by Mark Tancig | Jul 11, 2019
An adult firefly showing off its characteristic beetle wings and bioluminescent abdomen. Credit: Art Farmer, Creative Commons.
Many of us have memories of warm summer nights watching fireflies. Some of us might have even chased and caught a few to put in mason jars for observation, fascinated by their glowing abdomens. Floridians have the best chance to see these unique insects, as we have more known species than any other state. Recently, I’ve had many folks say that they see less fireflies these days, which got me looking into how these creatures live and what researchers know about their numbers.
Fireflies are actually a type of beetle in the Lampyridae family. They go through complete metamorphosis, meaning their immature larvae look completely different than the adults. A very unique characteristic of the family is the ability to produce light, known as bioluminescence. They do this in a very efficient way, creating very little heat, through the reaction of luciferin and luciferase along with oxygen, some energy, and other compounds. These light-producing compounds serve a dual purpose, warding off predators and attracting mates. The larvae of all Lampyridae benefit from the offensive taste of the compounds while only some adult Lampyridae use bioluminescence to attract mates. Each species of firefly has specific patterns of flashes. Males have the showiest light displays while females use more conservative light shows to signal back to potential mates.
Firefly larvae taste bad to predators due to the compounds that produce light. Credit: Gerald J Lenhard, LSU, bugwood.org.
Larvae of fireflies live in the soil and feed on slugs, snails, earthworms, and other soft-bodied insects. The larvae develop in the soil during cooler months, preferring moist habitats, and emerge as adults in the late spring to early summer. Some species may emerge in the early spring. Adult fireflies feed on nectar and honeydew, though some females prey on smaller firefly species by fooling males close to them through light signaling. Adults with the ability to produce light are active at night, while non-bioluminescent adults are active during the day.
An adult firefly. Credit: Mirko Schoenitz, iNaturalist.org.
Entomologists specializing in fireflies have raised the concern that these classic summer-time insects are in decline. Reasons for the decline are associated with increased urbanization. Loss of suitable habitat and increased pesticide use, including broad-spectrum insecticides for home lawn insect control, negatively affect firefly larvae living in the soil. Researchers also point to urban light pollution as another cause. The ever-glowing night sky in populated areas, originating from house lights, ball fields, parking lots, and roadways, disturb firefly communication and reproduction.
UF/IFAS infographic about fireflies. Credit: UF/IFAS.
Homeowners can help fireflies by leaving small patches of unmanaged landscaped areas, such as along property lines, and only using insecticides when absolutely necessary. If pesticides are needed to control lawn and garden pests, the use of more selective, low-toxicity products is preferable. Turning off unnecessary outdoor lighting is another step homeowners can take to encourage firefly populations. Residents of homeowner associations can work together to minimize excess lighting community-wide, saving electricity and maybe even fireflies.
For more information on fireflies and best practices to control lawn and garden pests, contact your local county extension office.
by Sheila Dunning | Jul 11, 2019
The Irrigation Association (IA) kicks off the official start of this year’s campaign on Tuesday, July 9, 2019. The initiative promotes the social, economic and environmental benefits of efficient irrigation technologies, products and services in landscape, turf and agricultural irrigation.
Irrigation (agricultural and turf/landscape) accounts for 65-70% of total freshwater use in the United States. According to the Environmental Protection Agency’s (EPA) WaterSense program, the average American family household uses more than 300 gallons of water per day; roughly 30% of this occurs outdoors. Efficient landscape irrigation systems and practices dramatically reduce water being lost or wasted.
The starting point for improving the efficiency of a home landscape sprinkler system is to calibrate each zone (http://ufdc.ufl.edu/IR00003389/00001) and make adjustments and repairs. That includes the rain shut-off device.
Florida is one of the few states with a rain sensor law. The most recent version of the statute (2010) states the following: “Any person who operates an automatic landscape irrigation system shall properly install, maintain, and operate technology that inhibits or interrupts operation of the system during periods of sufficient moisture.” (Florida Statute 373.62). Regardless of the water source or age of the system, all in-ground irrigation systems must be connected to a functioning rain sensor of some kind.
Expanding disk Rain Sensor
Expanded disk devices are the most popular rain sensor due to their low cost, ease of installation, and low maintenance. Traditionally, they are wired into the controller, but a wireless version allows for quicker installation and mounting up to 300 feet from the controller. These “mini-click” sensors contain disks made of cork that absorb rainfall and expand, triggering a pressure switch. The disk cover is rotated to adjust for the predetermined amount of rainfall required to trigger the switch. It should be set on ½ – ¾ inch, depending on soil type and rooting depth of irrigated plants. The switch continues to interrupt the scheduled controller as long as the disks are swollen. When the rain stops, the disks begin to dry out. Once they have contracted, the switch closes and the regularly scheduled irrigation cycle begins where it left off before the interruption. These small cork disks wear out in Florida’s heat and need to be replaced. By checking and repairing the sensor parts, the sprinkler system will operate much more efficiently. We have all seen irrigation systems running in pouring rain. Keep yours maintained to avoid this needless waste of water.
So, join the kids this summer. Go outside and play in the water. Turn on the sprinkler system and check it out. July is Smart Irrigation Month. Let’s see how efficient you can make your system and reduce the water waste in Florida.
by Daniel J. Leonard | Jun 25, 2019
‘Needlepoint’ Perennial Peanut in the author’s lawn.
What began as my journey toward a turf-less lawn in September of 2017 is finally beginning to come together! In the fall of 2017, I installed about 120 one-gallon-sized ‘Needlepoint’ Perennial Peanut (Arachis glabrata) plants, purchased from Sunset Specialty Groundcovers in Live Oak, FL, on roughly 20” centers in my front lawn, an oddly shaped (650 ft2) patch of ground that had been previously filled with spotty centipedegrass and a healthy and diverse weed population. 18 months later, the peanut has almost completely filled in, shaded out all the weeds, and blooms nonstop!
Looking back, I definitely learned a few lessons the hard way. First, you should mulch bare ground in between plants at time of installation. Because there are few herbicides labelled for residential use on this crop and I didn’t want to experiment on my new “lawn”, I spent a lot of time on my hands and knees (much to the amusement of my neighbors and folks driving by) pulling weeds in the first two years that could have been prevented with mulch. Second, have a plan for keeping the perennial peanut in bounds once it has filled in the area it was supposed to and begins to travel into adjacent landscaped beds! The area my peanut inhabits is surrounded on two sides by inescapable concrete. It was on the other two sides, however, that I have had to improvise after they came under siege (literally under, because perennial peanut spreads by underground rhizomes). Installing some sort of edge blocker at planting and vigilance with routine mechanical edging is a must to keep it in bounds! Third, I recommend that you have a counter-argument prepared when the peanut goes dormant in the winter and your wife asks why the yard is bare dirt!
‘Needlepoint’ Perennial Peanut overhead shot showing complete ground coverage in the author’s lawn.
Overall, though there are a couple of things I would have done differently, I’m extremely pleased with my lawn of perennial peanut. It is absolutely stunning in the warm months, incredibly low maintenance, and unique! Plant some today!
As always, if you have any questions about perennial peanut or any other plant/crop, contact your local UF/IFAS Extension office.
by Larry Williams | Jun 25, 2019
Adult and nymphs of mole crickets. Photo: Julie McConnell, UF/IFAS
The best time to treat for mole crickets is during June through July. But don’t treat at all if mole crickets have not been positively found and identified in the affected lawn areas.
Don’t worry about the adults that are seen flying around lights in the evenings or about the mole crickets found dead in swimming pools this time of year. They are in a mating phase and are doing very little to no damage to lawns during late winter and spring.
We can take advantage of the fact that there’s only one generation per year in North Florida. The eggs will have all hatched by mid to late June. At that time, you’re dealing with young mole crickets that can’t fly and that are much more susceptible to the insecticides designed to kill them. Mole crickets spend winter as adults in the soil. In late February and March, adults emerge and begin mating. Shortly after mating, males die and females fly to suitable areas for egg laying. Mated females deposit eggs in tunnels. After depositing her eggs the female dies. Attempting to control adult mole crickets during this mating period a waste of time, money and product. Plus, adult mole crickets are difficult to control and can easily fly out of treated areas.
You can easily determine if mole crickets are the cause for your lawn problem by flushing them out with a soap and water mixture.
Mix 1½ ounces of a lemon scented liquid dish-washing soap in two gallons of water in a sprinkling can or bucket. Pour the soapy water over an area approximately four square feet and count the number of mole crickets that emerge. It only takes several minutes for mole crickets to crawl to the surface after the soap treatment if they are present. Repeat the process around the yard where you suspect mole cricket problems. If you flush an average of two to four crickets are flushed out per site, control may be needed.
There are a number of insecticides on the market to control mole crickets. But before using any product, first identify the problem as mole cricket damage by using the soap flush technique. Then choose a lawn insecticide that lists mole crickets on its label. And finally read the label carefully for use directions, application techniques, irrigation requirements and precautions.
For more information on mole crickets, including recommended insecticides and other non-chemical control options, contact the UF/IFAS Extension Office in your County or access the following links.
Insect Pest Management on Turfgrass
Shortwinged Molecricket
Mole Cricket IPM Guide for Florida
by Matt Lollar | Apr 9, 2019
The Evidenced-Based Zoysiagrass Management Workshop is returning to Milton on April 23 at the University of Florida – Milton Campus. Attend to get updates on managing zoysiagrass and to earn CEUs. Register at: UF/IFAS Evidence-Based Zoysiagrass Workshop
by Logan Boatwright | Mar 26, 2019
Hurricane Michael Damage – Photo Credit Larry Williams
The aftermath of Hurricane Michael has many homeowners preparing their landscapes for the upcoming season. Several have called the office in need of a home visit because they want ideas of what to replant with and how to kill the weeds that have popped up. One common question is, “What trees can I plant that are fast growing and has plenty of shade?” Before I answer their question, I ask them, “Are you planning for future storms or not?”
Trees that are considered ‘fast’ growing are not necessarily the best choice for future storms. Many of the fast growing trees can be easily uprooted, break easily in strong winds, are more prone to decay, and/or are rather short-lived (<50 years old). Additionally, a missing structural pruning plan for young and mature trees will increase the chances of fallen trees. Homeowners can expect to replant trees once again if these characteristics are likely. Keep in mind that no tree is absolutely wind-proof since other factors need to be ideal for wind-resistance. Trees like laurel oak (Quercus laurifolia), water oak (Quercus nigra), cherry laurel (Prunus caroliniana), bradford pear (Pyrus calleryana), and pecan (Carya illinoensis) are some to be cautious of when replanting for wind resistance.
A few tips for homeowners re-planting hurricane damaged trees:
- Plant trees with higher wind resistance in groups with adequate soil space and soil properties.
- Prevent damage to the roots.
- Have a variety of native species, ages, and layers of high-quality trees and shrubs.
- Some of the best trees a homeowner should consider replanting with could be live oak (Quercus virginiana), southern magnolia (Magnolia grandiflora), baldcypress (Taxodium distichum), river birch (Betula nigra), and Japanese maple (Acer palmatum). A more in-depth look at wind resistant trees can be found by reading Wind and Trees: Lessons Learned from Hurricanes.FOR 118
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