One of the things to do while stuck at home due to COVID-19 restrictions, is to look for caterpillars and butterflies in your landscape. I’ve noticed giant swallowtail butterflies (Papilio cresphontes) a little early this year. The giant swallowtail is one of the largest and most beautiful butterflies in our area. Its larval stage is known as the orangedog caterpillar. This unusual name comes from the fact that it feeds on young foliage of citrus trees.
Orangedog caterpillar. Photo credit: Donald Hall, University of Florida
The orangedog caterpillar is mostly brown with some white blotches, resembling bird droppings more than a caterpillar. When disturbed, it may try to scare you off by extruding two orange horns that produce a pungent odor hard to wash off.
I’ve had some minor feeding on citrus trees in my landscape from orangedog caterpillars. But I tolerate them. I’m not growing the citrus to sell. Sure the caterpillars eat a few leaves but my citrus trees have thousands of leaves. New leaves eventually replace the eaten ones. I leave the caterpillars alone. They eat a few leaves, develop into chrysalises and then emerge as beautiful giant swallowtail butterflies. The whole experience is a great life lesson for my two teenagers. And, we get to enjoy beautiful giant swallowtail butterflies flying around in our landscape and still get plenty of fruit from the citrus trees. It is a win, win, win.
In some cases, the caterpillars can cause widespread defoliation of citrus. A few orangedog caterpillars can defoliate small, potted citrus trees. Where you cannot tolerate their feeding habits, remove them from the plant. But consider relocating the caterpillars to another area. In addition to citrus, the orangedog caterpillars will use the herb fennel (Foeniculum vulgare) and rue (Ruta graveolens) as a food source. Some butterfly gardens plant citrus trees to provide food for orangedog caterpillars so that they will have giant swallowtail butterflies. So you could plan ahead and grow some fennel, rue or find a butterfly garden in your area for the purpose of relocating the larvae.
Yellow giant swallowtail butterfly on pink garden phlox flowers. Photo credit: Larry Williams
The adult butterflies feed on nectar from many flowers, including azalea, bougainvillea, Japanese honeysuckle, goldenrod, dame’s rocket, bouncing Bet and swamp milkweed. Some plants in this list might be invasive.
Keep in mind that mature citrus trees can easily withstand the loss of a few leaves. If you find and allow a few orangedog caterpillars to feed on a few leaves of a mature citrus tree in your landscape, you and your neighbors might get to enjoy the spectacular giant swallowtail butterfly.
Florida is home to some amazing and gorgeous plants that are underused and underappreciated in the home landscape. One such plant is an evergreen and easy-care large shrub or small tree known as black titi or buckwheat tree, botanically known as Cliftonia monophylla.
Pink-flowered variety of black titi, Cliftonia monophylla. Photo credit: Mary Salinas, UF/IFAS Extension.
Black titi or buckwheat tree. Photo credit: Chris Evans, University of Illinois, bugwood.com
Black titi is commonly found in wet areas and at the edges of swamps in USDA hardiness zones 7B through 9A from Louisiana through the Florida panhandle and into South Carolina. This is a perfect plant for those areas of your landscape that are low and consistently moist.
Early spring brings clusters of small white flowers at the tips of the branches. Occasionally one can find the pink-flowered variety of black titi in the native nursery trade. These fragrant flowers provide an early season nectar source for bees in February and March. The flowers give way to golden-amber seed pods that resemble buckwheat. The seed pods turn a pleasing orange-brown and persist on the plant through winter. The shiny dark green evergreen leaves along with the seed pods provide an additional ornamental quality to the tree in fall and early winter.
Black Titi golden-amber fruit. John Ruter, University of Georgia, bugwood.org
Paper wasps can hide among vegetation and surprise gardeners. Credit: UF/IFAS
As summer comes to a close, many gardeners are getting their landscapes back in shape after the long, hot summer months. There are likely some large weeds and/or vines that have taken over areas where they are not wanted. As you begin to hack these back, it is wise to be on the lookout for wasps and yellow jackets. These stinging insects pack a punch and are particularly active this time of year.
Wasps and yellow jackets are closely related in the insect family Vespidae. These are social insects, similar to ants and bees, that have a division of labor with a queen and workers (both female) carrying out specific tasks for the colony. Males arise from unfertilized eggs and are only needed for reproductive purposes. Once they mate with a female from another nest, they die. Once the fertilized females emerge in late fall, they will overwinter under the bark of a log, or other safe habitat, until spring, when they start a new colony. Unlike bees, who die after a single sting, wasps, yellowjackets, and hornets can sting multiple times. Yellowjackets and hornets even emit an alarm pheromone that causes other members of the nest to aggressively defend the colony.
While there are many different species of wasp in Florida, including the paper, red, mason, potter, and mud dauber wasps, the paper and red wasps (Polistes spp.) are the ones that tend to be most aggressive when provoked and cause a harmful sting. Their nests are often found under house eaves or hidden in amongst shrubbery. These nests hidden in vegetation are the ones that gardeners typically run into when trimming or weeding.
There are three species of yellowjacket in Florida, including the eastern yellowjacket (Vespula maculifrons), southern yellowjacket (Vespula squamosa), and baldfaced hornet (Dolichovespula maculata). All three can be aggressive and sting humans, especially if they feel threatened, such as when pruning or working over or near a colony. Yellowjackets build extensive colonies underground, though can also build colonies in hay, palm fronds, and other loose debris aboveground. These underground colonies usually have a single entrance but can also have multiple entrance holes. Hornets build aerial colonies. Gardeners are most likely to have run-ins with yellowjackets since hornet nests are typically up in trees and more obvious than an underground yellowjacket colony.
Southern yellowjackets create underground colonies that can hold over 2,000 yellowjackets. Credit: UF/IFAS
While these insects can be a major pain, figuratively and literally, they actually do help out us gardeners. The main food source of wasps, yellowjackets, and hornets are caterpillars and beetle larvae, which are often garden pests. They are also native pollinators. Therefore, it’s best that we accept some in the landscape, manage colonies in high-traffic areas, and prevent encounters with them. To reduce your chance of weeding right into a wasp nest, take a stick and knock around the vegetation to see if any are hiding in the brush before getting started. Be ready to run. Yellowjackets are harder to avoid as they are stealthy in their underground bunkers.
When it comes time to remove these insects from near a structure or heavily trafficked area, you may want to consider hiring a professional pest control company. Wasps can be managed by most homeowners with a broom (if the nest is small and/or relatively inactive) or aerosol insecticides specifically formulated for wasp control. Yellowjackets and hornets are trickier to deal with and should be approached very cautiously. Spraying aerosols into a yellowjacket entrance hole is dangerous and may not be very effective as some colonies can be up to a foot wide and contain over 2,000 yellowjackets. Any attempts to control wasps, yellowjackets, and hornets should be done in the evening when they are less active and with appropriate clothing that covers the skin.
Yellowjackets are pollinators and eat caterpillar pests! Credit: Whitney Crenshaw, Colorado State University, Bugwood.org
For more information on wasps, yellowjackets, hornets, and other stinging insects, see the Biting and Stinging Insects section of the UF/IFAS EDIS site (https://edis.ifas.ufl.edu/topic_biting_and_stinging_pests) or contact your local Extension Office.
Until plans were underway for our UF/IFAS Demonstration Butterfly Garden, I had never heard of Cutleaf Coneflower, Rudbeckia lacineata. Master Gardener Volunteer Jody Wood-Putnam included this gem in her garden design and introduced me and many of our visitors to a new garden favorite.
Although in the same genus as your common Black-eyed Susan’s (Rudbeckia fulgida or R. hirta) this perennial has very distinct differences. Rather than the low growing, hairy, oblong leaves of Black-eyed Susan, Cutleaf Coneflower has smooth pinnately lobed leaves with serrated edges. The leaves are still clump forming but form an almost bush-like shape. By mid to late summer, tall flower spikes emerge and are covered in bright yellow flowers bringing the overall height of the plant over 5 feet tall!
Cutleaf Coneflower is native to North America with several variations adapted to different regions including the Southeast and Florida. This perennial performs well in full sun to part shade and needs a lot of space. Mature plants can reach 3’ wide by 10’ tall and may require staking. The plant can spread through underground runners, so be sure to give it lots of space. In North Florida leaves may be evergreen if winter is mild. Cutleaf Coneflower is a good wildlife attractant providing nectar and pollen for many insects and if you leave the flowers on to mature the seed the is eaten by songbirds, including goldfinch.
To see this plant in person, stop by the UF/IFAS Demonstration Garden at 2728 E. 14th Street, Panama City, FL. If during normal business hours, check in for available seeds from our Pollinator Garden. 850-784-6105
Although blackberries are well adapted to North Florida, many different biotic and abiotic factors can impact fruit production. Photo by Molly Jameson.
Diagnosing Abiotic Blackberry Fruit Disorders
Whether it be wild blackberries you’ve foraged or a prized cultured variety you’ve oh-so-carefully sustained, we are now in prime blackberry season, and there are many sweet, tangy delectable fruits to be eaten.
Blackberry bushes are well adapted to the Florida Panhandle and the plants can be found growing all over – along roadways, in ditches, throughout open fields, and also within forests.
Although wild blackberries and domesticated cultivars thrive in our climate, there is a wide range of factors that could affect blackberry fruiting. When diagnosing plant problems, we tend to blame insects and diseases, but there are many abiotic (non-living) factors that could negatively impact blackberry fruit production. If your blackberry drupelets (the small subdivisions that comprise a blackberry fruit) are compromised, you may be experiencing one or more of the following abiotic blackberry disorders.
Although blackberries can self-pollinate, insect pollination is critical for forming the best blackberries. Photo by Johnny N. Dell, Bugwood.org.
Poor Pollination. Blackberries, strangely enough, are not true berries botanically. True berries only have one ovary per flower (such as bananas, watermelons, and avocados!). Each blackberry flower contains over 100 female flower parts, called pistils, that contain ovaries. To form a fully sized blackberry with many drupelets, at least 75% of the ovaries need to be pollinated. While blackberries can self-pollinate, pollinator insects, such as bees, are very important to ensure adequate drupelet formation. When weather conditions are overly cloudy and rainy, bees are less active. If this coincides with blackberry flowering, you may end up with some blackberries that are nearly drupe-less.
White Drupe. If you notice patches of white and brown drupelets on your most sun-exposed canes, you might have white drupe disorder. When humidity drops and temperature heats up, solar radiation contacting your berries is more powerful, as there is less moisture in the air to deflect the intense heat. Berries that are not protected by leaf coverage, and those on trellises oriented for maximum sun exposure, are most vulnerable to white drupe damage.
Sunscald. Often associated with white drupe, sunscald is most common when temperatures are extreme. Daytime highs in the Florida Panhandle in June and July regularly reach 90°F, if not higher. At these times, fruit exposed to the sun can be hotter than the air temperature around them, which essentially cooks the fruit. As I suspect you’d prefer to cook your fruit after harvest in preparation for blackberry pie, orient your trellis so it gets shade relief during the hottest part of the day and harvest often.
Diagnosing a blackberry issue can be challenging, as there can be more than one culprit impacting the fruit. Photo by Molly Jameson.
Red Cell Regression. One of the not-so-well understood abiotic blackberry disorders is red cell regression, or red drupelet disorder. If you’ve ever harvested blackberry fruit and stored them in the refrigerator for later munching, you may think your eyes are deceiving you when you discover your fruit doesn’t appear as ripe as when you picked it. This regression in color is linked to rapid temperature change, but rest assured, it does not affect the sugar content of the fruit. There are a few things you can do if you think this is affecting your berries, such as harvesting in the morning when the berries are still cool, harvesting when the sky is overcast, or shading your berries pre-harvest. You can also try to cool your berries in stages, perhaps moving from the field, to shade, to A/C, and then to the fridge.
Beyond abiotic stresses, blackberries can also suffer from insect, pest, and disease damage, such as from stink bugs, beetles, mites, birds, anthracnose, leaf rust, crown gall, and beyond. For domesticated blueberry bushes, proper cultivar selection, site selection, planting technique, fertilization, irrigation, propagation, and cane training is important and will allow the plants to grow healthy to defend themselves against any abiotic or biotic nuisance that comes their way.
Our landscapes are becoming important spaces for many animals to find food, water, and shelter. You can enjoy many beautiful plants while supplementing the diet of a favorite garden visitor, the hummingbird. Learn about a couple of nectar plants for hummingbirds and how to properly install your hummingbird feeder In the Garden with UF IFAS Extension Escambia County.
