A natural disaster such as Hurricane Michael can cause excess standing water which leads nuisance mosquito populations to greatly increase. Floodwater mosquitoes lay their eggs in the moist soil. Amazingly, the eggs survive even when the soil dries out. When the eggs in soil once again have consistent moisture, they hatch! One female mosquito may lay up to 200 eggs per batch . Standing water should be reduced as mush as possible to prevent mosquitoes from developing.
You should protect yourself by using an insect repellant (following all label instructions) with any of these active ingredients or using one of the other strategies:
- Oil of lemon eucalyptus
- Para-menthane diol
- An alternative is to wear long-sleeved shirts and pants – although that’s tough in our hot weather
- Wear clothing that is pre-treated with permethrin or apply a permethrin product to your clothes, but not your skin!
- Avoid getting bitten while you sleep by choosing a place with air conditioning or screens on windows and doors or sleep under a mosquito bed net.
Now let’s talk about mosquito control in your own landscape.
Let’s first explore what kind of environment in your landscape and around your home is friendly to the proliferation of mosquitoes. Adult mosquitoes lay their eggs on or very near water that is still or stagnant. That is because the larvae live in the water but have to come to the surface regularly to breeze. The small delicate larvae need the water surface to be still in order to surface and breathe. Water that is continually moving or flowing inhibits mosquito populations.
Look around your home and landscape for these possible sites of still water that can be excellent mosquito breeding grounds:
- bird baths
- potted plant saucers
- pet dishes
- old tires
- roof gutters
- tarps over boats or recreational vehicles
- rain barrels (screen mesh over the opening will prevent females from laying their eggs)
- bromeliads (they hold water in their central cup or leaf axils)
- any other structure that will hold even a small amount of water (I even had them on a heating mat in a greenhouse that had very shallow puddles of water!)
You may want to rid yourself of some of these sources of standing water or empty them every three to four days. What if you have bromeliads, a pond or some other standing water and you want to keep them and yet control mosquitoes? There is an environmentally responsible solution. Some bacteria, Bacillus thuringiensis ssp. israelensis or Bacillus sphaericus, only infects mosquitoes and other close relatives like gnats and blackflies and is harmless to all other organisms. Look for products on the market that contain this bacteria.
For more information:
UF/IFAS Mosquito Information Website
This tomato hornworm is being parasitized by beneficial wasps. Photo credit: Henry Crenshaw
Why would anyone allow dozens of wasps to thrive in their garden? Why would they let caterpillars keep moving through their pepper bushes? Don’t they know you can spray for that?
As Extension agents, one of the tenets we “preach” in gardening is the concept of Integrated Pest Management (IPM). This technique involves a series of insect control measures that begin with the “least toxic” method of control, using chemicals as a last resort. One of those least toxic measures is “biological control”, in which a natural predator or parasite is recognized and allowed to remove a pest insect naturally. It is important to be able to recognize some of the more common garden predators and parasites. Many times these insects look strange or dangerous, and they are mistaken for pests and killed.
One such beneficial insect to the home gardener is the braconid wasp (Cotesia congregatus). Most people shudder at the mention of wasps, but these tiny (1/8 inch long), mostly transparent wasps are of no danger to humans. Quite the opposite–they are an excellent addition to gardens, especially if you are growing tomatoes or peppers. One of the major pests to these favorite vegetables is the tomato hornworm (Manduca quinquemaculata), a fat green and white-striped caterpillar.
The beneficial wasp can control hornworms because females lay eggs under the caterpillar’s skin, after which the eggs hatch and larvae feed on the hornworm. After eating through the caterpillar, they form dozens of tiny white cocoons on the caterpillar’s skin. The tomato hornworm is rendered weak and near death, and the vegetable crop is saved.
If you happen to find a tomato hornworm covered in these small oval cocoons, consider yourself lucky. Let the process continue, allowing the new generation of beneficial wasps to hatch and continue their life cycle. They will control any future hornworms in your garden, and the whole process is fascinating to watch!
For questions on integrated pest management, beneficial insects, or growing peppers and tomatoes, call your local County Extension office.
Hydrangea leaf spot disease
Photo credit: Larry Williams
It is not uncommon to see leaf spots on your hydrangeas during late summer and fall.
These spots are caused by a number of fungal diseases. Plant fungi and wet weather go hand-in-hand. Florida’s high humidity, heavy dews and frequent rains during spring and summer provide perfect conditions to allow fungal diseases to flourish. Bacterial leaf spots can be part of this foliage disease mix, too.
Common foliage diseases seen on hydrangeas this time of year include Phyllosticta leaf spot, Target leaf spot, Bacterial leaf spot, Botrytis and Cercospora leaf spot.
These foliage diseases are the norm rather than the exception as we move into the wet summer months and on into fall. As a matter of fact, you would be hard-pressed to find any hydrangea in our area without some evidence of infection now.
This late in the year it is more of a “grin and bear it” problem. In other words, it’s too late to do much about the fact that your hydrangea plant has leaves covered in ugly spots. By now many of the infected leaves are turning brown, withering and dropping prematurely from the plant.
Cercospora leaf spot is one of the most common foliage diseases of hydrangeas. Along with most of the leaf spot diseases, it begins as small dark-colored specks on the leaves. The small specks generally go unnoticed. But as the spots continue to slowly enlarge, mostly maintaining a circular shape, they become more obvious. With heavy infection, individual spots can coalesce forming larger irregular shaped brown areas on individual leaves. The individual spots may have a purplish halo with gray center.
There are some fungicides that can help prevent these leaf spots. But you’d have to begin treatment early in spring before any leaf spots exist and spray the plant every 10 to 14 days during favorable disease development (humid, rainy weather), which is pretty much our spring and summer months. These types of diseases are prevented, not cured. That’s the “grin and bear it” part of waiting until now.
The fungus survives on infected leaves. So, the best thing to do now is to remove and dispose of infected leaves. Also, be careful to not wet the leaves when irrigating the plants during the growing season.
New leaves of spring should be spot/disease free as they emerge. But the cycle of life for these leaf spot diseases will again result in spotted/diseased leaves on your hydrangeas next summer and fall without persistent treatment.
The good news is that these leaf spot diseases normally do not cause permanent/long-term damage for hydrangeas. They just make the plant look ugly.
On June 6th, we held an Invasive Species Workshop: Air Potato Challenge and Species Awareness day at the UF/IFAS Extension Office in Panama City. Over 700 air potato leaf beetles were distributed to more than 30 sites in Northwest Florida by citizen scientists to help manage the invasive air potato vine!
We were joined by University of Florida Wildlife Ecology Professor, Dr. Steve Johnson, and representatives from Florida Fish and Wildlife Conservation Commission (FWC), and Science and Discovery Center (SDC) of Northwest Florida. If you would like to learn more about topics covered at the workshop, please click on the videos below. We hope you enjoy and share!
Steve Johnson, UF/IFAS Extension, shares Exotic Invaders: Reptiles and Amphibians of Concern in Northwest Florida. (Updated June 7 2018 – 10AM CDT) http://www.eddmaps.org and http://ufwildlife.ifas.ufl.edu/steve_johnson.shtml
Rick O’Connor, UF/IFAS Extension, tells us about the ball python, a potential invasive species. Rick also provides an overview of keeping pythons and other snakes as pets. http://edis.ifas.ufl.edu/pdffiles/UW/UW34100.pdf
Holli Nichols, FWC, tells us about the Wildlife Assistance program for homeowners and property owners. Holli helps out find solutions for negative encounters with Wildlife. Most problems are easily solved and she provides a few tips. Holli also tells us about the FWC Pet Amnesty Program for Exotic Pets. Watch to learn more. http://myfwc.com/conse…/you-conserve/assistnuisance-wildlife
Kira Burdeshaw, SCN of NW FL, shows off the tokay gecko we found at the Extension office on the front porch earlier in May. The Gecko moved in with Kira and her other reptiles at the Science and Discovery Center.
Kira Burdeshaw, SCN of NW FL, introduces us to Jewel the iguana and Eva, a boa contrictor. She also tells us more about the Science and Discovery Center in Northwest Florida. http://edis.ifas.ufl.edu/pdffiles/IN/IN52800.pdf and http://edis.ifas.ufl.edu/pdffiles/UW/UW34200.pdf
Mike Kennison, FWC, shares resources and efforts to manage lionfish in Florida waters. Learn more about this Summer’s Lionfish Challenge at http://myfwc.com/…/saltwater/recreational/lionfish/challenge
Derek Fussell with FWC Invasive Aquatic Plant Management talks about Giant Salvinia, a species of concern for Deer Point Lake in Bay County, Florida. Here’s a link to a story about the discovery of giant salvinia in Bay County from 2016 http://nwdistrict.ifas.ufl.edu/…/nisaw-2016-working…
Derek Fussell shares a behind the scene’s view of their new boat for controling aquatic plants in Bay County and Northwest Florida. We will visit with Derek and Jamie later and show some of the aquatic invasives they work to control everyday!
Scott Jackson and Julie McConnell, UF/IFAS, show Air Potato Beetles and discuss vine look-alikes. Schedule for the June 6, 2018 is briefly discussed. https://t.co/8c9KdV9Ezm More at https://t.co/gVh28N714E#airpotatochallenge #invasivespecies
European honey bee. Photo credit: UF/IFAS.
Bees, butterflies and other insects play important roles as pollinators in our environment. Over 50 major crops in the United States and at least 13 crops in Florida depend on honey bees. Many native plants in natural areas also depend on insect pollinators for reproduction. In Florida, over 300 bee species play a role in pollination!
Many factors affect the health of our pollinators. One of those factors we can easily control in our own landscapes is exposures to pesticides. How are bees and other pollinators exposed to pesticides? Here are some of the major routes:
- Drift of pesticides sprayed in breezy/windy conditions
- The erosion of contaminated topsoil blowing in the wind
- Direct feeding on pollen and nectar of treated plants
- Contact with pesticides that have blown onto plant surfaces
- Contact with water transpired by leaves of treated plants
- Pesticides that move down through the soil to affect ground dwelling bees and other insects
Did you know that bees become statically charged when they fly causing particles in the air to attract to them?
What are some ways that we can reduce the risk of exposure to pollinators in our landscapes?
- Use integrated pest management principles to reduce the incidence of pests and their impacts.
- Avoid treating areas containing flowering weeds/plants with insecticides. If you must treat your lawn with an insecticide, and it contains flowering weeds, mow the lawn and remove the flowers just before applying the insecticide.
- If you must apply a systemic insecticide to your lawn, leave a buffer strip of several feet between the lawn and the border of landscape beds with flowering plants. This will prevent the flowering plants from up taking the systemic product.
- Postpone any insecticide treatment until after all blooms have fallen from flowering ornamentals. Never apply an insecticide to blooms or flowering plants.
- Avoid the use of neonicotinoids as this class of insecticides can be more toxic to bees than other classes of insecticides. There are many effective alternatives.
Bee friendly to our pollinators!
For more information:
Minimizing Honey Bee Exposure to Pesticides
Creating and Maintaining Healthy Pollinator Habitat – Xerces Society
Take lessons from a farmer to control fire ants in your garden. Photo by Molly Jameson.
As I near the three-year mark of being an Extension Agent, I think about how fortunate I am to have a career that not only encourages me to meet all our local farmers, but also to learn from them and share their knowledge with the community.
A few months ago, I visited Blake Canter of Owen River Farm. Blake gave me the grand tour of his small mixed vegetable plot, which is in far east Tallahassee.
One thing that I remember most about my visit with Blake was what has worked for him in controlling the notorious red imported fire ant (Solenopsis invicta). I have heard of many different ways to control these non-native invaders, each with its drawbacks, and, it seems, anecdotally limited success.
For instance, spinosad, a nervous system toxin, has been known to be effective on fire ant populations and is considered safe to use in vegetable gardens. But in practice, I have heard mixed reviews. In my home garden, I either douse the mounds with boiling water (be careful!) or leave my garden hose in the hot sun and scorch them while the water is still hot. But often, I signal defeat, letting them take captive of two corners of my raised beds.
Blake at Owen River Farm makes his fire ant control mixture by combining commercial grade d-Limonene and a hefty squirt of eco-friendly dish soap into five gallons of water. Photo by Molly Jameson.
Blake’s technique on Owen River Farm is using commercial grade d-Limonene, which is a distilled orange oil nerve toxin. Blake mixes one-third cup of d-Limonene with a hefty squirt of eco-friendly dish soap in a five-gallon bucket of water. He then uses this mixture as a drench for fire ant mounds – which he figures is about as effective as boiling water – but much safer and easier to handle (be sure to follow the label carefully when using any product).
Blake goes out early in the morning (when fire ants move slower and queens are usually higher in their nests) and pours the mixture onto the mounds in a spiral formation, from outside in, to minimize escape. He tries to collapse the mound as much as possible, while pouring slowly so it penetrates deeply, with minimal runoff.
Depending on colony size, Blake uses about half the bucket, or more, on just one mound. He warns that he has lost a cucumber plant that was about a foot away to this method, but he knows the ants will often do even more damage, if not sting and bite (they do both!) him hundreds of times, as he works in his vegetable beds.
Blake likes this method because, “I can specifically target the fire ants, and after doing its job, the all-natural orange oil quickly becomes inert. When I used organic ant bait I found that the native ants took up the poison, often times faster than the fire ants. This was particularly bad because native ants are the number one competition for fire ants.”
Blake also points out, “Make sure anyone you recommend this to can identify the difference between fire ant mounds with no center opening to the mound, and native ant mounds, where there is usually an entrance hole in the center of the mound.”
The hardest part, Blake says, is finding the queens. For instance, he says ants often make auxiliary mounds at the base of okra plants, but this is not where the queen resides. The queen will often be in a central mound many yards away from where her workers are foraging. And, unfortunately, these worker ants love easily habitable soft soil, just like in our raised bed vegetable gardens.
Fire ants in a petri dish. Photo by UF/IFAS.
Despite these challenges, last fall Blake drenched colonies whenever he found a mound around his farm (sometimes daily), and after a few weeks he noticed a drastic reduction in fire ant populations. And happily, an increased population of harmless (and even helpful!) native black ants. His brassica (think kale, collards, broccoli, cabbages) transplants were no longer getting girdled by vicious fire ants and he was no longer ending up with dozens of ant bites every time he worked in his beds!
Blake does warn that you must stay vigilant, especially in the summer and fall and after rain events, when the ants become busy building new colonies.
Lastly, Blake also uses his orange oil mixture as a spray for contact killing ants and other garden pests. However, just as with all horticultural oils and soaps (often made from plant oils, animal fats, or petroleum), care must be taken not to burn the foliage of your crops. Blake will sometimes dilute his mixture for this purpose. But just remember, to really stop an ant infestation, you must take down the queen!
For more information on least-toxic garden pest control strategies, read the UF/IFAS EDIS publication “Natural Products for Managing Landscape and Garden Pests in Florida” available at: https://edis.ifas.ufl.edu/in197.