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 Evan Anderson | Feb 27, 2020
This time of year, owners of woody plants might notice that leaf canopies are thin. Fruit and ornamental trees, shrubs, and bushes might have shed some leaves over the winter or thinned out due to disease, cold damage, or other problems. When this happens, it can call more attention to the stems of these plants, which may sport a fuzzy, frilly growth on them. More than once I’ve heard people ask, “What is this growing on my plant and how do I stop it from killing it?”.
Red Tipped Lichen – Image Credit Evan Anderson UF / IFAS Extension
Lichen is the fuzzy growth in question, and the good news is that it doesn’t harm the plant it grows on. Lichen is an organism that’s a combination of fungus and either algae or cyanobacteria. The algae photosynthesizes and produces energy to share with the fungus, which provides protection and support. Thankfully, they’re pretty self-contained, and don’t need to steal nutrients or water from whatever they’re growing on. That means they can grow just about anywhere – on rocks, fence posts, tree bark, or on the ground (if you’ve seen deer moss growing in the woods, that’s a lichen!). Again, they are NOT parasitic and do NOT hurt plants.
Lichen on Tree Trunk. Image Credit Evan Anderson, UF / IFAS Extension
It’s common to find lichens growing in many different forms and colors. One alarmed tree-owner brought me a branch decorated with a round blotch that had a bright reddish edge. A Christmas Wreath lichen had found a home on her tree, and while the red rings it forms may look alarming, they’re just as innocuous as other lichens. There may be multiple forms of lichen growing in close proximity on a branch, as well. Flat, wavy, rippled, filamentous, bushy, and powdery looking lichen might all mix together to make a strange (or beautiful) looking collection on a tree.
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 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
by Beth Bolles | Jan 13, 2020
The Southern magnolia (Magnolia grandiflora) has always been a favorite tree since it is associated with my childhood home in Tennessee. I always enjoyed the evergreen leaves and large white flowers. In my parent’s yard, the southern magnolia had branches to the ground that allowed the large leaves to stay hidden in a self- mulching area. I never recall the tree begin called messy because of this growth style.
A Southern Magnolia in a Tennessee winter. Photo by Beth Bolles, UF IFAS Extension Escambia County
Many landscapes today may not have room for a southern magnolia that can grow an average of 60 feet in height with an average spread of 25 feet. Because it’ qualities are still desirable, nursery professionals have developed southern magnolia cultivars that are very popular as landscape features due to different growth habits, leaf sizes, and hardiness to our area’s weather. Although the cultivars will be different from the old favorite southern magnolia in growth form and size, homeowners should still do their homework to make sure trees are located in spots for plants to reach proper height and width growth. Also, like I mentioned for my parent’s tree, many of the new cultivars look best if the lower limbs are not removed.
If you or your landscaper are considering a Southern magnolia cultivar, here are a few details about some you may find available.
‘Little Gem’ dwarf southern magnolia has been the go-to magnolia for new landscapes. The dark green leaves are smaller and the plant will be more compact than the traditional southern magnolia. It is often misplaced in landscapes because of these features. Trees still grow about 25 feet high with a spread of 15 feet.
‘Bracken’s Brown Beauty’ is a very attractive magnolia when given room to grow. Foliage is very attractive with shiny green above and brown on the undersides. This plant can grow 40 to 50 feet in height with a spread averaging 20 feet. Plan not to prune lower limbs to maintain a beautiful form.
Bracken’s Brown Beauty as an accent tree in a lawn area. Photo by Beth Bolles, UF IFAS Extension Escambia County
Bracken’s Brown Beauty flower. Photo by Beth Bolles, UF IFAS Extension Escambia County
‘Southern Charm’ magnolia, registered as Teddy Bear is also a compact plant. It grows upright to about 20 feet with a spread about 15. You still have the beautiful green and brown leaf color along with 6 inch wide flowers.
