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 Sheila Dunning | Mar 20, 2020
Until recently, rainfall has been plentiful. That’s great for the water table and preparing plants to wake up for spring. But, insects are also stirring. Bugs are affected by rain in many ways. When water is plentiful, they can grow faster, reproduce sooner and travel farther. Combine that with the fact that the insects’ homes are being flooded out and their normal food sources are displaced; and where do you think they are headed? Yes, into your house. Four bugs you can anticipate seeing after rain events include cockroaches, sowbugs, ants and centipedes.
American Cockroach
Photo by: J.L. Castner
UF/IFAS
Roaches tend to live in places that flood easily, especially this time of year. To survive the cold nights, cockroaches need to find a warm place to rest. Typically those places would be drains, pipes, sewers, along foundations and in crawl spaces. But, when it rains, these locations are often flooded, forcing cockroaches to scurry for their lives to avoid drowning. A crack in weather stripping or window caulking makes a quick hideaway. Once inside, they may decide to stay. Frequent rainy days create the lingering humidity that makes all kinds of places more livable for roaches.
Sowbugs and his cousin, the pillbug, are very small, pill-shaped pests with multiple legs and a series of shell-like plates. Often referred to as roly-polys, these creatures are actually a form of land
Sowbug
Photo by: J.L. Castner UF/IFAS
crustacean related to lobsters, crabs, and crayfish. The sowbug’s breathing tubes require moisture to function properly, so they must stay near water. Typically this fact restricts the sowbug to living in moist soil or sand. Ending up inside a building is normally a terminal condition for them. However, due to the moisture left in the air after a rain event, sowbugs that seek refuge inside are able to survive for longer periods of time. Given the opportunity, sowbugs will reproduce indoors. If they have decaying organic material to feed on, they may stick around even longer; having time to create a multi-generational infestation.
Carpenter Ant
Photo by: J.L.Castner
UF/IFAS
Ants are never too far away. They usually build their colonies in the soil near convenient sources of food and shelter. Being in the ground puts ant colonies at great risk for flooding out, even with short periods of rainfall. When this happens, ants are forces to find higher, drier ground quickly or risk being washed away. What better place than a house? Once inside, the ants get back to work looking for food and building the colony. Expect to see ants around kitchen sinks, on window sills and working their way into cupboards and pantry areas during and after a heavy rain. Unfortunately, if they find all the elements needed to make their home, the ants will be very reluctant to go back outside.
Centipede Photo by: J.L. Castner UF/IFAS
Like the other pests mentioned, centipedes are attracted to humid environments. But, centipedes are active hunting carnivores. They like to feed on roaches, sowbugs and ants. So, they follow them into the house, a well-stocked hunting ground. Centipedes typically only hunt late at night, but in dark areas they can hunt day and night. Finding centipedes if most likely an indication of another pest infestation.
These rain-displaced pests may need some help from a pest control product and/or operator to be discouraged from staying inside. We need the rain. But, keep a close watch for the unwanted visitors.
by Carrie Stevenson | Feb 18, 2020
Several Extension offices in the Panhandle are collecting air potato bulbils for National Invasive Species Week. Photo credit: Esther Mudge, Escambia County
The non-native invasive air potato vine (Discorea bulbifera) has wound its way throughout Florida, from pine forests and creek floodplains to backyards. Their heart-shaped leaves are most noticeable in the spring and fall, where they can take over large areas, not unlike their fellow invasive vine, kudzu. In the fall, the plant produces a potato-like tuber called a bulbil, which grows above ground on the vine. The bulbils drop in the winter and then produce new vines the following spring.
The vine’s growth has been uncontrolled or kept back by herbicide for years, until researchers discovered a biological control insect known as the air potato leaf beetle (Liloceris cheni). In the vine’s native Nepal and China, the beetle controls growth by surviving on the leaves of the air potato, its sole food source. After extensive study, the USDA approved the use of these beetles in Florida to control the air potato vine population here. UF IFAS Extension offices statewide have participated in these beetle release programs, providing thousands of beetles to homeowners and property owners seeking to manage the invasive vine using a chemical-free technique. Left alone, air potato vines can smother full-sized trees, blocking the sunlight and causing them to collapse under the weight of the intertwined vines.
From 2012-2015, beetles were able to reduce air potato vine coverage and bulbil density by 25-70% (depending on location and density of beetle population). The active beetle-production phase of a UF IFAS grant has ended, but researchers are committed to the goal of reducing this nuisance species statewide.
To assist with this process, several Extension offices in the Panhandle are sponsoring a bulbil collection during National Invasive Species Week (NISAW, February 23-29). This effort will serve two important roles: to remove bulbils from the natural environment and to provide a seed source for university researchers seeking to grow air potato vine in a controlled environment, sustaining a continued population of air potato beetles for distribution.
For more information on Air Potato Vines and Leaf Beetles, visit https://bcrcl.ifas.ufl.edu/airpotatobiologicalcontrol.shtml or contact your local County Extension office.
by Larry Williams | Dec 4, 2019
Fire ant control options in some situations include doing nothing.
Fire ant colonies consist of the brood (eggs, larvae and pupae) and adult ants. The adults include winged males, winged females, one or more egg producing queen and workers. The winged males and females mate in spring or early summer after a rainy period. Males die shortly after mating. Newly mated females can fly as far as twelve miles from the nest (or farther carried by wind). After landing, mated females shed their wings and begin digging chambers in which they lay eggs to start a new colony.
A single queen can lay over 2,000 eggs per day! She can live an average of six to seven years. A mature fire ant colony may contain 100,000 to 500,000 workers. Fire ant mounds/colonies can reach densities of 200 to 800 per acre.
You should now begin to understand why fire ants are difficult to control. Where they don’t present a direct threat to human health, the best management practice may be to leave them alone.
Homeowners may have to find a tolerable level. Waging war on this insect can be expensive and requires a long-term commitment. There is no single, universal solution to controlling fire ants. A one-time treatment may make the problem worse. In areas where native ants and fire ants have been reduced or eliminated with insecticides, reinfestation by fire ants into these treated areas is rapid.
A balanced approach to fire ant management is recommended. Those mounds that pose no threat to humans should be left alone. Instead target specific mounds such as those close to buildings and walkways.
When treating single mounds with contact insecticides, it’s critical to treat when the queen and brood are close to the surface, which is between 70ºF to 85ºF. When using fire ant baits, it’s important to apply the bait when the ants are foraging for food. They are most actively doing that between 70ºF to 85ºF. Actively foraging ants will pick up the bait and carry it into the nest within minutes. That’s important because baits tend to quickly go rancid and then are no longer attractive to ants. When using season-long control products, it’s a must to achieve uniform coverage of the area. Always read and follow the label precautions and directions when using any insecticide.
Where fire ants create no threat in out-of-the-way areas on your property, consider the option of leaving them alone.
The following link to a UF/IFAS Extension publication provides options for fire ant control in lawns, gardens and landscapes. http://edis.ifas.ufl.edu/lh059
by Sheila Dunning | Aug 7, 2019
Damage caused by azalea lace bug, Stephanitis pyrioides (Scott), feeding. Photograph by James. L. Castner, University of Florida. Severely damaged leaves become heavily discolored and eventually dry or fall off. Symptoms may sometimes be confused with mite injury, but the presence of black varnish-like excrement, frequently with cast skins attached, suggest lace bug damage (Johnson and Lyon 1991).
You may be noticing the color disappearing from your azaleas right now. Do your azaleas look bleached out from a piercing-sucking insect. The culprit is probably azalea lace bug, Stephanitis pyrioides. This pest overwinters in 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 foliage detracts greatly from the plant’s beauty, reduces the plant’s 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).
Adult azalea lace bug, Stephanitis pyrioides (Scott), and excrement. Photograph by James. L. Castner, University of Florida.
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.
Nymphs of the azalea lace bug, Stephanitis pyrioides (Scott), with several cast skins and excrement. Photograph by James. L. Castner, University of Florida.
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.
Other plant species, such as lantana and sycamore, may have similar symptoms. But, realize that lace bugs are host specific. They feed on their favorite plant and won’t go to another plant species. However, the life cycle is similar. Be sure to clean up all the damaged leaves. That’s where the eggs will remain for the winter. Start next spring egg-free.
For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm
by Larry Williams | Jun 25, 2019
Adult and nymphs of mole crickets. Photo: Julie McConnell, UF/IFAS
The best time to treat for mole crickets is during June through July. But don’t treat at all if mole crickets have not been positively found and identified in the affected lawn areas.
Don’t worry about the adults that are seen flying around lights in the evenings or about the mole crickets found dead in swimming pools this time of year. They are in a mating phase and are doing very little to no damage to lawns during late winter and spring.
We can take advantage of the fact that there’s only one generation per year in North Florida. The eggs will have all hatched by mid to late June. At that time, you’re dealing with young mole crickets that can’t fly and that are much more susceptible to the insecticides designed to kill them. Mole crickets spend winter as adults in the soil. In late February and March, adults emerge and begin mating. Shortly after mating, males die and females fly to suitable areas for egg laying. Mated females deposit eggs in tunnels. After depositing her eggs the female dies. Attempting to control adult mole crickets during this mating period a waste of time, money and product. Plus, adult mole crickets are difficult to control and can easily fly out of treated areas.
You can easily determine if mole crickets are the cause for your lawn problem by flushing them out with a soap and water mixture.
Mix 1½ ounces of a lemon scented liquid dish-washing soap in two gallons of water in a sprinkling can or bucket. Pour the soapy water over an area approximately four square feet and count the number of mole crickets that emerge. It only takes several minutes for mole crickets to crawl to the surface after the soap treatment if they are present. Repeat the process around the yard where you suspect mole cricket problems. If you flush an average of two to four crickets are flushed out per site, control may be needed.
There are a number of insecticides on the market to control mole crickets. But before using any product, first identify the problem as mole cricket damage by using the soap flush technique. Then choose a lawn insecticide that lists mole crickets on its label. And finally read the label carefully for use directions, application techniques, irrigation requirements and precautions.
For more information on mole crickets, including recommended insecticides and other non-chemical control options, contact the UF/IFAS Extension Office in your County or access the following links.
Insect Pest Management on Turfgrass
Shortwinged Molecricket
Mole Cricket IPM Guide for Florida
