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For One Insect, Pine Needles are the Preferred Menu Item

For One Insect, Pine Needles are the Preferred Menu Item

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.

A Few Simple Steps to Stop Blossom End Rot Before it Begins!

A Few Simple Steps to Stop Blossom End Rot Before it Begins!

There aren’t many more frustrating things than growing seemingly healthy tomatoes, those plants setting an abundance of flower and fruit, and then, once your tomatoes get about the size of a golf ball, having the fruit rot away from the base. This very common condition, called Blossom End Rot (BER), is caused one of two ways: by either a soil calcium deficiency or disruption of soil calcium uptake by the plant.  Fortunately, preventing BER from occurring and then realizing an awesome crop of tasty tomato fruit is relatively simple and home gardeners have a couple of possible preventative solution!

Blossom End Rot damage. Photo Courtesy Larry Williams, Okaloosa County Extension.

  1. Soil Test & Lime if Needed. The only way to really know if your soil calcium level is sufficient is through a soil test.  A complete soil test through the UF Soil Lab or other lab measures both raw nutrient levels and pH.  Testing for pH is especially critical.  For calcium, either already in the soil or in a supplement you apply, to be available to tomato plants, soil pH needs to be between 6.0-7.  In more “acidic” soil pH below 6, nutrients like iron and aluminum become more available to your tomato plants, outcompeting calcium for uptake into the roots. We don’t want that. If your soil test indicates a pH below 6, it will give a lime recommendation somewhere between 3-5 lbs/100 ft sq of garden area to raise the pH to the sweet spot between 6.0-7.0 where your tomatoes will thrive.
  2. Use a Non-Lime Calcium Supplement. If you’ve had your soil tested and your pH is fine, adding more lime as a calcium supplement isn’t helpful.  Using lime as an additional calcium source can actually lift pH above that 6.0-7.0 zone and cause other problems.  At this point, once pH is where we want it, I like to add a non-lime calcium supplement.  There are lots of options here.  Traditional fertilizers labeled for tomatoes and veggies tend to have a good calcium content in the 6-10% range and work great.  However, if you’re into organic gardening or just don’t need the extra nutrient value of a complete fertilizer, Gypsum is a good calcium supplement and is widely available.  Regardless of which non-lime source you choose, apply at planting or shortly after and follow label rates for best results.
  3. Water Properly. Consistent watering is key in helping ward off BER. Though we know BER is generally

    Healthy ‘Big Beef’ tomatoes grown in 2019 with a pH of 6.5, amended with Gypsum at planting, and watered regularly each day! Notice no BER. Photo courtesy the author.

    caused by calcium deficiency, it can be induced by creation of distinct wet and dry periods from non-regular watering, interfering with calcium uptake and availability to the plant.  So, while you may have adequate soil calcium, if you don’t water correctly, the condition will happen anyway!  It’s also good to keep in mind that mature tomato plants use large quantities of water daily, so during the heat of summer, plants in containers may need to be watered multiple times daily to maintain consistently moist soil.  Think about it, you don’t drink 8 glasses of water when you wake up and then never drink again throughout a hot day.  A tomato is no different.  Allowing your plants to wilt down before providing additional water ruins productivity and can induce BER.

Blossom End Rot, while one of the more destructive fates of tomatoes, is totally preventable by a little legwork early in the growing game from you!  Soil test and change pH with lime if needed, add a shot of calcium through a tomato blend fertilizer or non-lime supplement like gypsum, and water regularly!  Do these three things and you’ll be well on your way to a great crop of early summer tomatoes.  If you have any questions about tomato blossom end rot or any other horticulture or agricultural topic, please don’t hesitate to reach out to us at the UF/IFAS Calhoun County Extension Office.  Take advantage of this beautiful spring weather and get in the garden today!  Happy gardening.

Cutworms, the Moonlit Garden Vandals

Cutworms, the Moonlit Garden Vandals

Larva of the granulate cutworm (Feltia subterranea). Photo by John L. Capinera, Entomology and Nematology Department, University of Florida.

Larva of the granulate cutworm (Feltia subterranea). Photo by John L. Capinera, Entomology and Nematology Department, University of Florida.

 

One of the biggest predicaments growing vegetables in my backyard garden is dealing with cutworms. Cutworms are a type of nocturnal moth larvae that feed by wrapping themselves around seedling stems at the soil surface. They then cut the stem of the seedling in two – as if Edward Scissorhands dropped by for a visit – killing the plant. There are multiple species, but one of the most common in Florida is the granulate cutworm (Feltia subterranea). They are distributed most frequently in the tropics but can occur as far north as Southern Canada and regularly occur in the Southeastern United States.

My plan was to install cutworm collars the next morning. But that night, cutworms chewed through the stem of this tomato seedling in two locations. Photo by Molly Jameson.

My plan was to install cutworm collars the next morning. But that night, cutworms chewed through the stem of this tomato seedling in two locations. Photo by Molly Jameson.

Since cutworms feed at nighttime it is particularly frustrating, as you will find plants which appeared fine in the evening destroyed by morning. What’s even more frustrating is they feed in multiple seasons on a very wide range of crops, including tomatoes, beans, corn, eggplant, lettuce, peppers, watermelon, celery, broccoli, cabbage, and kale, to name a few. This fall and winter, I even found they had attacked my carrots and onions, which I thought would be more resistant.

One approach a backyard gardener can take in combatting cutworms is to use physical barriers. Netting or row cover can help prevent mature moths from ovipositing their eggs. But if you already have larvae invading, this technique will be ineffective.

For plants with stems less than pencil-width thick, make cutworm collars to help protect young seedlings from attack. Photo by Molly Jameson.

For plants with stems less than pencil-width thick, make cutworm collars to help protect young seedlings from attack. Photo by Molly Jameson.

Plants with stems that are less than pencil-width thick are most susceptible to cutworm damage. A useful tactic is to make what are called “cutworm collars.” Surround individual seedlings with toilet paper rolls, taking care not to break fragile stems as you position the rolls over the plants. Materials such as soda cans or cereal boxes can be cut into strips to encircle seedlings if toilet paper rolls are too small to safely fit over the plant. Try to extend the cardboard two inches below and two inches above the soil surface. In this way, the cardboard acts as a barrier, and can help keep cutworms from accessing the stems.

Unfortunately, if cutworms are already hiding in soil close to the plants, the collars might not be effective. Another technique to try, especially if cutworms are already present, is the toothpick method. Place two toothpicks vertically in the soil on each side of the stem. They should be right up against the stem. In this manner, the toothpicks should prevent the cutworm from wrapping around the stem to chew through.

This onion start was given a moonlit haircut by feasting cutworms. If you are lucky, you may be able to find the culprit by digging around the soil adjacent to the afflicted plant. Photo by Molly Jameson.

This onion start was given a moonlit haircut by feasting cutworms. If you are lucky, you may be able to find the culprit by digging around the soil adjacent to the afflicted plant. Photo by Molly Jameson.

It can also be helpful to scout your garden for cutworms. Carefully dig one to two inches into the soil near afflicted seedlings. The caterpillars are small, growing from a few millimeters up to less than two inches in length, but tend to stay curled up near the soil surface within about a foot radius of their vegetative victims. Crush any cutworms you find, or for the squeamish, simply drop the cutworms into soapy water.

Applying the bacterial insecticide Bacillus thuringiensis var. kurstaki (Bt for short) may help control cutworms but be sure to apply in the evenings and not before a rainfall or irrigation event, as sunlight and water render Bt useless. And keep in mind, cutworms must digest Bt to be effective, so you may need to apply multiple applications. As with any insecticide, always remember to follow the directions on the label. Once seedling stems grow larger than pencil-width, they should be safe from cutworm mayhem. That is… until the next garden vandal comes along!

To learn more, visit the University of Florida Entomology and Nematology Department’s Featured Creatures page about the granulate cutworm (http://entnemdept.ufl.edu/creatures/veg/granulate_cutworm.htm). You can also search for cutworms on the UF/IFAS EDIS website to learn about additional cutworm species found in our area (http://edis.ifas.ufl.edu/).

 

Air Potato Vines and Leaf Beetles

Air Potato Vines and Leaf Beetles

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.

Opportunity for Professional Training

Opportunity for Professional Training

People with lawn care equipmentNo previous experience or accreditation it required to be a landscaper in the state of Florida. So when homeowners are searching for service providers, it is important that they question potential companies about their skills. One good measure is completion of voluntary certifications such as the Florida Nursery, Growers and Landscape Association (FNGLA) Certified Horticulture Professional (FCHP). The FCHP program has been the industry’s standard for measuring horticulture and landscape knowledge since 1984. The training is also useful for property managers, homeowner associations and retail garden center employees, or anyone that wants to know more about Florida’s plants and their care.

 

Plants are complex and variable living things that range from microscopic to the largest of living organisms. With steady population growth in the state of Florida, environmental damage risks created by the use of improper products and practices has continually risen. State and federal natural resource protection agencies have restricted certain horticultural practices, as well as, fertilizer and pesticide application. It takes scientific knowledge to maintain lawns and landscapes, not just a “green thumb” in order to keep plants healthy while reducing contamination to the soil, air and water that we all need.

 

The Florida Certified Horticulture Professional training covers 16 areas, including identification, fertilization, irrigation, pest management, safety and business practices. Lecture and hands-on activities are utilized at each session. The 70-hour course will enhance anyone’s knowledge and will provide the basis for professionals to deliver a skilled service to clientele.

 

If you are a green industry worker or a concerned citizen interested in attending a FCHP preparatory course, there is an opportunity here in Crestview. Beginning Thursday, January 16, 2020 and continuing for 10 weeks to March 19, 2020, the Okaloosa County Extension office will be providing training for $175, which included the newest hard copy manual. Contact Sheila Dunning, 850-689-5850, sdunning@ufl.edu for more information.