Anyone who has had a treasured palm tree annihilated by palmetto weevils (Rhynchophorus cruentatus) knows the pain of losing a long-lived tree from the home landscape. These large, native weevils are adept at working unnoticed inside a palm to the point of terminal damage. Typically, by the time you notice that the tree is declining and fronds begin to turn brown there is likely no hope of salvaging the situation. By then the larval grubs have already damaged the tree’s growing bud to the point of no return. At this stage the recommended procedure involves removing the tree, cutting it up and burning it to prevent the invading long-snouted critters from moving over to neighboring palms.
Color and size of adults is quite variable.
However, as frustrating as this is, if we step back and look at the bigger picture it is apparent that even our most aggravating native insect pests are part of the natural web of life and local plants have adapted to survive these “give and take” relationships on the population scale.
Palmetto weevils establish in a new tree when adult females lay their eggs in the crown of the tree and larvae hatch to burrow into the soft terminal bud. It is larval feeding that does the lethal damage. Larvae are large, white, legless grubs that can reach lengths of six-seven centimeters. When larvae are mature they create a cocoon inside the tree from tree fibers and pupate there before hatching into adults to start the cycle over. Grubs can be found in any part of the tree but really need the softer, growing parts for food, such as in the base of the living fronds and the terminal bud.
Weevil damage at base of frond.
The condition created by these burrowers is often referred to as “popped neck,” where the top of a palm tree dies and caves over. If you are in the process of removing a dying or dead palm due to the crown dying it would be a good idea cut through the top section with a chainsaw to see if weevil damage is evident in large (about ½ inch) diameter tunnels. If a live specimen of an adult can be captured in a jar it would be worth a visit to your local Extension office for a positive identification to make sure you aren’t dealing with another similar species of non-native weevil that has not been documented in Florida yet. The red palm weevil (Rhynchophorus ferrugineus) has now been found in the U.S. at Laguna Beach, California. Coloration varies by individual bug but a positive i.d. can be obtained by sending the specimen to UF’s laboratory in Gainesville. For further information on palmetto weevils refer to the EDIS fact sheet at this web link.
Dodder vines covering an oak seedling. The vines always wrap counterclockwise. Photo Credit: Jed Dillard
Vampires of all types and genetic modifications are hot topics these days, and a common, but uncommon looking and acting Florida weed may have combined the two subjects. Dodder, a native invasive, parasitic plant, reproduces by seed but does not have enough leaves or chlorophyll to feed itself. Its thin, golden vines and tendrils must attach to a host plant in the seven to ten days it takes the plant to exhaust the carbohydrates in its small seed. Once dodder attaches to a plant, it connects to the inside of the host using small structures called haustoria which press into the stem and begin to draw nutrients from the host. At this point the dodder roots atrophy.
Single dodder plants are not a big issue, but once enough plants build up in an area large mats of vines can reduce growth and vitality of the host. (See photo) Frequently, the pest has reached this stage before it’s noticed, leaving the problem of treating a rootless, nearly leafless plant that is wrapped around a more desirable plant. Not only are the typical routes of herbicidal entry minimized, the hosts are at as much risk as the pest. Hand removal may be practical in small outbreaks, but the plant can reemerge from any small piece left attached to the host. In most cases, the solution is to destroy the host and the dodder and apply a pre-emergent herbicide to stop germination from any seeds remaining in the soil.
What about the GMO angle?
Work published last year in the journal Science by Jim Westwood of Virginia Tech reveals the dodder plant exchanges messenger RNA with tomato and Arabidopsis plants when it extracts the juices from the host plant. Scientists speculate this exchange of genetic material makes the host plant less resistant to attack by the parasite and that this holds promise for learning more about controlling other parasitic plants.
If plants are exchanging messenger RNA, a critical part of protein and gene synthesis, what other genetic exchanges are occurring naturally without our knowledge? Scientific progress hinges on unpredictable events and sources. Learning more from a “vampire weed” that has no easy means of control may be one of those.
To see the dodder plant go from seed to golden mat, watch this time lapse video Virginia Tech has posted on Vimeo. http://www.vtnews.vt.edu/articles/2014/08/081514-cals-talkingplants.html
Monitor your ponds closely throughout the spring and make any necessary herbicide applications before weed growth becomes too excessive. Photo Credit: Mark Mauldin
Similar to Goldilocks’ porridge, water temperature doesn’t need to be too hot or too cold, it needs to be just right for using aquatic herbicides (70o – 80o F). Here in Florida, these optimum water temperatures occur in the spring. Water temperature largely regulates the growth of most aquatic weeds; cool temperatures slow or stop growth and warm temperatures promote growth. Keeping this simple principle in mind can help determine when to use aquatic herbicides.
Generally speaking, aquatic herbicides are not used when water temperatures are below 60o F. When water temperatures are this cool most aquatic weeds are not actively growing. For herbicides to be effective the target plants must be actively growing. Applying herbicides too early in the spring is generally not an issue because winter dieback can make many aquatic weeds hard to find when water temperatures are cool. The weeds are out of sight and out of mind. The much more common issue is waiting too long before attempting to control weeds.
As water temperatures climb above 60o weeds begin to grow. Unfortunately, they often times grow unnoticed throughout the spring until they become completely out of control in the summer. By this point, control, even using herbicides, is a monumental task. If at all possible, control weeds early in the growing season.
As plants grow they are able to build up energy reserves, making them more difficult to control. The longer they are allowed to grow the stronger and more difficult to control they become. Controlling weeds earlier in the growing season eliminates this problem.
Similarly, as the growing season progresses plants produce more and more biomass. If an herbicide is applied and the weeds are killed large amounts of decomposing plant material in the water can cause problems. The decomposition process uses oxygen; dissolved oxygen can drop to levels that are hazardous to fish and other aquatic species. The more plant material that is present when herbicides are applied the bigger concern this becomes. Applying herbicides earlier in the growing season, before large amounts of biomass are produced, can help lessen this problem.
Aquatic weeds can grow rapidly when temperatures are warm. Don’t let them get out of control before you begin control efforts. Photo Credit: Mark Mauldin
Further compounding the issue, warm water is physically able to hold less dissolved oxygen than cooler water. Late in the summer pond water can be very warm with low concentrations of dissolved oxygen even before large amounts of decomposing plant material are added.
To help reduce the risk of oxygen depletion never treat more than ½ of a pond at one time, if weed growth is already substantial treat no more than 1/3 of a pond at one time and always allow 10 -14 days for oxygen recovery between treatments. Also, avoid treating on cloudy days, another factor that can lead to lowered dissolved oxygen.
Aquatic weed control will be easier and more effective if you monitor your pond throughout the spring and make any needed herbicide applications early, before the weeds have grown too large and the water is too warm. Consult your county extension agent for assistance determining what aquatic weeds you have and if treatment is necessary. Always read and follow all label directions when using any herbicide.
As we left the winter months and headed into spring I was expecting a lot of new blooms, new animal tracks, and more live encounters with wildlife… and then the rain began. I do not know if the entire panhandle has been getting what Pensacola has but the rain has been nonstop for over a week now. I track rain days for a water quality project and for the first three months of 2015 the number of days during a month where it rained was between 23-30%. We are about half way through April and so far it has rained 61% of the days. WELL… rain or shine we will make this hike and see what is happening on our barrier island.
Hole left by a sand castle architect. These can be problems for wildlife and rescue vehicles. Photo: Rick O’Connor
The first thing I noticed when I began the trip along the Gulf was this large hole left by a sand castle architect. These can be problematic for some forms of wildlife, including sea turtles, but they can also be a problem for rescue and turtle watch vehicles. Please enjoy the beach and make awesome sand castles, but when you are finished please fill the hole.
Sargassum is floating form of brown algae. Notice the “air bladders” (pneumatocyst) Photo: Rick O’Connor
A tropical seed commonly referred to as a sea bean. Photo: Rick O’Connor
The line of seaweed and debris along the surf zone is called wrack. Photo: Rick O’Connor
The line of seaweed and debris that washes ashore during storms is called the wrack. For the most part it is natural material and provides the nutrients needed for many of the high energy shoreline plants to grow. Many of the beach animals found in the berm and primary dune depend on this wrack as well. Many locals and visitors find this material and eye sore and, at times, producing an unpleasant odor. But this material is an important part of the beach ecology. Sargassum is a drifting member of the brown algae, sometimes called “gulfweed”. It possess small air bladder structures called pneumatocysts that allow it to remain at the surface of the open Gulf where the sunlight is. These large offshore mats of Sargassum have been targets for local fishermen for decades. Many small invertebrates live in these drifting mats and these are targets for small fish, which in turn are targets for even larger sport fish. They are also the hideaway for sea turtle hatchlings. When the little guys head for the Gulf after hatching this is where they are heading. Large ocean currents, including the Gulf Stream, push Sargassum into large mats in the middle of the open ocean. The area within the Atlantic where this happens in known as the Sargasso Sea. If you get a chance this summer, grab a small hand net and mask when the Sargassum is just offshore. Collecting you may find a lot of cool interesting creatures. Sea Beans is a generic word for a variety of tropical seeds that wash ashore in the northern Gulf. Some of these may sprout, including mangroves, but most will not make it through our winters.
The Blue Button Jellyfish is a tropical cousin of the Portuguese man-of-war. Photo: Rick O’Connor
The Portuguese Man-of-War is one of the more venomous jellyfish in Florida waters. Photo: Rick O’Connor.
A variety of shorebirds utilize the wrack. Photo: Rick O’Connor
One of the more venomous jellyfish in Florida waters is now making its way onto our shores. The Portuguese man-of-war, named for the many “guns” this animal possess, is well known by locals but not so much by some of our visitors. The man-of-war is actually not one animal but a colony of sedentary polyp jellyfish that produce an inflated bag which floats at the surface carrying them across the sea. The dark blue tentacles hang down into the water column where passing fish are stung and consumed. Each of the polyps have connecting stomachs which helps move the food around to the whole colony. The sting of this jellyfish is quite painful and should be avoided. When they arrive life guards will usually fly a purple flag.
Their close cousins, the Blue Button Jelly, is very similar to the man-of-war albeit they are much smaller and the venom is not as potent. They are more tropical and not common along the northern Gulf but in recent years more have been washing ashore; they are here now.
A variety of plastics ends up in the Gulf. Each is a potential problem for marine life. Photo: Rick O’Connor
Pieces of plastic ribbon resemble jellyfish tentacles and are frequently consumed by sea turtles. Photo: Rick O’Connor
One of the bigger issues are oceans are facing are discarded plastics. These materials takes years to decompose and are found in all oceans and seas. Even some distant isolated islands have huge piles of this form of marine debris. Plastics can entangle marine organisms or they may actually swallow it, plugging their digestive system and eventually starving them. We encourage locals and visitors alike to help with this problem by taking your trash with you and discarding it in a location where it will not reach the Gulf.
This ephemeral pond formed around a small dune which becomes a temporary island. Photo: Rick O’Connor
The Chinese tallow is an invasive species the entire state is dealing with. Photo: Rick O’Connor
With the heavy rains of the last week ephemeral ponds have formed on parts of the island. These small pockets of freshwater can be “manna from heaven” for many island residents, particularly the amphibians. I have been hiking this section of Pensacola beach for years, leading field trips for all sorts of groups. I have never seen this Chinese Tallow until today. Also known as the “popcorn tree” due to its unique looking fruit, this plant is listed as an invasive in the state of Florida and is very aggressive. I did not see any others and will seek permission to remove it before it spreads to other dunes and out competes the native plants.
One of the few plants blooming in April, the Spiderwort is a common weed in many lawns. Photo: Rick O’Connor
The blossoms of Conradina first appeared in February. They are all but gone this time of year. Photo: Rick O’Connor
I was actually expecting more flowers to be in bloom this month but there were few. The Conradina, which have been in bloom since February, have lost most of its blossoms. The “new kids on the block” are the Spiderwort, the Primrose, the Sandhill Milkweed, and the Devil’s Joint Cactus.
There are a variety of primrose that grow on our barrier islands. They are beginning to bloom now. Photo: Rick O’Connor
New growth on a pine tree. Photo: Rick O’Connor
The Sandhill Milkweed. Photo: Rick O’Connor
The Sandhill Milkweed is one of the plants used by the monarch butterfly to gain fuel for their great flight across the Gulf to Mexico. The milky toxic sap of this plant is consumed by the monarch caterpillar but it does not harm it. The chemical toxins therefore become a defense for the monarch and the butterfly has earned the respect of many birds; though it may be a trial and error learning experience.
A decomposing log is a microhabitat for many organisms. Photo: Rick O’Connor
New growth on a live oak. Photo: Rick O’Connor
Most environmental centers, state and federal parks, leave fallen trees where they lie. The tree is actually a storage house of nutrients and full of cavities that can be used by a lot of organisms within the beach community.
The mysterious “drags” we have seen the last three months were not to be found in April. Photo: Rick O’Connor.
The beautiful yellow bloom of the Devil-Joint cactus. Photo: Rick O’Connor
This month the weather was warm enough for me to venture into the Salt Marsh. Salt marshes are wetlands but differ from swamps in that the dominate plants are grasses, not trees. Our local salt marsh is dominated by two species of grass, the Smooth Cordgrass, and the Black Needlerush. There are many other plants that exist here but these are the most common. This particular marsh is dominated by Black Needlerush. Salt marshes are one of the most productive systems on the planet, producing tons of organic material annually. 90% of the commercially valuable marine species spend part or all of their lives here. There are many unique species to this system as well. Today the water was crystal clear but I saw few fish. I expect as it gets warmer we will see more. It is very possible that with the heavy rains that they have moved to deeper, saltier spots in the Sound.
It’s warm enough to enter the salt marsh. Photo: Rick O’Connor
The marsh periwinkle is one of the more common mollusk found in our salt marsh. Photo: Rick O’Connor
The Marsh Periwinkle is an interesting guy. This snail will crawl up the stalks of marsh plants during high tide to avoid predators like blue crab and diamondback terrapins. Both of these predators appear to be on the decline and it will be interesting to see how this impacts the ecology of the marsh. At low tide the periwinkles descend and feed on the organic leaf litter on the muddy bottom.
This dewberry has flowered and the dark fruit will be ready next month. Photo: Rick O’Connor
Gracilaria is a common epiphytic red algae growing in our seagrass beds. Photo: Rick O’Connor
Black Needlerush is one of the two dominant plants of our salt marshes. Photo: Rick O’Connor
Though it has a white appearance, Gracilaria is a member of the red algae group. This algae grows on seagrasses as Spanish moss grows on oaks. The plant is usually kept in check by herbivorous grazers, such as green sea turtles, but in recent decades the number of predators have declined and the amount of nutrient runoff has increased. This has sparked a increase in the growth of this algae and, in some cases, to the determent of the seagrass itself.
This eroded pine tree gives evidence of the ever changing shorelines of our barrier islands. Photo: Rick O’Connor
This submerged mound of peat is the remnants of a salt marsh which is now below sea level. Photo: Rick O’Connor
These photos of peat and the eroded tree are indications of a changing shoreline. Due to storms, boat wake, and time, the shoreline of Santa Rosa Island, like all barrier islands, is changing. Peat is actually the remnants of an old salt marsh that has now pass the high tide line and is within the Sound.
Trash left behind by those enjoying the beach. Photo: Rick O’Connor
We encourage those who pack it in… to pack it out. Photo: Rick O’Connor
As the weather has warmed and spring break has fallen upon us I have noticed an increase in the amount of trash on this hike, both the Gulf of Sound sides. We encourage locals to take their trash with them and encourage visitors to do the same. Let’s try to keep our waste out of our waters.
I am expecting some animal nesting in May. We will see what we find. Until then.
Resurrection ferns are found in many mature hardwood trees in north Florida. This fern is an air plant which prospers on skimpy amounts of water and plant nutrients.
One of the wonderful features of spring is the return of green to the branches of many trees in north Florida. Cypress, poplar, cherry and many others have been defoliated by the cool season which is now retreating.
Buds are breaking everywhere deciduous trees reside and changing the complexion of the landscape. Every day the browns and grays are giving way to intensifying shades of green.
Aside from the pines, magnolias and live oaks, there has been green in the branches of some hardwood trees which went through the winter. Resurrection ferns have remained green in their sheltered perches as the seasons change.
Pleopeltis polypodioides, the scientific name for this native fern, has easily flourished through the recent winter with sufficient moisture. This creeping, coarse textured fern is commonly found in the southeastern United State, but also in some African locations.
It has been commonly identified as a resurrection fern because it has the capacity to survive long periods of drought. During dry times the leaves brown and wither, but the roots and leaves survive by stingily conserving water.
When rains return this fern quickly regenerates by promptly circulating water to the leaves through the plants highly efficient vascular system. To the casual observer, it appears to return from the dead in about a day.
The resurrection fern is an air plant, or epiphyte, which attaches itself to other plants. It receives the necessary plant nutrients for growth from several sources.
Bacterial activity on the outer surface of its plant host’s bark is a major contributor. The outer bark layer of many plants and trees is in the process of being shed and is an ideal location for this fern to grow.
Other tiny particles of nutrients are delivered through rain water and on the breezes. Though meager in life sustaining supplies, the resurrection fern flourishes in this harsh environment where most plants would quickly die.
Though usually located on tree branches, resurrection ferns are sometime seen growing on rocks, bricks or deadfall logs. It is not rare to see this fern growing with another native epiphytic plant, Spanish moss.
This plant’s root system are tiny and shallow, as could be expected of a fern which grows on the outer layer of bark. It uses an intricate mesh of rhizomes which meander just beneath the bark’s surface.
These rhizomes are part of the ferns ability spread along the branches and colonizes new sites on the tree or plant. Periodically the roots will emerge on the bark’s surface and sprout leaves.
The other method of propagation and species preservation is through spores which are produced on the underside of the leaves. Most leaf tips have a mechanism to generate a high volume of tiny wind delivered spores.
During summer and early autumn, the spores ripen and are scattered on the prevailing breezes. While only a tiny fraction make it to a hospitable site, the ones which do quickly establish themselves.
So if 2015 produces a dry or wet summer, resurrection ferns will be here. If only other plants were as easy to tend.
Cogongrass Photo Credit: Chris Evans, Illionois Wildlife Action Plan, www.bugwood.org
Cogongrass is one of the 10 worst weeds in the world. This grass is an aggressive grower and forms colonies causing loss of productive forest areas, severe degradation of habitat, and economic issues. Since its introduction in the 1900s, Cogongrass has spread to most of the counties in Florida. Reproduction occurs through seed production and the creeping rhizome system. This plant is prolific once established with the creation of a very dense rhizome system that retains water and releasing of allelopathic chemicals reducing competition from other plants.
Cogongrass is yellow/green in color with an off-set midrib and a fluffy white seed head. Cogongrass is drought and shade tolerant. Once this grass invades, it will quickly displace the native species and requires frequent and intensive controls.
Early detection is best since a small infestation is easier and cheaper to treat. The larger infestations become more time intensive, expensive, and difficult. There are treatment options for these infestations, make sure that specific instructions are followed and treatment is repeated.
For more information on the biology of this plant and various treatment options visit http://edis.ifas.ufl.edu/wg202. Also, by contacting your local UF/IFAS Extension office for assistance and information.
Cogongrass is a fire-adapted species, thriving where fire is a regular occurrence. In fact, the threat of wildfires greatly increases with the presence of cogongrass, a non-native invasive species. Cogongrass fires burn hotter and faster than native grass fires. This footage, shot in Baldwin County, Alabama, demonstrates how destructive a cogongrass fire can be to native vegetation.
Tawny Crazy Ant (Nylanderia fulva):
Cleaning up large piles of dead ants are a daily cleanup chore for this homeowner. Photo: Dan Culbert, UF/IFAS Extension Okeechobee County
Nylanderia fulva is part of the group of ants called “crazy ants” due to their erratic and quick movements. These ants are medium to small and goldish brown to reddish brown in color. The Tawny Crazy Ants nest in large numbers in leaf litter, soil, rotten logs, under potted plants and along underground electrical conduits.
Nylanderia fulva is a nuisance to humans. They infest gardens, sidewalks and other areas of human traffic. They cause damage to electrical lines. They also displace other native ant species due to their large colony size.
This ant, Nylanderia fulva, has been confused with several other ants such as the Nylanderia pubens and Nylanderia guatemalensis.
Controlling the bug population in your garden and around your home will help decrease the likelihood of Tawny Crazy Ants invading. Avoid transporting plant material, mulches and such to uninfested areas. Granular baits can be used to control smaller populations but large populations will probably need a professional pest control service.
The Tawny Crazy Ant was a Featured Creature by UF/IFAS Entomology and Nematology. Also, the UF/IFAS School IPM has some good information about controlling Tawny Crazy Ant.
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