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 Daniel J. Leonard | Aug 15, 2019
By Evan Anderson, Walton County Agriculture Agent:
Gardening is an attractive pastime, not only for homeowners but also, it seems, for every critter out there that wants a free meal. If a gardener isn’t trying to keep deer, rabbits, or moles out of their crops, they’re fighting against insects of many
Aphids come in many colors, but are a common (and unwelcome) sight on garden plants. Photo courtesy Evan Anderson.
different sorts. With as many different sorts as there are, it can be dizzying to try and keep track of them and to figure out what’s doing damage to which vegetables.
Just because you see an insect in your garden doesn’t mean it’s a bad one. There are many that can be friends to a gardener, patrolling the plants to snack on pests. It’s important to know what you’re looking at before you try to control them; you might end up killing off a helpful bug instead of one that’s a problem!
It can be helpful to look at the damage done by the insects that are plaguing your garden to figure out what kind they are. Piercing / sucking insects drink the fluids from inside plant tissues, and leave small dots or stippling marks, and may exude honeydew, a stick fluid that sometimes grows sooty mold on
Honeybees are an example of a good bug to find in your garden. They help pollinate crops. Photo courtesy Evan Anderson.
it. These bugs include aphids, scales, mealybugs, spider mites, stink bugs, and thrips.
Chewing insects are those that usually go after plant leaves. They chew holes, and if an infestation is bad, they might defoliate a plant very quickly! Caterpillars, grasshoppers, and some beetles are the worst offenders of this sort.
If you need help identifying or figuring out how to control an insect in your garden or any other horticultural topic, feel free to contact your local UF/IFAS Extension office!
An example of damage from piercing/sucking insects. Photo courtesy Evan Anderson.
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 Daniel J. Leonard | May 20, 2019
Spring is a wonderful time of year. After months of dreariness and bare branches, bright, succulent green leaves and flowers of every kind and color have emerged. So too, have emerged gardeners and outdoor enthusiasts ready to tackle all their home and landscape improvement projects planned over the winter. However, this is also the time, when folks first start paying attention to their plants again, that strange, seemingly inexpiable plant problems crop up!
All plant problems can be divided into two categories: biotic problems, or issues caused by a living organism (think insects, fungus, and bacteria), and abiotic problems, issues that arise from things other than biotic pests. It’s the first category that people generally turn to when something goes wrong in their landscape or garden. It’s convenient to blame problems on pests and it’s very satisfying to go to the local home improvement store, buy a bottle of something and spray the problem into submission. But, in many of my consultations with clientele each spring, I find myself having to step back, consider holistically the circumstances causing the issue to arise, scout for pests and diseases, and if I find no evidence of either, encouraging the person to consider the possibility the problem is abiotic and to adopt patience and allow the problem to correct itself. Of course, this is never what anyone wants to hear. We always want a solvable problem with a simple cause and solution. But life isn’t always that easy and sometimes we must accept that we (nor a pest/disease) did anything wrong to cause the issue and, in some cases, that we ourselves actually caused the problem to happen in the first place! To illustrate, let’s consider two case studies from site visits I’ve had this spring.
Cold damage on Boxwood hedge
Three weeks ago, I got a call from a very concerned client. She had gotten her March issue of a popular outdoor magazine in the mail, in which was a feature on an emerging pathogen, Boxwood Blight, a nasty fungus decimating Boxwood populations in states north of us. She had also noticed the Boxwoods in front of her house had recently developed browning of their new spring shoots across most the hedgerow. Having read the article and matching the symptoms she’d noticed to the ones described in the magazine article, she was convinced her shrub was infected with blight and wanted to know if there was a cure. Agreeing that the symptoms sounded similar and wanting to rule out an infection of an extremely serious pathogen, I decided to go take a look. Upon inspection, it was obvious that Boxwood Blight wasn’t to blame. Damage from disease generally isn’t quite as uniform as what I saw. The new growth on top of the hedge was indeed brown but only where the eaves of the house and a nearby tree didn’t provide overhead cover and, to boot, the sides of the hedge were a very normal bright green. Having gone through a recent cold snap that brought several mornings of heavy frost and knowing that the weeks before that the weather had been unseasonably warm, causing many plants to begin growing prematurely, all signs pointed toward an abiotic problem, cold/frost damage that would clear up as soon as the plant put on another flush of growth. The client was delighted to hear she didn’t have a hedge killing problem that would require either adopting a monthly fungicide regime or replacing the hedge with a different species.
Damage to ‘Sunshine’ Ligustrum from pressure washing siding with bleach.
The very next week, another client asked if I would come by her house and take a look at a hedge of ‘Sunshine’ Ligustrum that lines her driveway, whose leaves had “bleached” out, turning from their normal chartreuse to a bronzy white color. This time, having seen similar issues with this particular plant that almost always involved an infestation of Spider or Broad Mites, I figured this was a cut and dry case that would end with a call to her pest control company to come spray the offending bugs. However, though the leaf damage looked similar, I was not able to locate any existing pests or find evidence any had been around recently, rather it appeared the leaves had been exposed to something that “bleached” and burned them. Puzzled, I began asking questions. What kind of maintenance occurs on the plants? Have you fertilized or applied any chemicals recently? Nothing. Then, near the end of our conversation, the client mentioned that her neighbor had pressure washed their house on a windy day and that she was irritated because some of the soap solution had gotten on her car. Bingo. Leaf burn from pressure washing solution chemicals. This time I was guilty of assuming the worst from a pest when the problem quite literally blew in on the wind from next door. Again, the client was relieved to know the plant would recover as soon as a new flush of growth emerged and hid the burned older leaves!
This spring, I’d encourage you to learn from the above situations and the next time you notice an issue on plants in your yard, before you reach for the pesticides, take a step back and think about what the damage looks like, thoroughly inspect the plants for possible insects or disease, and if you don’t find any, consider the possibility that the problem was abiotic in nature! And remember, if you need any assistance with identification of a landscape problem and want research-based recommendations on how to manage the problem, contact your local UF/IFAS Extension office.
