Insects

Monarchs Migrate Through Georgia

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It is the time of the year when Georgians look to the sky to watch for signs of Monarch migration. These butterflies are on their way to the Sierra Madre Mountains of Mexico to overwinter on the oyamel fir trees of the area. The fir trees provide the perfect climate with a combination of optimal temperature and humidity to ensure the butterflies survive the winter. It is amazing to realize that this super-generation of migrating butterflies endure the hazards of the trip to go to a place that they have never been before.

Fall Monarch Migration Routes  Source:  USGS National Atlas

Reports around Georgia are that Monarch populations are high. A poll taken of insect enthusiasts showed that 83% have seen Monarchs heading south this year. Thirty percent of the respondents indicated that they are seeing a higher number of Monarchs than last year. This is terrific news as Monarch population numbers have been inconsistent over the last several seasons.

To increase the chances of seeing this phenomenon and to assist the butterflies create a fall migration garden. Monarchs will descend from their high migration path looking for food resources. Research shows that migrating butterflies respond to tall flowers that are easily accessible. Joe Pye weed (Eutrochium purpureum), goldenrod (Solidago spp.) and Mexican sunflower (Tithonia rotundifolia) are all proven Monarch attractors in the fall. Several of our fall-blooming native aster plants (Aster spp.) are perfect for these butterflies as well. The butterflies do not need milkweed (Ascelpias spp.), their larval host plant, at this time of the year. But be sure to include milkweed in your summer butterfly garden.

To follow the Monarch migration and to report your butterfly populations visit Journey North (https://journeynorth.org/monarchs). This organization has tabulated the reports of citizen scientists for many years and is a great resource for school groups. Monarch Watch (https://www.monarchwatch.org) provides online information for learning about these insects and their habitat needs. Contact your local UGA Cooperative Extension agent for more information about butterfly gardening and habitat building. If you miss seeing the fall migration spend time getting your garden ready for the Monarch return in the spring!

Happy Butterfly Watching!

Aphids are Pests in the Georgia School or Community Garden

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Aphids are Pests in the Georgia School or Community Garden
Jim Occi, BugPics, Bugwood.org

Do you have aphids in your garden?  If so, are they a problem?  Spring when many plants have succulent, new growth is prime aphid time.

Aphids, also called plant lice, are soft-bodied, pear shaped insects with tail-like appendages known as cornicles.  Most aphids are about 1/10th inch long and can be several colors:  green, black, pink, brown. If you have trouble identifying your pest, contact your local UGA Extension agent.

Aphids use “piercing-sucking” mouthparts to suck the juices out of tender plant parts, secreting a sticky substance known as honeydew.  Ants are attracted to honeydew and will often protect the aphids making it.  Black sooty mold grows well on honeydew and is difficult to remove from

Aphids are Pests in the Georgia School or Community Garden
Sooty mold caused by aphids. Joesph O’Brien, USDA Forest Service, Bugwood.org

the leaves.  This sooty mold makes photosynthesis almost impossible on the leaves affected.  All this means that aphids can be a problem to the community gardener.

Aphids are a danger to plants in three ways.

They can:

  1. weaken a plant making it susceptible to a secondary infection
  2. cause curling of leaves and damage to terminal buds
  3. carry and spread plant viruses

Right now our gardens are full of leafy, new plant growth and as the temperatures warm up, check the underside of

Aphids are Pests in the Georgia School or Community Garden
Aphids on lettuce

leaves and terminal buds for aphid pests.   Look for those tail-like appendages.  (Some people call them tailpipes!) Also pay attention to ant trails.  They may lead you to the honeydew making aphids.

Since aphids tend to congregate as a group, you can try removing the one or two leaves where you find them.  Sometimes a good spray with the hose is enough to remove the insects.   If not, insecticidal soap is a good choice. Sometimes I can just wipe them off with a wet paper towel.

Beneficial insects are nature’s way of controlling aphids.   So avoid applying any chemical insecticide that could harm those beneficials.  Some of the natural predators include lacewings or lady beetles (lady bugs).  You can actually purchase lady beetles from insect distributors but once you get them you can’t control where they fly.

Wishing you an aphid-free spring!

Happy Gardening!

Insect Scouting is an Important Part of Vegetable Growing

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Whether you work a large family farm, a home vegetable garden, or a 4’X8’ community garden vegetable plot, routine scouting for insects should be an important part of your vegetable growing plan. Insect pests can be a costly problem on vegetables and the lifecycles of some of our insect pests are so short that missing a week of scouting can lead to damaged crops and increased pest numbers.

Scouting involves carefully and deliberately walking though the garden looking for insects on a routine basis. Inspect the leaves and fruits/vegetables. Look on the undersides of leaves and on the stem. Evidence of boring insects can be seen on the plant stem while insect eggs are often deposited on the leaf undersides. If you are unsure of an insect identification, contact your local UGA Cooperative Extension agent for assistance. Do not automatically reach for an insecticide!

Insect eggs are easily removed. Simply remove the entire leaf and fold the leaf over on itself and smash the eggs. Or, if you want to preserve the leaf, use sticky tape to remove the eggs. Place tape on top of the egg mass and gently pull removing the eggs. Fold the tape on itself and smash the eggs.

Squash bug eggs are easy to remove.

Eggs like these are easy to miss if you don’t routinely scout your garden! Dealing with squash bug eggs is easier than managing the 30+ pest insects that could mature from these eggs. A helpful video goes through the easy steps.

Learning about the insects that are common pests for the food crops you are growing can be very helpful. Leaf-footed bugs (Leptoglossus spp.) are a problem for tomatoes while squash bugs are pests in cucumbers, squash and pumpkins. Aphids (Aphidoidea superfamily) are a common problem especially when plants are full of liquid, after a rain, or when plants are growing quickly. Mexican bean beetles (Epilachna varivestis) can easily destroy a bean crop but these insects have been mistaken for beneficial lady beetles.

Pest Mexican bean beetles can be mistaken for beneficial lady beetles.

It is estimated that only 3% of insects are pests so the insects you find in your garden are not always problematic. Don’t assume every insect you find is a “bad bug!” Take time to learn about beneficial insects such as assassin bugs, parasitic wasps, and lady beetles. These can be tremendous allies in your garden. Often these insects need floral resources and the plants you have added to attract pollinators will also help other beneficial insects.

The copper colored ovals in the photo below are aphid mummies. A helpful parasitic wasp laid an egg inside an aphid pest (green insect below). As the egg hatched the resulting larva consumed the aphid insides for nutrition. When the wasp matured it emerged from the aphid leaving the empty shell, aphid mummy, behind. Adult wasps will be looking for some nectar so your pollinator garden will be useful here.

Aphid mummies mean that parasitic wasps are working for you.

Scouting is just one tool of an integrated pest management (IPM) program. Other tools include:

¥ Altering planting time to miss large insect populations
¥ Using trap crops
¥ Starting with healthy soil
¥ Keeping the garden clean of debris
¥ Hand-pulling weeds
¥ Creating habitat for beneficial insects and pollinators
¥ Watering wisely
¥ Using plants that are proven to do well in your area

Happy Gardening!

Tomato Hornworms and Parasitic Wasps

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Tomato hornworms (Manduca quinquemaculata) are a serious problem for tomato growers. These caterpillars have a large appetite and can quickly defoliate a tomato plant. If you find hornworms in your tomatoes, simply pick them off and drop them in soapy water. However, if you find a hornworm with white oblong obtrusions, leave it!

The white obtrusions are actually the cocoons of a parasitic wasp. A female wasp has laid her eggs under the skin of that hornworm. As the eggs hatch the larvae actually feed on the hornworm insides. The larvae eat their way out of the caterpillar and spin the cocoons you see. Eventually adult wasps will emerge from the cocoons and the weakened hornworm will die.

Photo credit: Texas A&M

The hope is that the emerging wasps will find other tomato hornworms to parasitize and you will have managed that pest. There are some generalist parasitic wasps that will provide that service for you. There is a braconid wasp, Cotesia congregates, that specifically looks for tomato hornworms. This small wasp has clear wings and as an adult they are nectar feeders. To persuade the wasps to stay in your garden you will need to have flowers. The small braconid wasps are attracted to small flowers like yarrow and small asters.

Instead of reaching for an insecticide for tomato hornworms encourage the ecosystem to assist you in managing that pest!

Happy Gardening!

They’re Back! Japanese Beetles in Your Garden

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Did you know that Japanese Beetles (Popillia japonica) feed on over 300 plant species?  Plants in the rose or cherry families seem to be a favorite targets.   The first one in my North Georgia garden appeared on June 1st.

Japanese beetle damage

In the past gardeners reached for an insecticide to handle the problem.  Sevin spray, Carbaryl (1-naphthyl N-methylcarbamate), was a popular choice.  However, Sevin is a broad spectrum insectide that kills other beneficial insects!  Sevin kills over 100 different insect species, including bees.

If you want to attract the beetles to your garden, add a pheromone trap.  You will attract them from all over your area.  Seriously, they will bring more beetles to your garden.  Maybe you can talk a neighbor into purchasing one!

There is an easier way to handle a Japanese Beetle infestation.

Fighting Back!

A jar of soapy water is your best weapon against Japanese Beetles.

To control the beetles simply pick them off of your plants and drop them in a jar of soapy water.  Be aware that they will fly away so act quickly.  So practice your technique of grabbing or forcefully knocking the insects into the jar.  They will drown quickly.

When I was younger my family planted a fruit orchard.  When the orchard was young one of my jobs was to pick off Japanese Beetles and deposit them into a jar of gasoline I carried around the orchard.  Wow, the gasoline was not needed.  Soapy water works just as well.

Worst case scenario, hang in there.  They won’t be around for long!

Happy Gardening!

Pollinator Week 2017

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It is Pollinator Week 2017!  Since last year the rusty patched bumble bee has been put on the Endangered Species List and honey bee keepers in the United States reported hive losses of 33% over 2016-17.  How can the average Georgia gardener help our pollinators?  These steps are easy and will make a real difference to our pollinating insects:

Read Georgia’s Pollinator Protection Plan

University of Georgia entomologists collaborated with stakeholders across the state to develop Protecting Georgia’s Pollinators.  There is a role for every Georgia citizen whether you are a farmer, a landscaper, or a homeowner.

Plant Flowering Plants

Adding flowering plants to your food garden attracts pollinators and as a bonus can also attract other beneficial insects.  To attract butterflies, adding plants that sustain the caterpillar stage of the butterfly is important.   The University of Georgia has done research on pollinator plants and has suggestions for plants that do well in our climate.

There are many pollinator plants that thrive in our Georgia climate.

Plan for a Succession of Bloom

Strive to have plants flowering as much of the year as possible.  Even during the winter months if temperatures rise above 50 F, bumble bees and honey bees are flying and looking for nectar and pollen.

Winter Honeysuckle (Lonicera fragrantissima) is not a true honeysuckle and blooms in the winter months.

Create a Water Source

Adding pebbles or stones to your birdbath makes a wonderful water source for small insects with  delicate legs.  By cleaning the birdbath once a week you will avoid any mosquito problems.  If you don’t have a birdbath the drainage pans used to catch the water running out of potted plants can be used.

Wisely Use Any Pesticide

Examine your use of any pesticide.  Is the pesticide really necessary?  Your UGA Extension agent can assist you with any pest situation and guide you in deciding if a pesticide is the best answer.  Make sure you thoroughly read and follow any pesticide label.  The label is the law.

Have Your Garden Certified as a Georgia Pollinator Space

The Georgia Pollinator Spaces program is an initiative designed to recognize gardeners that consciously make an effort to improve pollinator health by creating pollinator habitat.   To get inspiration take a look at some of the gardens that are part of the program.

However you decide to celebrate Pollinator Week be sure to check our daily pollinator posts on the UGA Community and School Garden Facebook page.

Happy Pollinator Week!

 

 

Insect Scouting Hints

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Insect scouting is an important part of integrated pest management, whether you are a large scale farmer or just “farm” a 4′ X 8′ raised bed.   Here are some hints to help you scout successfully so that you can manage garden insect pests:

Hint #1  Look under plant leaves

Damaging insects often stay on the underside of leaves or in leaf crevices and plant whorls.  Check those areas carefully.

Hint #2  Look for insect eggs

Insect eggs are small and by spotting and removing them you limit future damage.  Squash bug eggs are a good example.

Hint #3  Confirm insect identification

The majority of insects are not harmful to your plants.  Many are actually beneficial and can help you manage pests.   If you are unsure of an insect identification contact your local UGA Cooperative Extension office for confirmation.  Oftentimes you can send your agent a photo and that is all he/she needs to assist you.

This lady beetle larva looks menacing but is really helpful in the garden. Photo: bugguide.net

Hint #4  Scout at night

Some insects do their damage at night.  Grabbing a flashlight and scouting after dark could yield some interesting results.

Happy Scouting!

Blueberry Pollination in Your Community or School Garden

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With the recent cold damage to the commercial blueberry crop in South Georgia, the blueberries in our community, school, or home gardens are all the more precious this year.   As a result, it seems like gardeners are paying more attention to their blueberry flowers.  I have gotten several emails asking about slits appearing in the sides of blueberry flowers.  This is not unusual and it probably happens every year, gardeners just don’t notice it.

The slits are made by carpenter bees who are “robbing” the flower.  They chew slits in the sides of the flowers and get the nectar without having to go into the flower.  A result of robbing is that the bees don’t leave or pick up any pollen.   Pretty sly bees, right?  Research shows that this action still results in some pollination, it is just not ideal.   Other bees may use these slits as well to retrieve whatever nectar is left.

Blueberry Pollen is Heavy

Blueberry pollen is heavy and sticky.  It does not move around easily and isn’t wind blown.  The blueberry flower shape does not lend itself to adequate self-pollination so pollinators are needed even with the self-pollinating types of blueberry plants.

Blueberry Pollination in Your Community or School Garden
Southeastern Blueberry Bee. Photo by Hannah Barrack of NC State.

Bee Pollination

Several native bee species pollinate blueberries including the Southeastern blueberry bee.  This bee also pollinates several flower types that bloom at the same time.  The male Southeastern blueberry bee has a yellow face.

The smaller native bees are shown to be superior pollinators in these plants.  You will also see bumble bees in the blueberry patch.  They vibrate their flight muscles inside the flower aiding in pollen exchange, flower sonication.  Also, honey bees are often brought into blueberries fields to aid in pollination.  To learn more about bees in the blueberry patch visit North Carolina State’s Blueberry Pollinators .

Blueberry Pollination in Your Community or School Garden
Honey bees on the fly! Photo by Joe Thompson.

I enjoy pulling up a chair near my blueberry plants to watch the pollinators at work.  Try it and you will be amazed at the different insects you see.

If you don’t have blueberries in your community or school garden, why not?  They are a fantastic addition to the garden.  Being perennial shrubs they add a nice permanent shape to the space.  School gardeners should look at later season varieties.

Happy Gardening and I wish you all a very large blueberry harvest this year!

Don’t Leave a Weedy Mess!

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Many community gardeners don’t take advantage of our Georgia winters and finish their garden as the temperatures get cool.  As you get ready for the garden break, don’t leave a weedy mess!

A garden plot left full of weeds is not just an eyesore that is unfair to your fellow community gardeners, it can be detrimental to your future crops.

The Weed Seed Bank – don’t make deposits

Weed scientists have a saying:

One year’s seeding means ten years weeding!

If a weed is allowed to produce seed those seeds will happily deposit in your plot to germinate at another time.  In weed science terms, you have added to the dreaded weed seed bank.   Plant seeds are tough and are a plant’s mechanism for long-term survival.

Some seeds from a legume collected beneath permafrost in the Yukon germinated.  The estimated age of those seeds?  10,000 years old!

A sample of seeds dated 237 years old from a British museum herbarium germinated.

Garden Debris Can Create a Welcome Over-Wintering Spot for Pests

Pests like Mexican bean beetles can overwinter in garden debris waiting for your spring planting of bush beans.  Don’t give them that extra edge.

What are some alternatives?  If you aren’t growing cool-season vegetables, try growing a cover crop.  Or, cover your plot with plastic and do some winter solarization.  At the very least, clean your plot and add a cover of mulch.

Give next year’s warm-season crops a good start while being a good community garden neighbor.

Happy Gardening!

 

 

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