by Ray Bodrey | Apr 8, 2020
Spring has arrived and so have the insects. Caterpillars are crawling around and one possesses a unique appetite.
Neodiprion spp. is the most common defoliating insect group affecting pine trees. In all, there are 35 species that are native to the U.S. and Canada. The redheaded pine sawfly, Neodiprion lecontei, is the primary species found in the Florida Panhandle.
Adult sawflies can be as large as 1/3 of an inch in length. The female can be two-thirds larger than the male and are mostly black with a reddish-brown head, with occasional white coloration on the sides of the abdomen.
Mature larvae of the redheaded pine sawfly. Credit: Patty Dunlap, Gulf County Master Gardener.
The ovipositor, the tube-like organ used for laying eggs, is saw-like, hence the common name. During the fall, females make slits in pine needles and deposit individual eggs, up to 120 eggs at a time. The eggs are shiny, translucent and white-hued. Mature larvae (caterpillars), as seen in the accompanying photo, are yellow-green, emerge in the spring and feast on pine needles. After weeks of feeding on needles, the mature larvae drop to the ground. The cocoon, a reddish-brown, thin walled cylinder, is spun in the upper layer of the soil horizon or in the leaf litter; this is called the pupae stage. The pupae overwinter, and adults emerge from the cocoon in the spring of the following year.
Mature larvae are attracted to young, open growing pine stands. Pine is the preferred host, but cedar and fir, where native, are secondary food sources. Neodiprion lecontei is an important defoliator of commercially grown pine, as the preferred feeding conditions for sawfly larvae are enhanced in monocultures of shortleaf, loblolly, and slash pine, all of which are commonly cultivated in the southern United States. Defoliation can kill or slow the growth of pine trees as well as predispose trees to other insects or disease.
Are there control methods? Yes, biological control is a major factor, as natural enemies are numerous. Disease, viruses and predators help regulate population control. For small scale control, physically removing eggs or larvae is key. Again, most infestations occur on younger tree plantings, so they’ll be in reach. Be sure to scout young pines for signs of infestation. Horticultural soaps and oils are effective chemical controls, if needed.
For more information, contact your local county extension office.
Supporting information for this article can be found in the UF/IFAS Extension EDIS publication, “Redheaded Pine Sawfly Neodiprion lecontei” by Sara DeBerry: https://edis.ifas.ufl.edu/pdffiles/IN/IN88200.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
by Matt Lollar | Mar 20, 2020
It’s always fun to add new plant to the landscape. And it’s even more fun to propagate your own plant material. The question is, what plant propagation method is best? The answer depends on a number of factors such as:
- How much time and money is available?
- Is a uniform crop desired or is trait variation preferred?
- What is the plant species being propagated?
Plants can be propagated either by seed (sexual propagation) or by segments of vegetative material (asexual propagation). Sexual propagation takes far less time and effort because new plants are being started from the seeds (offspring) of parent plants. This type of propagation promotes genetic diversity because offspring may not have the exact characteristics of the parent plants. Sexual propagation increases the possibility of hybrid vigor, which is the improved quality of plant material to that of parent plants. Asexual propagation usually takes more time, but generally ensures that propagated plants will maintain the same characteristics as the parent plant. For some species it may be the only way to pass on desired traits to subsequent generations and it may be the only way to propagate certain species. A plant produced vegetatively can become larger than a plant produced by see in the same amount of time.
Tips for Successful Sexual Propagation
- Seed Collection – Seeds should be collected when fruit is ripe, just before they fall to the ground. In general, seeds should be cleaned, dried, and stored at 40 degrees Fahrenheit (in a refrigerator). However, palm seeds should be planted immediately after harvesting and cleaning.
- Seed Dormancy – Some seeds have thick seed coats the inhibit germination. Some seeds need to be scarified (breaking of the seed coat) and/or stratified (stored in a specific environment) in order to germinate.
- Seed Sowing – Seeds can be germinated in flats or other suitable containers in a seed starting media. Seeds should be planted at a depth of two to three times their diameter, but no deeper than 3 inches. Cycad seeds should be planted just below the medium surface.
Seeds stored in an envelope. Photo Credit: University of Florida/IFAS
Tips for Successful Asexual Propagation – In general, asexual propagation is the propagation of plant material from cuttings of stems, leaves, and/or roots.
- Rooting Hormones – Increase rooting percentage, hasten root initiation, increase the number of roots per cutting, and increase root uniformity. Auxin based rooting hormones (Indolebutyric acid (IBA) and Naphthalenacetic acid (NAA)) are available in dry or liquid forms. It is important to use the correct concentration for the particular plant species because over application can cause damage to cutting base.
- Sticking Cuttings – Cuttings should be stuck in the medium only deep enough to support the cuttings and hold them upright (1/2″ to 1″ deep).
- Post-Rooting Care – Fertilization should be applied as soon as roots emerge from the cuttings. However, overfetilization can increase soluble salts and burn roots.
Examples of Asexual Propagation
- Softwood Cuttings – Taken from woody plants usually three to four weeks after a new flush of growth. Commonly propagated species using this method include: crape myrtle; magnolia; oleander; azalea; jasmine; and boxwood.
- Semihardwood Cuttings – Similar to softwood cuttings, but the lower portion of the cutting has become lignified (woody). Usually taken from new shoots six to nine weeks after a flush of growth. Commonly propagated species using this method include: camellia; pittosporum; junipers; and some hollies.
- Hardwood Cuttings – Taken from the previous season’s growth, just before or during the dormant period. Commonly propagated species using this method include narrow-leaved evergreens and deciduous species during the dormant season after leaves have dropped.
- Leaf Cuttings – Comprised of only the leaf blade or the leaf blade and petiole (leaf stalk). Cuttings are stuck upright in the propagation medium with the basal end (petiole end) of the leaf inserted into the propagation medium. Commonly propagated species using this method include begonias and peperomias.
- Root Cuttings – Taken in late winter or early spring from two to three-year-old plant material. Plants propagated by root cuttings may not reproduce true to type if they are budded or grafted. Commonly propagated species using this method include: plumbago; bayberry; oakleaf hydrangea; and yucca.
Plants being propagated by leaf cuttings. Photo Credit: University of Florida/IFAS
This article provides only a brief overview of propagation methods and techniques. For more information on plant propagation please visit University of Florida Plant Propagation Glossary or Plant Propagation Techniques for the Florida Gardener. Please be advised that some plant material is patented and it is illegal to propagate patented material without written authorization or licensing of the patent holder. If it is patented, a notation of patent number will be on the tag.
by Mary Salinas | Feb 18, 2020
Florida is home to some amazing and gorgeous plants that are underused and underappreciated in the home landscape. One such plant is an evergreen and easy-care large shrub or small tree known as black titi or buckwheat tree, botanically known as Cliftonia monophylla.
Pink-flowered variety of black titi, Cliftonia monophylla. Photo credit: Mary Salinas, UF/IFAS Extension.
Black titi or buckwheat tree. Photo credit: Chris Evans, University of Illinois, bugwood.com
Black titi is commonly found in wet areas and at the edges of swamps in USDA hardiness zones 7B through 9A from Louisiana through the Florida panhandle and into South Carolina. This is a perfect plant for those areas of your landscape that are low and consistently moist.
Early spring brings clusters of small white flowers at the tips of the branches. Occasionally one can find the pink-flowered variety of black titi in the native nursery trade. These fragrant flowers provide an early season nectar source for bees in February and March. The flowers give way to golden-amber seed pods that resemble buckwheat. The seed pods turn a pleasing orange-brown and persist on the plant through winter. The shiny dark green evergreen leaves along with the seed pods provide an additional ornamental quality to the tree in fall and early winter.
Black Titi golden-amber fruit. John Ruter, University of Georgia, bugwood.org
For more information:
Florida Honey Bee Plants
USDA Plant Database
Florida Native Plant Society
by Danielle S. Williams | Jan 23, 2020
Resurrection Fern on Pecan Tree. Image Credit Danielle Sprague, UF/ IFAS Extension
This week, I received a call about identifying a plant growing on a pecan tree in someone’s yard. With the recent rain we’ve experienced after a rather dry period, I had a pretty good feeling it was a resurrection fern. A quick picture sent in to me by the homeowner confirmed this.
Resurrection fern, Pleopeltis polypodioides is a native fern found in many hardwood trees throughout the southeast. In our area, it is found most often on the branches and trunks of live oak and pecan trees. The resurrection fern gets its name from its ability to withstand extensive periods of drought by shriveling up and appearing dead. When it is exposed to water again, it will ‘come back to life’, uncurling its fronds and appearing bright green.
This creeping fern has a long, skinny stem to which the fronds or leaves are attached. The stem is less than 1/12″ in diameter and fronds are anywhere from 4 to 12 inches long. Unlike other plants, resurrection fern reproduces by spores, not seeds. These spores can be found on the underside of the fronds in clusters known as sori. The sori look like brown to black scales.
Resurrection Fern before and after, Image courtesy IFAS Gardening Solutions
Resurrection fern is a perennial epiphyte or ‘air plant’, meaning that it attaches itself to other plants, but it does not steal water or nutrients from its host plant. Instead, it absorbs water and nutrients that collect on the outer surface of the bark. One of the questions posed by the homeowner was the need to control the resurrection fern, however, since it is an air plant and does not harm the tree, there are no chemicals recommended to control it.
In 1997, the resurrection fern made its first debut in outer space! Because of its unique attributes, the National Aeronautics and Space Administration (NASA) launched into space for an experiment to study the ‘resurrection’ in zero gravity. Amazingly enough, they found that the resurrection fern was able to rehydrate and recover in zero gravity!
For more information on resurrection ferns:
UF/IFAS Gardening Solutions: Resurrection Ferns
Island Ecology: Resurrection Ferns
by Carrie Stevenson | Jan 22, 2020
Master Gardeners demonstrate correct tree planting techniques.
Last week, we celebrated Florida’s Arbor Day. “What?” you may say—“Isn’t Arbor Day in the spring?” Well, yes and no. National Arbor Day is celebrated in the spring (April 24 this year), usually within a day or two of Earth Day. However, because of the wide range of climatic environments throughout the United States, each state has its own date based on ideal growing conditions. As it stands, Florida’s is the 3rd Friday in January, as we are situated so very far south. Alabama and Georgia, where so many of us north Floridians experience similar weather, hold their Arbor Days in late February.
Contrary to popular opinion, the optimal planting time for trees is not in the spring, but in fall and winter. Planting during dormancy allows trees to focus their energy resources on growing healthy roots. In the coming spring, a steady supply of warmth, sunshine, and pollinators will bring on leaf growth, flowers, and fruit.
Check with your local Extension offices, garden clubs, and municipalities to find out if there is an Arbor Day event near you! Several local agencies have joined forces to organize tree giveaway events and sales in observance of Florida’s Arbor Day.
Saturday, January 25th
Leon County: UF/IFAS Extension Leon County Master Gardeners will assist with the county’s Arbor Day tree planting at 9 a.m. Martha Wellman Park, 5317 W. Tennessee St., Tallahassee.
by Matt Lollar | Jan 13, 2020
Scale insects on a cabbage palm (Sabal palmetto). Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
This week I was on a couple site visits to look on some cabbage palms (Sabal palmetto) and some banana shrubs (Michelia figo). The palms had a white, waxy substance on their frond petioles and the banana shrubs had white specs on the tops of their leaves. Upon further investigation, I realized the waxy substance and specs were both different species of scales. Scale insects are serious pests of a number of ornamental plants. Here in Florida there are 13 different families of scales with the most common being armored scales, soft scales, and mealybugs. Scales have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Heavy infestations cause extensive leaf yellowing, premature leaf drop, branch dieback, and eventually plant death.
Scale Biology
The life cycle of a scale begins with eggs being laid beneath wax coverings or beneath the adult female. Eggs typically hatch in 1 to 3 weeks. The newly hatched nymphs, called crawlers, move around a plant until they find a spot to feed. Once a feeding site is located, their piercing sucking mouthparts are inserted into the plant and the crawlers begin to feed and grow. The males of many scale species develop wings as adults and fly to other plants to reproduce.
Magnolia white scales on a banana shrub (Michelia figo). Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Armored Scales
Armored scales get their armor by secreting a waxy covering over their bodies that is not attached. The scale lives under this covering and uses it as a protection to feed under. Armored scales can be almost any color or shape and range anywhere from 1/16 to 1/8 inch in diameter. For females, these shapes range from circular to oval to long and slender. The males typically have coverings that are more elongate and smaller than the females. As adults, the males are tiny, winged, gnat-like insects and are rarely seen.
Gloomy scale (Melanaspis tenebricosa) with armored covering removed. Photo Credit: A. G. Dale, University of Florida/IFAS
Soft Scales
Similar to armored scales, soft scales secrete a waxy covering, but it is attached to their bodies. Soft scales can be a number of colors, shapes, and sizes and range anywhere from 1/8 to 1/2 inch in diameter. Their shapes vary from spherical to nearly flat.
Population of adult and immature tuttle mealybugs (Brevennia rehi) on a blade of zoysiagrass. Photo Credit: Lyle J. Buss, University of Florida/IFAS
Mealybugs
Mealybugs are soft-bodied insects that possess a covering of flocculent, white, waxy filaments. They are about 1/8 inch in length and usually pinkish or yellowish in color. Mealybugs have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Mealybug damage produces discolored, wilted, and deformed leaves.
Scale and Mealybug Management
- Cultural Control – Plant inspection prior to purchase or installation is the first line of defense against a scale or mealybug population. Make sure to inspect the undersides of leaves and plant stems. Infested sections of plants can be pruned and plant material should be cleaned from the planting area and discarded. Also, you can increase air flow and decrease humidity by proper installation and pruning. Over-fertilizing can also increase pest populations.
Larva of a brown lacewing. Credits: Lyle Buss, University of Florida.
- Biological Control – Predators, such as ladybugs and green lacewings, are usually present in large enough numbers to suppress scales and mealybugs to a desirable threshold. However, broad-spectrum insecticides and bad weather can reduce predator numbers. Look for signs of predation by inspecting dead scales for jagged holes in their waxy coatings. If predation signs are present, use more selective chemical controls and oils as opposed to broad-spectrum products.
- Chemical Control – Timing is everything when it comes to managing scale and mealybug insects. Crawler activity is more pronounced with the flush of new plant growth in the spring. Before application, prune infested plant parts off first to promote greater penetration of insecticides into the foliage. Dormant Oils are often used in the winter to smother scale insects. These are good choices to implement because they don’t harm non-target or beneficial insects. Care must be taken to read the label and use them at the correct temperature, since use in hot weather may burn foliage. Contact products (acephate, bifenthrin, carbaryl, etc.) must be applied to inhibit the crawler stages of these insects and systemic products (acetamiprid, imidacloprid, thiamethoxam, etc.) can be used on the sessile growth stage. Plants should be sprayed thoroughly to the point of drip or “run off” from leaves, twigs, and stems. Repeated applications may still be necessary even if the timing is right, as crawler populations are often large and crawlers like to hide under old waxy scales. Systemic drenches are also a viable option. With good spray coverage, horticultural oils can kill scales at all stages of growth. Refer to the product label for phytotoxicity and temperature guidelines. Even after successful treatment, the outer coatings of the scales may remain on the plant material for weeks, which can be unsightly. The best way to determine if scales are dead is to squeeze them. They will be dry when squeezed if they are dead and they will ooze liquids if they are living (they were at least alive to the point of being squashed).
For insect identification and additional information on scale control, please see:
A Guide to Scale Insect Identification
UF/IFAS Featured Creatures
Your County Extension Office
