by Gary Knox | Mar 18, 2014
Given crapemyrtle’s reputation for plant vigor and pest resistance, I was shocked to see Chinese crapemyrtles noticeably affected by a previously obscure pest.
Last November I had the privilege of traveling to China with Dave Creech (Stephen F. Austin University), Mengmeng Gu (Texas A&M) and Yan Chen (LSU-Hammond). Crapemyrtles, Lagerstroemia spp., are native to Asia, and China is regarded as the first to cultivate crapemyrtle as a flowering tree. As a crapemyrtle enthusiast, I eagerly looked forward to seeing Lagerstroemia collections in Chinese botanical gardens. What we saw in Beijing surprised us.
![Figure 1 Note the black sooty mold coating the layers of white and grey scale, believed to be crapemyrtle bark scale, Eriococcus lagerstroemiae. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtle-scale-768x1024.jpg)
Figure 1 Note the black sooty mold coating the layers of white and grey scale, believed to be crapemyrtle bark scale, Eriococcus lagerstroemiae. [Photo by Gary Knox in Beijing, China]
Symptoms, Appearance and Distribution in China
An early symptom of crapemyrtle bark scale is black sooty mold covering extensive areas of leaves and stems as a result of honeydew exuded by the scale. Individual scale insects are white to gray in color and ooze pink when crushed (Fig. 2). Large populations build up in branch crotches and extend up branches, appearing crusty white to gray. This scale usually is not present on new growth, leaves or slender stems unless infestations are heavy.
![Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale2-505x1024.jpg)
Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]
We found this scale on crapemyrtle in all four cities we visited, across hardiness zones roughly equivalent to USDA Cold Hardiness Zones 6b to 9 (Beijing, Zone 6b/7a; Nanjing, Zone 8a/8b; Shanghai, Zone 8b/9a; and Kunming, Zone 9). However, this scale was not found on all crapemyrtle. My personal observation is that stressed plants appeared more susceptible to this scale, as exemplified by infestations on freeze-damaged crapemyrtle in Beijing (Fig. 3) or in a poorly maintained planting in the Nanjing Airport parking lot. Our hosts indicated the problem appeared to be more severe on hybrid cultivars introduced from the U.S., and our observations mostly confirmed that.
In the U.S.?
Unfortunately, crapemyrtle bark scale or a similar scale may already be in the U.S. A new scale insect believed to be a species of Eriococcus was first discovered in the Dallas, Texas, area in 2010 where it is problematic on landscape crapemyrtles. It has not been definitively identified by entomologists yet and management recommendations are still being developed. However, this scale has since been observed in Shreveport, LA, Memphis, TN, and Little Rock, AR, undoubtedly being moved with plants. The expanding distribution of this scale and my personal observations of crapemyrtle bark scale throughout China suggest this scale could have a widespread and severe impact on crapemyrtles in landscapes.
![Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale3-767x1024.jpg)
Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]
by Beth Bolles | Mar 12, 2014
Landscapes will soon be transitioning from the dormant phase to actively growing and one of the most beneficial insects of all will be back in action. As soon as flowers open, bees will be visiting to gather pollen and nectar.
This year be a little more observant in the landscape and at your local nursery so that you protect bees during your yard activities. Several insecticides will have new labels that indicate a toxicity to bees and restrictions about applications to blooming plants. Since many landscapes have a wide variety of blooming plants, be very careful not to inadvertently spray when bees are visiting open flowers. Bees are not only killed by a direct spray of certain insecticides, but may carry residual pesticides back to the colony in pollen and nectar.
Since bees and other pollinators are so vital to our food production system, all people who work in landscapes or enjoy gardening as a hobby, need to be a part of bee protection. Read labels, only spray when absolutely necessary, and learn that a little cosmetic damage is worth it in order to protect pollinators.
Some selections of hollies are one of the first landscape shrubs visited by bees in the winter. Learn about the other plants in your yard that are visited by bees so you are better able to protect them.
Holly flowers will soon open.
Photo: Beth Bolles, UF IFAS Escambia County Extension
by Julie McConnell | Feb 18, 2014
Lichen on trunk of oak tree. Image: Julie McConnell, UF/IFAS
Spanish moss and lichen have earned an inaccurate reputation for damaging trees and shrubs in the Florida landscape. Although they may be found in plants that are in decline or showing stress symptoms, they are simply taking advantage of space available to survive. Both plants are epiphytes and are obtaining moisture and nutrients from the atmosphere rather than from the plants they rest upon.
Spanish moss. Image: Julie McConnell, UF/IFAS
Lichen are more commonly found on plants that are in poor health because they need a plant that is growing slowly and access to sunlight. These conditions can typically be found in thin canopies of trees and shrubs under stress. Although they are firmly attached to the surface of the plant, they are not taking nutrients from the tree or shrub, but rather from the air and other sources such as organic debris and bird excrement. If you find lichen on your landscape plants, look further into what stress factors might be causing the plant to grow slowly such as compacted soil, extreme weather conditions, drought stress, disease or insect pressure.
Spanish moss does not harm trees and many people find it an appealing asset to their landscapes. Common misconceptions about Spanish moss include that the weight causes branches to break and that it is a host site for chiggers. Spanish moss is very light and any additional weight is typically insignificant. Although it may harbor some insects and provide nesting material for birds and other wildlife, Spanish moss in trees is not a site conducive to chiggers because they favor low-lying moist environments.
To read more about Spanish moss, lichens, and other common epiphytes please read the EDIS publication “Spanish Moss, Ball Moss, and Lichens – Harmless Epiphytes.”
by Judy Biss | Feb 7, 2014
Photo by Judy Ludlow
The UF/IFAS Panhandle Agriculture Extension Team will once again be offering a Basic Beekeeping School in February and March. These classes will be offered via interactive video conferencing at Extension Offices across the Panhandle. Details are listed below, please call your local UF/IFAS Extension Service to register and if you have any questions. See you there!
- These classes will be taught by Dr. Jamie Ellis and other state and nationally recognized beekeeping experts from the University of Florida Honey Bee Research and Extension Lab and the Florida Department of Agriculture & Consumer Services Bureau of Plant and Apiary Inspection.
- There will be three Monday-evening and one Tuesday evening interactive video conferences from 6:00 – 8:00 pm Central time, (7-9 pm Eastern time) and a Saturday bee-yard field day.
- Each 30-50 minute presentation will be followed by a question/answer period
February 24: Honey Bee Biology and Anatomy
March 3: Varroa Mite Biology and Control
March 10: Honey Bees of the World and Beekeeping History
March 15: Bee-Yard Field-Day – A hands on teaching opportunity
March 18: Yearly Management of the honey bee
- The cost for all five classes is $25 per person or $40 for a family. This fee will cover course materials and refreshments.
- Deadline to register is February 17, 2014. Please contact your local UF IFAS Extension office to register or to find out more details, or click on the following link for a printer-friendly flyer: 2014 Beekeeping in Panhandle
Bay County 850-784-6105
Calhoun County 850-674-8323
Escambia County 850-475-5230
Franklin County 850-653-9337
Gadsden County 850-875-7255
Gulf County 850-639-3200
Holmes County 850-547-1108
Jackson County 850-482-9620
Jefferson County 850-342-0187
Leon County 850-606-5202
Liberty County 850-643-2229
Okaloosa County 850-689-5850
Santa Rosa County 850-623-3868
Wakulla County 850-926-3931
Walton County 850-892-8172
Washington County 850-638-6180
by Larry Williams | Dec 17, 2013
Common symptoms of the black twig borer. Image Credit Matthew Orwat UF IFAS Extension
Q. Small branches are dying in some of my trees. What’s causing this?
A. More than likely the culprit is the Black Twig Borer. This very small beetle, about 1/16 inch long, has been active this year.
Common trees attacked include cedar, golden rain tree, maple, redbud, sweetgum, loquat, dogwood, Shumard oak, Chinese elm, magnolia, Bradford pear and pecan. The beetle is not limited to these trees. And it may attack woody shrubs and grapevines.
Black Twig Borer Entry Holes. Image Credit Matthew Orwat UF IFAS Extension
Black Twig Borer Entry Holes. White Frass Visible. Image Credit Matthew Orwat UF IFAS Extension
This beetle only damages branches that are approximately pencil size in diameter. These small branches die above the point of entrance with the leaves turning brown, creating a flagging effect of numerous dead branches scattered throughout the outer canopy of the tree. These dead twigs with their brown leaves are what bring attention to the infested trees.
Bending an infested twig downward will result in it snapping or breaking at the entrance/exit hole. Carefully putting the twig back together may allow you to see the hole. The hole is usually on the underside of the branch and will be very small, about the size of pencil lead in diameter. Sometimes you may see the minute, shiny black beetle and/or the white brood inside the hollowed out area of the twig at the point where it snapped.
Black Twig Borer inside the stem. Image Credit Matthew Orwat UF IFAS Extension
The black twig borer, Xylosandrus compactus, is one of the few ambrosia beetles that will attack healthy trees. However, the heavy rainfall this summer stressed many of our tree and plant species making them more susceptible to insect damage and disease.Female beetles bore into small branches or twigs of woody plants, excavate tunnels in the wood or pith and produce a brood. Damage occurs when the beetle introduces ambrosia fungi on which the larvae feed. The beetles emerge in late February, attack twigs in March and brood production begins in April. Highest population levels occur from June to September. Adults spend the winter in damaged twigs and branches. So it’s important to pickup and dispose of the small branches as they fall.
Where practical, the best control is to prune tree limbs 3-4 inches below the infested area, then remove and destroy the limbs. Proper mulching, avoiding over fertilization and irrigating during dry weather should improve tree health, allowing trees to better withstand attacks. Chemical controls are usually not practical or effective.
Entry point from a different angle. Image Credit Matthew Orwat UF IFAS Extension
Additional information on this beetle is available though the UF IFAS Extension Office, your County Forester or online at the UF IFAS Featured Creature page
by Alex Bolques | Nov 25, 2013
In search of an entry point into a home: Leaf footed bugs congregating on house siding in search of a warm sheltered environment to spend winter. Courtesy of Bill Stinson
Leaf footed bugs are pests of many seed, fruit, vegetable and nut crops. They get their name from the leaf shape of their back legs. The insect is dark brown to black and about an inch long. Like ladybird beetles, leaf footed bugs can invade your home in the fall in search of a warm sheltered environment to spend winter. In some cases, this may be inside your home. However, unlike ladybird beetles, which can invade a home by the hundreds, leaf footed bugs numbers are considerably less.
In both cases, they enter the home through openings such as cracks, crevices, crawl spaces, attics, ridge vents etc. Once inside, they do not cause any damage, eat, drink or reproduce. Instead, they go into what is called diapause, a dormant state. If you encounter them in living spaces of the home, a common management practice is to collect them by hand or mechanically by removing them with a vacuum cleaner and then releasing them outside. Leaf footed bugs are related to stink bugs and will give off an odor if crushed or held to long in your hand. Once spring arrives, they will become active and you may find them roaming around living spaces again. Use the same control tactic to help them find their way to the outside of the home.
It should be noted that ladybird beetles are considered a beneficial insect that feeds on crop-damaging insects such as aphids, mealy bugs, and white flies. On the other hand, leaf footed bugs are a serious pest of cotton and a direct pest of many seed, fruit, vegetable and nut crops.
Reference
Stink Bugs and Leaf-footed Bugs Are Important Fruit, Nut, Seed and Vegetable Pest
![Figure 1 Note the black sooty mold coating the layers of white and grey scale, believed to be crapemyrtle bark scale, Eriococcus lagerstroemiae. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtle-scale.jpg)
![Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale2.jpg)
![Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale3.jpg)
