by Sheila Dunning | May 25, 2017
As oak trees are now fully leafing out and people start hanging out in the shade of the canopy, many of you are noticing strange growths on the branches. They look like potatoes, spiky cones and fuzz balls on the leaves and stems. Don’t worry. It’s just a harmless wasp that chose that tree to create a nursery for her young.
Galls are abnormal plant growth or swellings comprised of plant tissue. Galls are usually found on foliage or twigs. These unusual deformities are caused by plant growth-regulating chemicals produced by tiny wasps. The chemicals produced by these insects interfere with normal plant cell growth.
The life cycles of the various gall-forming wasps are highly variable. Two or more years are required for gall wasps that develop in woody twig galls to reach maturity. Gall-forming wasps usually overwinter as adults in protected places away from the host tree. As the buds break in the spring and the leaves begin to expand, these small wasps start to lay their eggs in expanding plant tissue. During the egg-laying process or early larval-feeding period, specialized body glands secrete growth-regulating chemicals that interact with certain plant chemicals to produce these abnormal growths.
After a brief period of cell growth, gall development stops completely. Once these galls are formed, they do not continue to use nutrients from the host plant. The insect is confined within “its house” and feeds only on gall tissue during the remainder of its development. The galls provide shelter, protection, and food for the immature wasps. Inside a gall, the larvae are surrounded by tissues rich in nutrients
There are a variety of gall-forming species of small wasps that commonly infest oak, Quercus spp ., trees. Galls generally are aesthetically objectionable to homeowners who find them unattractive and fear that galls will cause damage to the health of their oak trees. Most leaf galls on oak cause little or no harm to the health of a tree. However, twig or branch galls may cause injury by distorting branch development in a heavily infested tree.
Chemical control is seldom suggested for management of leaf galls on oak. Cultural methods of control may be effective in reducing the impact of these insects. Some fallen leaves may harbor various life stages of gall-producing pests. Therefore, it may be useful to collect and destroy all infested leaves. Some of these pests overwinter in twigs and branches of oak. Where such woody galls are detected, prune and destroy the infested plant material when the galls are small and have just started to develop. But, remember every bug needs a home!
All photos by Eileen Buss, UF Entomologist
by Larry Williams | May 11, 2017
Adult Ladybug. Photo Credit: James Castner University of Florida
A number of summers ago, I noticed whiteflies on a confederate rose plant in my landscape. I considered using an insecticide to control the whiteflies but decided against doing so after taking a closer look. What I found was a population of ladybugs – eggs, larvae, pupae and adults.
Ladybug adults and larvae eat whiteflies, as well as other soft-bodied insects such as aphids. So, I waited to see what would happen.
At first I was seeing mostly adult whiteflies, which look like tiny white moths. Adult whiteflies mate and then lay eggs on the underside of leaves. The eggs hatch into flat translucent scale-like nymphs that suck the “juice” from the underside of the leaves.
Eventually, some of the leaves developed a black coating called sooty mold. As certain insects (primarily aphids, some scales and whiteflies) feed, they excrete plant sap that coats the leaves. Sooty mold then grows on this sugary sap. It’s not a pathogen. It just makes the leaves look ugly.
Knowing that the whiteflies would not kill the confederate rose, I was willing to tolerate the sooty mold and allow the ladybug population to build.
Allowing whiteflies to live on your plants may not always be the best option. But in order to have beneficial insects in your landscape, there must be some “bad” insects for them to eat.
Insects such as ladybugs, lacewings and praying mantises eat many pest insects. Encouraging these beneficial insects can allow you to reduce the amount of pesticides applied.
It’s important to learn to recognize the adult and immature stages of these beneficial insects. Ladybugs have larvae that look nothing like
Ladybug larva. Photo credit: Aristizabal University of Florida
the adults. Some ladybug larvae look like small orange and black alligators. Others may resemble mealybugs. Many gardeners that would never kill adult ladybugs mistake their larvae as pests and kill them with insecticides.
The following UF/IFAS Extension website will help you learn to recognize many of our beneficial insects. http://edis.ifas.ufl.edu/topic_beneficial_insects
Once you find beneficial insects in your landscape, reduce or eliminate the use of insecticides. When an insecticide is needed, use environmentally friendly options such as insecticidal soaps, horticultural oils and products that contain Bacillus thuringiensis (Bt).
Sometimes a heavy stream of water from a water hose is all that is needed to remove pest insects from plants and reduce their numbers to an acceptable population.
Remember, leaving a few pest insects is a great way to attract beneficial insects. Tolerating a minor infestation and a little plant damage will benefit the helpful insects, your pocketbook and the environment.
by Sheila Dunning | Mar 20, 2017
Now is the time to prevent your azaleas from being attacked by lace bugs. The azalea lace bug, Stephanitis pyrioides, overwinters as eggs on the underside of infested leaves. Eggs hatch in late March and early April. The insect then passes through five nymphal instars before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult and there are at least four generations per year. Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.
Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed from the underside of the leaf. Lace bug damage to the foliage detracts greatly from the plants’ beauty, reduces the plants’ ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions. The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.
However, lace bugs often go undetected until the infested plants show severe damage sometime into the summer. By then several generations of lace bugs have been weakening the plant. Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.
Adult lace bugs are flattened and rectangular in shape measuring 1/8 to 1/4 inch long. The area behind the head and the wing covers form a broadened, lace-like body covering. The wings are light amber to transparent in color. Lace bugs leave behind spiny black spots of frass (excrement).
Lace bug nymphs are flat and oval in shape with spines projecting from their bodies in all directions. A lace bug nymph goes through five growth stages (instars) before becoming an adult. At each stage the nymph sheds its skin (molts) and these old skins often remain attached to the lower surface of infested leaves.
Azalea lace bug eggs are football-shaped and are transparent to cream-colored. Lace bug eggs are found on the lower leaf surface, usually alongside or inserted into a leaf vein. Adult females secrete a varnish-like substance over the eggs that hardens into a scab-like protective covering.
For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm
by Molly Jameson | Jan 26, 2017
Are you an avid gardener and looking to step it up a notch? Are your gardening eyes bigger than your dinner plate? If you have ever considered selling your bounty for market, you will certainly need to do your homework! One such step you can take is to attend the UF/IFAS Panhandle Extension Team’s So You Want to be a Farmer? Workshop Series.
There’s a lot to know if you want to get into this business! This series aims to introduce new or potential farmers to innovative and environmentally safe production practices, concepts of soil and water management, integrated pest management, how to grow for a farmers’ market, and farm financial management.
Agricultural professionals are actually in high demand. There is an estimated 60,000 highly skilled jobs in agriculture available annually, but only about half of these positions are being filled by graduates in agricultural fields. Additionally, Florida’s farmers are an aging group, and there was an 8% decrease in the number of farms and 26% decrease in acres of cropland from 2002 to 2012.
Fortunately, demand has greatly increased in recent years for locally produced specialty crops, meats, and dairy. There has also been an increase in the number of direct marketing opportunities and small farmers have been able to adopt new technologies, such as season extension techniques and local online marketing, to generate more revenue on small acreages.
The UF/IFAS Extension Panhandle Agriculture Team is hosting the So You Want to be a Farmer? Workshop Series to assist beginning or novice farmers as they navigate the many challenges of getting started.
If you are interested in attending, please register on the So You Want to be a Farmer? Eventbrite page. The cost is $10 per session, with sessions at multiple locations within the east Florida Panhandle.
Please see workshop dates and further details below:
by Beth Bolles | Oct 7, 2016
The year’s mild winter and frequent rain showers have created lush lawns and gardens with an abundance of insects. As a result, we are seeing many predator arthropods taking advantage of the available feast. One of the morning interesting creatures in the garden is the spiny orb weaver spider (Gasteracantha cancriformis) that has an interesting body shape.
Spiny orb weavers are common spiders in landscapes that might not be noticed since they are much smaller than the Yellow garden spider (Argiope aurantia) and the Golden silk spider (Nephila clavipes). Once viewed, the spiny orb weaver will catch your attention because it’s abdomen has six ‘spines’ or points that extend out. Spiders also have a mix of yellow, white, red, or black marking on the abdomen.
Spiny orb weaver in the center of the web waiting for a meal. Photo by Beth Bolles
Although spiders are small, the webs which are common amongst shrubs, trees, and edges of woods become quite substantial in the fall. There may be up to 30 spirals that extend out with the spider situated in the center. You may unexpectedly encounter a web when walking through the garden or mowing around trees and shrubs. There is no worry if a spider accidently gets on you as bites are not common and not considered serious.
Spider working on her web. Photo by Beth Bolles
Some may refer to the spiny orb weaver as a crab spider based on its shape, but it is a web building where the true crab spiders are active hunters often found resting on flowers in order to ambush a meal.
Enjoy our fall weather and look out for this beneficial spider in your landscape.
by Matt Lollar | Sep 29, 2016
Tropical sod webworms (Herpetogramma phaeopteralis) have recently been encountered in a number of yards in the Panhandle. The worms usually feed in large groups and unfortunately, the first, and basically the only, sign of damage is often a large area of shorter grass due to their feeding. The arrival time of sod webworms is also unfortunate because they are part of a group of caterpillars that successively attack turf including fall armyworm (Spodoptera frugiperda), striped grass loopers (Mocisspp.), and the fiery skipper (Hylephila phyleus).
Sod webworm feeding damage in the turf thatch layer. Photo Credit: University of Florida/IFAS Extension.
Description
Larvae
Caterpillars are light yellow to orange with brown spots on each body segment and they have a dark, orange-brown head. They will grow to a full length of slight less than 1/2 inch.
Pupae
The reddish brown pupae are about about 1/4 inch long. The pupae are typically found in the upper thatch layer.
Pupa found in cocoon in St. Augustinegrass thatch. Photo Credit: Steven Arthurs, University of Florida/IFAS
Adults
The moths brown with splotchy wings and are about 3/4 inch wide.
Control
Sod webworms are difficult to control because of their spontaneity. However, in the lawn they hide in the thatch during the heat of the day. Over watering and fertilization can increase the amount of thatch. It is important to follow UF/IFAS guidelines for home lawn management.
The first line of defence is healthy turf. Proper fertilization, irrigation, and mowing height can decrease susceptibility of turfgrass against sod webworm. Over-fertilization is a common cause of caterpillar outbreaks in lawns. Cultural practices such as thatch removal by vertical mowing can help eliminate populations. Eggs are laid on grass blades and removal of grass clippings might also reduce populations.
Numerous chemical control options are available, but softer chemicals such as insecticides containing the bacteria Bacillus thuringiensis are recommended as a first line of defense. Insecticides should be applied in the morning or evening during feeding time. For additional control strategies and basic information please visit the UF/IFAS Sod Webworm Publication.
As oak trees are now fully leafing out and people start hanging out in the shade of the canopy, many of you are noticing strange growths on the branches. They look like potatoes, spiky cones and fuzz balls on the leaves and stems. Don’t worry. It’s just a harmless wasp that chose that tree to create a nursery for her young.
