by Beth Bolles | Jan 13, 2015
The Chinese privet, Ligustrum sinense, is a plant that is well known to many people as a great nuisance in the landscape. It is also a Florida noxious weed because of its invasive nature.
Originally grown as an ornamental that formed a hedge and tolerated poor conditions, the Chinese privet has now spread to natural areas and grows easily on disturbed soils. Plants are full of white fragrant flowers in the spring with abundant small black fruit forming late summer and remaining into the winter. Seeds are easily spread by wildlife to new areas but new plants can also grow from roots.
Privet may be best identified when it is in bloom.
Chinese privet easily forms a thicket, shading areas and impacting the growth of native plants. Homeowners can identify any plants growing on their property and work to manage Chinese privet when plants are not in seed. If you need assistance in identification, contact your local Extension office or view pictures online.
Even though homeowners will not find Ligustrum sinense in the nursery, cultivars of this plant may be found. One newer selection is ‘Sunshine’. This is a reportedly sterile cultivar that grows much smaller and has yellow foliage. Homeowners who choose to install ‘Sunshine’ may still need to be cautious since there has not been extensive research in Florida to verify that it will not become a future issue.
by Alex Bolques | Jun 17, 2014
Homeowner accounts of white fluffy woolly masses on woody ornamentals have been on the rise. They can appear on the ends of a wide variety of woody ornamental branches in the landscape. A closer inspection of these white woolly masses can provide the curious observer with a startling surprise. “It’s Alive!” It moves and seems to jump at you, most likely jumping away from you. Once you have recovered from the mildly frightful encounter, you ask yourself, “What was that?”
Adult citrus flatid planthopper, Metcalfa pruinosa
(Say). Credits: Photograph by: Lyle J. Buss, University of Florida
They are planthoppers (Metcalfa pruinosa), an insect in the order Hemiptera. The common name for this woolly looking planthopper is the citrus flatid planthopper (CFP). As the name implies, they occur on citrus but can also be found on many woody ornamentals and fruit trees. The adult planthopper wing arrangement is tent-like, meaning that the forewings are held over the insect abdomen in a tent configuration.
Nymph of the citrus flatid planthopper, Metcalfa
pruinosa (Say). Credits: Photograph by: Lyle J. Buss,
University of Florida
The nymph, young immature insect, produces the white woolly material that is characteristic of CFP. At first sight, they can be mistaken for mealy bugs, which may look similar since they are covered with cottony white filaments. They can also be mistaken for cottony cushion scale.
Mealybugs. Credits: James Castner, University
of Florida
Cottony cushion scales, Icerya purchasi, on twig.
Credits: James Castner, University of Florida
In both of these cases of mistaken identities, the insect will not jump or hop around. No chemical control is necessary although sooty mold can occur on heavily populated plants. In that case, a soapy water treatment can be applied.
Follow these links to more information on the citrus flatid planthopper, mealy bugs, and cottony-cushion scale.
by Larry Williams | Jun 3, 2014
Glistening webbing formed by tree cattle (psocids) Photo credit: Doug Caldwell, University of Florida
Many people are noticing small insects on trunks and branches of their trees. When disturbed, these insects move in a group and are commonly called tree cattle because of this herding habit. They are ¼ inch brownish-black insects with white markings.
Some people assume that these insects will injure their trees but they are harmless. They could be considered beneficial.
These insects are called psocids (pronounced so-cids). They have numerous common names including tree cattle and bark lice. They feed on lichen, moss, algae, fungi, spores, pollen and the remains of other insects found on the tree’s bark. As a result, they are sometimes referred to as bark cleaners.
Tree cattle may form webbing. This webbing is tight against the tree’s trunk and/or limbs. It appears suddenly. The webbing is used as a protection from weather and predators. Underneath you may find psocids.
The glistening webbing may attract a person’s attention resulting in the tree being visually inspected from top to bottom. A dead branch or other imperfections in the tree may be noticed and then wrongly blamed on the tree cattle. I’ve talked to homeowners that sprayed their trees with insecticides or that hired pest control businesses to treat the trees as a result of finding the webbing/psocids. One person told me that he cut down a tree after finding tree cattle. He wrongly assumed that these insects were pests that might move through the area and kill trees. He thought he was doing a good thing.
Adult female psocids lay eggs in clusters on leaves, branches and tree trunks. After hatching, the immature insects (nymphs) remain together under their silk webbing. Adults have wings which are held roof-like over their body. Nymphs are wingless. Psocids usually have several generations per year in Florida.
After seeing the webbing and/or insects, many people insist on spraying insecticides because they believe these insec
Under the webbing live hundreds of psocids. Photo credit: UF/IFAS Jim Castner
ts are damaging their trees. But as mentioned, they are bark cleaners and do not damage trees. If the silk webbing is considered unsightly, a heavy stream of water from a garden hose can be used to wash insects and webbing off infested trees. If nothing is done, the webbing usually goes away in several weeks.
Psocids can be found on many rough-barked hardwood trees and palms. Occasionally, they may be found on wood siding, fence posts or similar areas.
by Eddie Powell | Jun 3, 2014
During this growing season monitor your plants and keep them healthy as a healthy plant will be able to better survive an invader attack.
Nematode populations can be reduced temporarily by soil solarization. It is a technique that uses the sun’s heat to kill the soil-borne pests. Adding organic matter to the soil will help reduce nematode populations as well. Nematodes are microscopic worms that attack vegetable roots and reduce growth and yield. The organic matter will also improve water holding capacity and increase nutrient content.
Tomato Spotted Wilt Virus
Credits: UF/IFAS
If you choose to use pesticides, please follow pesticide label directions carefully. Learn to properly identify garden pests and use chemicals only when a serious pest problem exists. If you have questions please call your UF/IFAS county extension office. We can provide helpful information about insect identification.
Organic gardeners can use certain products like BT(Dipel) to control pests. Please remember not every off-the-shelf pesticide can be used on every crop. So be sure the vegetable you want to treat is on the label before purchasing the product.
Follow label directions for measuring, mixing and pay attention to any pre-harvest interval warning. That is the time that must elapse between application of the pesticide and harvest. For example, broccoli sprayed with carbaryl (Sevin) should not be harvested for two weeks.
Spray the plant thoroughly, covering both the upper and lower leaf surfaces. Do not apply pesticides on windy days. Follow all safety precautions on the label, keep others and pets out of the area until sprays have dried. Apply insecticides late in the afternoon or in the early evening when bees and other pollinators are less active. Products like malathion, carbaryl and pyrethroids are especially harmful to bees.
To reduce spray burn, make sure the plants are not under moisture stress. Water if necessary and let leaves dry before spraying. Avoid using soaps and oils when the weather is very hot, because this can cause leaf burn.
Control slugs with products containing iron phosphate.
Cucumber Mosaic Virus
Credits: UF/IFAS
Many common diseases can be controlled with sprays like chlorothalonil, maneb, or mancozeb fungicide. Powdery mildews can be controlled with triadimefon, myclobutanil, sulfur, or horticultural oils. Rust can be controlled with sulfur, propiconazole, ortebuconazole. Sprays are generally more effective than dusts.
by Mary Salinas | Nov 4, 2013
For centuries, people annoyed with plant pests have used oils to control insects, mites, and even some fungal diseases. Current oil products are better than ever!
Sample oil products for pest control. Photo by Mary Derrick.
Commercially available horticultural oils are mineral oils from refined petroleum products. Impurities are removed and then an emulsifying agent is added that allows the oil to mix with water for application. Neem oil is a newer product that has become increasingly popular; the oil is an extract of the seeds of the neem tree.
What are some of the advantages of using an oil for pest control?
- Oils are inexpensive and easy to apply
- Oils can be used on most plants (check the label for a list!)
- Oils control a wide range of pests that feed on plants (again, check the label for a list of pests the product will control!)
- Oils pose a low risk to people, pets, and desirable beneficial predators
- Since oils kill pests by blocking their breathing holes (spiracles) and/or gumming up their mouthparts, there is no chance for resistance to develop
- One product can control both insects and some diseases like powdery mildew at once
- Oils can be combined with some other pesticides to provide greater control
[warning] Don’t combine with, or use within 30 days of, any sulfur based pesticide. The combination can harm your plants![/warning]
There are always drawbacks to a product. What are the drawbacks?
- Some plants (including cryptomeria, junipers, cedars, maples, and redbud) are damaged by oils – check the label!
- Ensure good coverage during spraying as pests must be contacted with the oil in order for the control to work
- Oils break down quickly and reapplication may be necessary
- Check the label for instructions on the temperature range when it can be used. Older formulations generally are safe when temperatures are in the 40 to 80°F range but ultra-fine oils can generally be safely applied during hotter weather.
For further information:
Natural Products for Insect Pest Management from UF IFAS Extension
Insect Control: Horticultural Oils from Colorado State University Extension
Less Toxic Pesticides from Clemson University Cooperative Extension
