by Mary Salinas | Mar 21, 2018
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
by Les Harrison | Jul 14, 2017
Praying Mantis, Image Credit Les Harrison
Summertime is bug time in the Florid Panhandle. The weather has provided enough rain for the bugs which depend on a supply of foliage and the temperatures have been ideal for a population explosion.
Stink bugs, leaf-footed bugs, grasshoppers, all sizes and colors of caterpillars and many more have been enjoying the lush and plentiful dining options. More than one Panhandle homeowner or gardener has been plagued by the sudden appearance of a hoard of hungry nuisances which are eyeing the menu choices at residences.
Fortunately, nature has a way of eventually balancing all situations when left to its own devices. With the increase of the plant eaters comes a surge in those insects which restrain the excess population.
One of the most easily recognized predator insects is the praying mantis. This beneficial insect is actually a family with multiple members, some of which have been introduced to Florida.
While there are over 2400 mantis members worldwide, Florida is home to eleven. Two of those exotics have been introduced from other regions, but considered non- invasive.
Mantises are thought to have evolved during the Cretaceous period about 100 million years ago, possibly from a predatory cockroach with similar front legs. Their closest surviving insect relatives are cockroaches and termites, both of which they will consume if given the opportunity.
Like many insects, the mantis is equipped with a tough, durable exoskeleton which provides a basis for successful close quarter combat and meal procurement. These hunters have three other advantages which create a severe vulnerability in their prey’s defense and potential for surviving a mantis encounter.
The mantis is an ambush predator which will lay in wait for the victim/meal to deliver itself. The mantis has the instinctive ability to identify and hide in areas with high amounts of prey species traffic.
This insect is a master at stealth and camouflage. The creature’s coloration and linear shape allow it to blend into the earth tones of many settings.
To complement its ability to conceal itself in plain sight, the mantis can hold perfectly still and patiently wait for the oblivious bug to bumble into sticking range. At that precise moment, the mantis is a blur of lethal motion.
The mantis’ forelimbs are a set of deadly spiked vices used to immobilize and secure its target. It extends these spiny levers forward in a raised position which appears as though it is in a mealtime prayer, hence its name.
The kill technique is to impale and restrain the victim with a single stroke of the forelimbs while holding the victim securely to the mantis’ body. On occasion the attempt fails and the mantis has to apply a more direct approach.
This insect’s beak is designed for slicing and tearing its victim’s body. Its jaw muscles provide the power to effectively employ this tool.
Depending on its stage of live, the mantis will eat a wide variety of creatures. Early stage mantises will eat little flies and other tiny insect (including its siblings), but at maturity they will take on small reptiles and amphibians along with a variety of destructive insects.
Female mantises will even consume their prospective mates. Despite its vicious and cannibalistic nature, the praying mantis is the answer to many gardeners’ prayers.
To learn more about praying mantises and other beneficial insects, check out this EDIS site with many articles on various species of beneficial insects.
by Gary Knox | Jun 29, 2017
IPM for Shrubs in Southeastern US Nursery Production Volume II is the third book released by the Southern Nursery Integrated Pest Management Working Group (SNIPM) and includes chapters on hydrangea, loropetalum, holly, rhododendron (including azalea), Indian hawthorn, and weed management. Each chapter covers history, culture and management of the major species and cultivars in production, as well as arthropod pest management and disease management. Within the discussion of these topics, each chapter includes strategies for developing effective IPM programs for key pests and plant pathogens, including tables of fungicides and insecticides for use with these key organisms. While developed for nursery producers, this information also may be useful to landscapers, students, arborists and others.
This free book is downloadable as pdf chapters at
http://wiki.bugwood.org/IPM_Shrub_Book_II.
The first book, IPM of Select Deciduous Trees in Southeastern U.S. Nursery Production, was released in May 2012 and is available for free download as chapter .pdf files at http://wiki.bugwood.org/SNIPM and as an eBook from the iTunes Bookstore https://itunes.apple.com/us/book/ipm-for-select-deciduous-trees/id541182125?mt=11.
The second book, IPM for Shrubs in Southeastern US Nursery Production Volume I, was released in June 2014 and can also be downloaded as chapter .pdf files at http://wiki.bugwood.org/SNIPM or from the iTunes Bookstore at https://itunes.apple.com/us/book/ipm-for-shrubs-in-southeastern/id903114207?mt=11.
The SNIPM Working Group is a multi-disciplinary group of Extension professionals formed to more efficiently and effectively develop and deliver educational programming to the southern U.S. nursery and landscape industry.
by Larry Williams | Feb 25, 2017
Florida farmers produce more fresh tomatoes than any other state. Yet Florida home gardeners find it difficult to grow tomatoes. By changing a few basic practices, home gardeners can increase their chances of success.
My philosophy of growing tomatoes in Florida (mixed with science) is outlined below.
First, I choose mostly determinate varieties that have resistance to key diseases.
Most gardeners are used to growing indeterminate varieties. Farmers mostly grow determinate types. Determinate varieties are more compact and produce most of their crop at one time. You can usually harvest all the fruit in two to five pickings and then pull up the plants. Indeterminate varieties, sometimes referred to as “everbearing” tomatoes, set fruit along a vine stem that continues to grow all season.
Correct variety selection is a must for success with tomatoes in Florida.
One reason home gardeners have a difficult time growing tomatoes in Florida is because of incorrect variety selection. Most popular (indeterminate) tomato varieties lack resistance to Tomato Spotted Wilt Virus (TSWV) and bacterial wilt. These two diseases wreak havoc in home as well as commercial plantings. Amelia, a determinate variety that has TSWV resistance, has started showing up in some retail outlets. For a list of other varieties to look for, consult this publication, “Tomatoes in the Florida Garden”.
Secondly, I plant reasonably early – usually after April 1 (maybe earlier this year due to warm late winter). Tomato plants grow best when temperatures exceed a specific base temperature for a certain number of days (referred to as heat units or degree days). Tomatoes are heat-loving plants that need a long warm growing period to grow from seed to fruit. Optimum fruit set occurs within a narrow night temperature range. Tomatoes produce the largest yields of highest quality fruits when day temperatures are in the range of 80 to 85ºF and when night temperatures remain above 62 but below 72ºF.
Thirdly, I fertilize to produce a healthy, sturdy plant when the plant is young. With the first open flowers, I reduce fertilization (particularly the nitrogen) to about half the original rate. When the first fruits are about two inches in diameter, I reduce fertilization a little more. Once I harvest the first tomatoes, I further reduce the fertilizer to about ¼ the original rate or completely quit fertilizing. Many home growers fertilize tomatoes too much. This results in a big green plant with few tomatoes. This reduction in fertilization is mainly important with the amount of nitrogen being applied. The plant still benefits from adequate potassium.
There are two basic phases of growth in plants – vegetative and reproductive. When a tomato plant begins to produce flowers, it is becoming sexually mature (switching from a vegetative phase of growth to a reproductive phase of growth). Just remember that as plants mature and fruit, the demand for nitrogen decreases. Excessive nitrogen can reduce fruit set and development. Too much nitrogen keeps the plant in a vegetative phase of growth resulting in a big, overly vigorous, green plant with few to no fruit.
As heat, humidity, rains, diseases and insects increase during summer months, tomato production declines. Entire plants may begin to die. At this point, I’m thankful for any production I got. I do away with the plants and find something else to do other than grow tomatoes.
by Carrie Stevenson | Dec 4, 2015
______________________Figure 1. Doveweed patch in St. Augustinegrass sod.__________________________
Ramon Leon, WFREC Weed Specialist
Doveweed (Murdannia nudiflora) is a summer annual weed species that belongs to the dayflower family. Over the last three years, this weed has become an important weed problem in residential lawns and sod production.
This weed has two key characteristics that make it successful. First, its seeds germinate late during the spring when soil temperatures reach 65-70°F. This represents a problem because at this time the effect of preemergence (PRE) herbicides applied in February or March might be too low to provide good doveweed control. Second, the leaves of this weed can be confused with St. Augustinegrass and centipedegrass leaves, and many people do not notice doveweed until the plants are large and are displacing the turf. Doveweed leaves are thick with a shiny rubbery texture. The plant produces creeping stems (stolons), and mowers can break these stolons spreading this weed across the field.
It is very important to keep in mind that doveweed prefers wet areas, so drainage issues or over-watering will favor the establishment and growth of this weed. For this reason, ensuring irrigation is not excessive is a key management practice to control this problem. Another cultural practice that plays a major role on doveweed management is mowing. Mowing too short and too frequently will favor doveweed because its leaves will grow horizontally avoiding the mower blades. Chose a mowing height that allows good ground cover , yet only removes a third of the turf leaf blades.
___________Figure 2. Individual doveweed plant showing flowers, fruits, and stolons with root in nodes.________
Control
Doveweed is easier to control before emergence than when plants are well established. Atrazine is one of the most effective herbicides to control doveweed. A maximum rate of 1 lb. of active ingredient (ai) per acre (A) and no more than 2 lb. ai per year are recommended to achieve both adequate control and avoid turfgrass injury. Atrazine should be applied right before or soon after doveweed emerges to maximize control.
For PRE control, S-metolachlor (Pennant Magnum™), dimethenamid-P (Tower™), and indaziflam (Specticle™) are herbicides that can considerably reduce doveweed establishment, especially if the application is done closer to doveweed emergence timing. These herbicides also provide good control of other important weed species such as crabgrass and goosegrass, which emerge earlier in the spring. In order to control early emerging weeds and doveweed, split applications are preferred. For example, the first application is done at the end of February or early March and the second one 4 to 6 weeks after. In this way, we can extend PRE control until doveweed starts emerging.
If we observe doveweed emerging after PRE applications, we have several postemergence (POST) herbicides that will provide control, as long as the plants are less than 2 inches in size and have not produced stolons. Products containing 2,4-D and dicamba can provide fair control of doveweed. However, repeated applications or applications in combination with other herbicides will be required for adequate control. There are commercial products with formulations that combine 2,4-D or dicamba with other herbicides such as mecoprop-p, carfentrazone (Quicksilver™), thiencarbazone and iodosulfuron (e.g., Celsius™, Tribute Total™). This type of three− or four−way combination can provide enhanced doveweed control. If doveweed has fully displaced the turf in spots, it is probably easier and more effective to kill doveweed with a directed application of glyphosate (RoundUp™) and re-seed or re-sod the area.
Because doveweed seeds can live for several years in the soil, it will take two to three years of continuoous control to eliminate doveweed populations. Although herbicides are useful tools to control doveweed, the most important factor to prevent doveweed problems is to have vigorous healthy turf. Doveweed requires a lot of sunlight, so if the turf effectively shades the ground, doveweed will have a hard time growing and producing new seed.
For more information on managing turf weeds download:
