that person can
write to me, I’ll try to find some more details and
let you know. Do you mind contacting me? There’s a couple of quick
questions you might be able to answer quickly. There’s one about the medication
used by beekeepers to control varroa mites. Does it reduce the immunity
that a honey bee has? Do you know, Nancy? I know you’re talking more
about native bees. Yeah, the medication for varroa
mites is tough on bees. It can reduce the fecundity of
queens, and it needs to be used really judiciously
and cautiously. One more quick question was
about that specific canola study, and the question was
whether that was an organic or conventional farm? That’s a good question, and
I don’t know the answer. But I can look up the study
and let you know. So if you can write to
me, that would be good, so I who is asking. I guess maybe we’ll
have a record of who sent the questions? Yes. I think so. So I can follow up with
those two questions. And I think you pretty much
answered most of the questions that were sent in, either
through a direct question or through your presentation, and
I think it’s 10 after. Well, I’ll chime in. Thank you very much, Nancy, for
the great presentation. And I always just personally
enjoy your presentation and those that are provided
by the Xerces Society. The photos are just wonderful. No matter where they’re coming
from, they’re great photos and we appreciate your effort
in pulling your presentation together. So thank you, Nancy,
for your time. Also, thank you, Sudie, for your
time and for being our guest moderator today for the
East National Technology Support Center. I will conclude the webinar at
this time, and look forward to your participation next time. Thank you very much. Thanks.

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