by Pat Williams | Sep 9, 2021
As homeowners, we do value our trees and no one wants to lose a shade tree especially on the house’s south side in Florida. On a recent site visit, a hickory tree had multiple concerns. Upon closer inspection, the tree had a bacterial infection about 30” off the ground with a smelly, black-brown ooze seeping forth. The leaf canopy was riddled with beetle holes and leaf margins were chewed by caterpillars. When leaves were viewed under the microscope, thrips (insects) and spider mites were found running around. The biggest homeowner cosmetic concern arose from hickory anthracnose (fungus) and upon closer inspection found the leaves to have hickory midge fly galls. The obvious question is should the tree come down? I’ll have you read the whole article before giving you the answer.
Each hickory gall is approximately 3/16″ wide.
Hickory anthracnose or leaf spot as seen in the banner photo is caused by a fungal infection during the wet summer months in Florida. The homeowner can usually recognize the disease by the large reddish brown spots on the upper leaf surface (sending a sample to the NFREC Plant Pathology Lab will confirm the diagnosis) and brownish spots with no formal shape on the bottom. Be sure to rake and remove all leaves to prevent your disease from overwintering close to the tree thus reducing infection next year.
A hickory gall has been cut in half to show the leaf tissue.
The fungus can be lessened by good cultural practices and appropriate fungicidal applications. Please remember it is best left to professionals when spraying a large tree. This alone is not cause to remove your tree.
Hickory gall is caused by the hickory midge fly, an insect that lays eggs in the leaf tissue. The plant responds by building up tissue around each egg almost like the oyster when forming a pearl.
As the gall tissue grows, eggs hatch and larva start to feed on this tissue. The larva will continue to
The larva has eaten all soft material inside the gall and is ready to pupate.
feed until it is ready to pupate within the gall. After forming a pupa, the midge fly will eventually emerge as an adult and females will continue to lay eggs on other leaves. The galls are more of a cosmetic damage and because your hickory leaves will fall from the tree as winter comes, the galls will normally not cause enough damage to worry about each year. Once again good cultural practices and disposal of each year’s leaves will reduce the gall numbers next year.
In a large tree with many leaves, foliar feeding by beetles and caterpillars do cause damage though the leaves will still produce enough food (photosynthesis) to keep the tree alive. Most of us never climb our trees to look at leaves to see the small insects/mites and there are more than enough leaves to maintain tree health.
The biggest concern during my site visit was their tree’s bacterial infection. A knife blade was pushed into the wound area and went in less than 1/4″. The homeowner was instructed to look at bactericide applications. In the end, this hickory tree with so many problems is still shading the home and helping cool the house. It is still giving refuge to wildlife and beneficial insects. When in doubt give our trees the benefit and keep them in place. Remember your local Extension agent is set up to make site visits and saving a tree is time well spent.
by Larry Williams | Aug 26, 2021
Hot, summer months are not the time to be using most lawn herbicides.
One issue is the heat of summer. Most lawn herbicide labels include statements such as the following.
“Do not apply when temperature exceeds 90°F.” “Do not broadcast apply this product when air temperatures are above 90°F (85°F for St. Augustinegrass) unless temporary turf injury can be tolerated.”
Every year we’ll see lawns that are injured or killed because of lawn herbicides being applied when temperatures are too hot.
Summer is usually a rainy and windy time of the year. Many lawn herbicide labels include statements such as the following.
“Allow 12 hours after application before watering lawn for maximum effectives on listed weeds.” “Apply only when wind is no more than 10 mph.” “Applying this product in calm weather when rain is not predicted for the next 24 hours will help to ensure that wind or rain does not blow or wash pesticide off the treatment area.”
It is critical to read and follow the label directions and precautions for any pesticide you use. Pesticide labels, including herbicides, include the following statements.
“To the extent consistent with applicable law, the buyer assumes all risks of use, storage, or handling of this product not in accordance with label directions.” “It is a violation of Federal law to use this product in a manner inconsistent with its labeling.”
Crabgrass growing in centipedegrass lawn. Photo credit: UF/IFAS Extension
By the time summer arrives, many of the lawn weeds are mature, which means they are well established with extensive root systems. These mature, well established weeds are much more difficult to control. They are more susceptible to herbicides when they are small, young, and not well established. Also, these mature weeds have been allowed to produce countless numbers of seeds as they move into summer. Most weeds are prolific seed producers. For example, a single crabgrass plant (a common summer lawn weed) can produce 150,000 seeds.
Applying a preemergence lawn herbicide in February to help prevent summer annual weeds such as crabgrass or applying a postemergence lawn herbicide during spring while the weather is mild and before the weeds are out of control simply makes more sense than waiting until summer.
The best options now with lawn weed control involve continuing to follow good mowing practices, maybe hand removal of some weeds, and just simply waiting it out until next February and spring to worry with the use of lawn herbicides.
In the meantime, you may want to read the following UF/IFAS Extension publication on lawn weed control.
https://edis.ifas.ufl.edu/pdf/EP/EP14100.pdf
Larry Williams, UF/IFAS
by Daniel J. Leonard | Aug 26, 2021
Nearly everyone likes turfgrass lawns. They’re pretty and green. They filter water, chemicals, and nutrients before they enter our groundwater systems. They provide a recreation spot for people and pets. But lawns also come with maintenance tasks, one of which is weed control. Fortunately, keeping our common Centipedegrass lawns relatively weed free is as simple as smart management and utilizing herbicides effectively. Though the number of herbicides available for purchase can be overwhelming, you only need three to keep weeds at bay – a selective grass herbicide, a strong broadleaf herbicide, and a sedge herbicide!
Dollarweed, one of the toughest broadleaf weeds for homeowners to control. Picture courtesy of Julie McConnell, UF/IFAS.
First up on the essential herbicide list is the selective grass herbicide Sethoxydim. While most folks’ weed focus is centered on broadleaf weeds, grassy weeds like Crabgrass, Bahiagrass, Goosegrass, and others can be just as problematic and make for a very unsightly lawn. Enter Sethoxydim. Cheap and easy to find, Sethoxydim is offered as the active ingredient in many branded products like Fertilome Over the Top Grass Killer, Hi-Yield Grass Killer, and many more. These products control weedy grass species without seriously harming Centipedegrass or broadleaf ornamental trees and shrubs (Centipedegrass may temporarily be yellowed after sethoxydim application but will recover). Not only will it kill out the unwanted grass growing in your Centipede, but it will also remove these weeds from your flower beds!
Second, having a strong broadleaf herbicide on hand is necessary. I say “strong” because many of the homeowner grade products available at garden centers simply don’t have the “juice” to control tough broadleaf weeds like Dollarweed, Doveweed, Virginia Buttonweed, and others. For this job, I prefer to use a commercial grade 3-way product like Celsius WG by Bayer. Celsius WG is a 3-way combination herbicide with a healthy dose of Dicamba as its primary ingredient. Though Dicamba is a notoriously volatile chemical known to cause damage to unintended plants through drift in hot weather, combining it with the two other products in Celsius WG makes it safe to use in lawns, even in the heat of summer. While strong broadleaf herbicides like Celsius WG are expensive on the front end, don’t let that deter you. These products wind up being very cost effective in the long run due to minute mixing rates (one bottle goes a very long way in most residential lawns) and effectiveness – you simply will not need to waste time and money spraying lawn weeds over and over to obtain control like is necessary with lesser products – one or two applications will solve the toughest broadleaf weed problems.
Finally, any good lawn weed control program will include a quality sedge control herbicide. Sedges (often called “nutgrass”) look like grasses but are a completely different category of plants and as such, require specialized herbicide chemistries to achieve control. Sedge weeds prefer wetter areas of lawns, though they can occur in pretty much any lawn site and are very unsightly. For this weed category, there are several options available to homeowners. The one that consistently provides the best control in lawns is Halosulfuron-methyl, the active ingredient in the aptly named product Sedgehammer. Conveniently coming in individually pre-mixed packets for small lawns or a larger bottle when more acreage is to be treated, Sedgehammer couldn’t be easier to mix and use. While Sedgehammer and similar products are extremely effective in controlling various sedge weeds, they tend to work very slowly, and patience is required. Weeds immediately stop growing following a Sedgehammer application, but it can take up to three weeks to notice the sedges dying.
While having and using the above three herbicides can control almost any weed homeowners may encounter in their lawns, it is important to remember that herbicides are not substitutes for proper lawn management. When good cultural practices in lawns are followed, such as mowing at the correct height, only watering when necessary, following UF/IFAS fertilizer recommendations, etc., chemical weed control may not even be necessary in many cases! Also, once the decision to purchase and use chemical herbicides has been made, it is critical that one always read the label before using any herbicide product. This ensures safe and effective use of the product; the label is literally the law!
For assistance in choosing the correct herbicide for your lawn and other lawn care concerns, contact your local UF/IFAS Extension Office! Happy Gardening!
by Beth Bolles | Aug 18, 2021
In a garden with a variety of flowers, pollinators will be abundant. Sometimes we don’t always recognize the specific pollinator when we see it, but there are some native pollinators that leave other signs of their activity. One of our medium-sized native bees will leave a distinctive calling card of recent activity in our landscape.
Leafcutter bees have collected circular notches from the edges of a redbud tree. Photo by Beth Bolles, UF IFAS Extension Escambia County.
If you see some of the leaves of trees and shrubs with distinct circular notches on the edges of the leaves, you can be sure the Leafcutter bee is present. The females collect the leaf pieces to make a small, cigar-shaped nest that may be found in natural cavities, such as rooting wood, soil, or in plant stems. Each nest will have several sections in which the female places a ball of pollen and an egg. The emerging larvae then have a plentiful food source in order to develop into an adult bee.
When identifying a leafcutter bee in your landscape, look for a more robust bee with dark and light stripes on the abdomen. These bees also have a hairy underside to their abdomen where they carry the pollen. When loaded with pollen their underside will look yellow.
Leafcutter bees are solitary bees that are not considered aggressive. A sting would only be likely if the bee is handled. Your landscape will have many plants that a leafcutter may use for nesting material. The pollinating benefits of these bees far outweigh any cosmetic injury to the plant leaf margins.
Visit Featured Creatures to see a photo of the leaf pieces made into a nest.
by Mary Salinas | Aug 18, 2021
For those of you who tuned into the July 29 edition of Gardening in the Panhandle LIVE, beneficial insects was the topic of the day. Here are links to the publications our panelists talked about.
Mantid. Photo credit: David Cappaert, Bugwood.org.
How do I identify the kind of insect I have?
Recognizing beneficial bugs: Natural Enemies Gallery from UC Davis http://ipm.ucanr.edu/natural-enemies/
How to distinguish the predatory stink bug from the ones that harm our crops: https://entomology.ces.ncsu.edu/wp-content/uploads/2014/01/FL-pred.jpg
How to tell difference in stink bugs and leaf footed insects. Are both harmful? UF/IFAS Featured Creatures: leaffooted bug – Leptoglossus phyllopus (Linnaeus) (ufl.edu)
How can I tell bad beetles from good ones? Helpful, Harmful, Harmless Identification Guide is one resource available: http://ifasbooks.ifas.ufl.edu/p-153-helpful-harmful-harmless.aspx
How can we encourage beneficial insects?
How can we encourage the beneficial insect species?
- Plant more flowers attract pollinators that also feed on insects.
- Diversity of plants in the landscape.
- Use softer or more selective pesticides to minimize damage to beneficials.
Is it helpful to order beneficial insects such as lady bugs? Encouraging Beneficial Insects in Your Garden OSU: https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw550.pdf
How effective is buying predatory insects to release in your greenhouse? Natural Enemies and Biological Control: https://edis.ifas.ufl.edu/publication/IN120
Can I buy beneficial insects to start breeding in my garden? Natural Enemy Releases for Biological Control of Crop Pests: https://www2.ipm.ucanr.edu/agriculture/natural-enemy-releases-for-biological-control-of-crop-pests/
What benefit would result by planting city right-of-ways with native wild flowers? https://edis.ifas.ufl.edu/publication/in1316; https://adamgdale.files.wordpress.com/2020/03/gcm_feb2020.pdf
Can an individual gardener sustain an ecosystem for beneficial insects? Penn State Article on beneficial insects that mentions some flowering plants that help support predators and parasitoids: https://extension.psu.edu/attracting-beneficial-insects
Specific Insects
How do I get rid of mole crickets? UF/IFAS Mole Crickets: https://edis.ifas.ufl.edu/entity/topic/mole_crickets
Are wasps really beneficial? Beneficial Insects: Predators!: https://sfyl.ifas.ufl.edu/sarasota/gardening-and-landscaping/horticulture-commercial/integrated-pest-management/beneficial-insects/
Is a dish soap solution effective against wasps? Soaps, Detergents, and Pest Management: https://gardeningsolutions.ifas.ufl.edu/care/pests-and-diseases/pests/management/soaps-detergents-and-pest-management.html
How to control leaf footed bugs? Handpick them, attract beneficials, create diverse plantings in landscape, accept some damage, and control them when in the juvenile stage.
Can you tell me about praying mantids? Praying Mantids: https://entomology.ca.uky.edu/files/efpdf2/ef418.pdf
Are there any beneficial insects that keep mosquito populations down? Dragonfly larvae in water, mosquitofish
What are the little insects that hop out of centipede grass? Are they beneficial?
Spittlebugs and your lawn: https://nwdistrict.ifas.ufl.edu/hort/2020/05/27/spittlebugs-and-your-lawn/
How to stop Eastern Black Swallowtail Butterflies laying eggs on parsley – the hatched caterpillars eat it all. Plant extra or put a screen over plant.
Extra fun video!
Take a look at this video of parasitic wasp attacking aphids: Parasitic Wasps | National Geographic – YouTube
by Danielle S. Williams | Aug 11, 2021
Integrated Pest Management or ‘IPM’ is a sustainable approach to managing plant pests by using several different methods to cause the least harm to people, property, and the environment. IPM focuses on the management of problems rather than their eradication. Using IPM strategies in your garden is one way to ensure its productivity!
Avoiding Pest Problems
Prevention is key to IPM! It is important to select the right plant, for the right place at the right time. It’s also important to select pest-resistant plant varieties and maintain healthy plants through proper watering and fertilization.
- Plan before you plant. Be sure not to plant in a location not suited for a particular plant. Stressed plants are more susceptible to insects and disease.
- Start with healthy plants. Do not plant plants with insects or disease.
- Monitor the lawn and garden regularly. You’ll want to be able to detect a pest problem earlier rather than later.
- Water and fertilize properly. Too much of either can make plants vulnerable to insects and disease.
- Encourage beneficial insects in your garden. Learn to recognize the insects in your garden and let the good ones do the work for you!
Recognizing Pest Problems
Depending upon the insect and the life cycle stage they are in, they may look different than we are used to! Here is a photo of the pupal stage of a lady beetle.
Scouting or monitoring the garden or plants in the yard frequently helps detect problems early. Some of the common insects you’ll find in your garden are: aphids, mealybugs, scales, whiteflies, thrips, mites, caterpillars, and stinkbugs. Often times you’ll find damage from the insect before you see the insect itself. Chewed or deformed leaves, sooty mold or a colony of ants scurrying up and down stems are all signs an insect may be present.
Treating Pest Problems
IPM is the best strategy for dealing with pests in the lawn and garden. IPM strategies:
- Remove affected plant leaves or parts. If an insect or disease is heavily concentrated in an area, you can reduce or eliminate the problem by simply removing it.
- Pick insects off by hand. Be sure to dispose of them so they don’t make it back into the garden.
- Look for beneficial insects. If you see a pest outbreak, try to determine if it is being managed by natural enemies. Many insects such as ladybugs and lacewings prey on pest insects and removing them will just help the pest insects. If you need help identifying insects, contact your local county Extension agent!
- Try the above strategies before pesticide use. If the problem persists and pesticides are needed, use products that have a reduced-risk to the environment such as insecticidal soaps, horticultural oils, botanicals, or microbials.
- Read and follow all pesticide label instructions. The label is the law!
For more information on integrated pest management, please visit:
