Why are the Azaleas “Bleaching Out”?

Why are the Azaleas “Bleaching Out”?

Leaf with color fading

Damage caused by azalea lace bug, Stephanitis pyrioides (Scott), feeding. Photograph by James. L. Castner, University of Florida. Severely damaged leaves become heavily discolored and eventually dry or fall off. Symptoms may sometimes be confused with mite injury, but the presence of black varnish-like excrement, frequently with cast skins attached, suggest lace bug damage (Johnson and Lyon 1991).

You may be noticing the color disappearing from your azaleas right now. Do your azaleas look bleached out from a piercing-sucking insect. The culprit is probably azalea lace bug, Stephanitis pyrioides. This pest overwinters in eggs on the underside of infested leaves. Eggs hatch in late March and early April. The insect then passes through five nymphal instars before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult and there are at least four generations per year. Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly-hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.

Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed from the underside of the leaf. Lace bug damage to foliage detracts greatly from the plant’s beauty, reduces the plant’s ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions. The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.

However, lace bugs often go undetected until the infested plants show severe damage sometime into the summer. By then several generations of lace bugs have been weakening the plant. Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.

Adult lace bugs are flattened and rectangular in shape measuring 1/8 to 1/4 inch long. The area behind the head and the wing covers form a broadened, lace-like body covering. The wings are light amber to transparent in color. Lace bugs leave behind spiny black spots of frass (excrement).

Insect with clear wings.

Adult azalea lace bug, Stephanitis pyrioides (Scott), and excrement. Photograph by James. L. Castner, University of Florida.

Lace bug nymphs are flat and oval in shape with spines projecting from their bodies in all directions. A lace bug nymph goes through five growth stages (instars) before becoming an adult. At each stage the nymph sheds its skin (molts) and these old skins often remain attached to the lower surface of infested leaves.

Small dark-colored insect on leaf with shiny black spots.

Nymphs of the azalea lace bug, Stephanitis pyrioides (Scott), with several cast skins and excrement. Photograph by James. L. Castner, University of Florida.

Azalea lace bug eggs are football-shaped and are transparent to cream colored. Lace bug eggs are found on the lower leaf surface, usually alongside or inserted into a leaf vein. Adult females secrete a varnish-like substance over the eggs that hardens into a scab-like protective covering.

Other plant species, such as lantana and sycamore, may have similar symptoms. But, realize that lace bugs are host specific. They feed on their favorite plant and won’t go to another plant species. However, the life cycle is similar. Be sure to clean up all the damaged leaves. That’s where the eggs will remain for the winter. Start next spring egg-free.

For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm

Japanese Plum Yews for the Landscape

Japanese Plum Yews for the Landscape

We are always on the lookout for an attractive plant for our landscape.  At the nursery, some plants have a more difficult time gaining our attention. They may not be as showy, possessing neither colorful flowers nor bold foliage.  In these cases, we could be missing out on low maintenance plant that offers its own form of beauty in the right landscape spot.
One plant that I love is the Japanese plum yew (Cephalotaxus harringtonia), especially the spreading form ‘Prostrata’.  In the nursery container, this plant is nothing special but once established in the landscape it performs well.  The conifer type leaves are an attractive dark green and the ‘Prostrata’ selection is low growing to about 2 to 3 feet.  An advantage too is that growth is slow so it won’t take over or require routine pruning.
Japanese plum yews grow best in partial shade and once established will be fine with rainfall.  For a shadier side of the home, the spreading plum yew has a place as an evergreen foundation plant too.

Japanese plum yew in a shaded garden. Photo by Beth Bolles, UF IFAS Extension Escambia County

If the ‘Prostrata’ selection is too low growing for you, consider the ‘Fastigiata’ cultivar that will grow upright to about 8 feet with a 5 foot spread.

A year old planting of upright Japanese plum yew in filtered light. Photo by Beth Bolles, UF IFAS Extension Escambia County

Fireflies – Nature’s Fireworks

Fireflies – Nature’s Fireworks

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.

July Is Smart Irrigation Month

July Is Smart Irrigation Month

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.

Rain collecting device with expanding cork disks inside.

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.

Perennial Peanut Lawn:  Two Years Later

Perennial Peanut Lawn:  Two Years Later

‘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.

Roadside Wildflower Areas Provide Beauty for Travelers

Roadside Wildflower Areas Provide Beauty for Travelers

Wildflowers near Live Oak, Florida. Image Credit, UF / IFAS

Florida (“land of flowers” in Spanish) is and has always been full of flowers, and countless civic and public organizations work diligently to protect and promote the beauty of our natural ecosystems. Did you know that the Florida Wildflower Foundation works with the Florida Department of Transportation (FDOT) to preserve wildflower areas on state-maintained roads throughout Florida? This effort really took off in the 1960’s when non-native Crimson clover started sprouting among sod planted by the state FDOT, and has grown into a much larger statewide initiative. The state wildflower license plate program provides funding for these efforts.

Wildflower areas along highways not only improve beauty on the roadsides, but provide habitat for countless pollinator insects that drive our $1.2 billion (annual) citrus and agricultural industries and our own backyard landscapes. In addition, leaving no-mow areas along highways saves money on mowing costs, reduces soil erosion, and improves air quality.

The state wildflower license plate supports wildflower preservation efforts statewide. Photo credit: Florida Wildflower Foundation

Wildflower viewing is typically best in the spring and fall, and particularly in areas (such as state parks and forests) that have been recently managed by prescribed fire. Many low-lying areas are home to beautiful native species such as pitcher plants, hibiscus, and meadowbeauty. Be very careful when viewing or stopping to see roadside wildflowers, and be sure to find designated parking areas to prevent accidents. To find a map of the wildflower trails, visit your local tourism bureau or go online at https://flawildflowers.org/protect/.

Currently, every Panhandle county from Jefferson County east has designated wildflower areas. The Escambia County Board of Commissioners passed a wildflower ordinance supporting the program, and a committee met in May 2019 to determine more areas of the county appropriate to set aside for the program. As opposed to planting new wildflowers, the program prioritizes conserving roadside areas that already support healthy wildflower populations. If you know of good candidates for preservation on state roads in Escambia or any other panhandle county, please contact me (ctsteven@ufl.edu) or Liz Sparks (liz.aparks57@gmail.com) with the Florida Wildflower Foundation.