For the 13th year we celebrate National Pollinator Week June 22-28 to bring awareness to the importance of our pollinators and the challenges they face. This is an opportunity to learn about ways to protect pollinators in our own landscapes. Every one of us can make a difference.
When we hear the word ‘pollinator’ most of us immediately think of honeybees. They are very important but there are so many other creatures that are important pollinators:
Native bees – Florida alone has over 300 species of bees
Hummingbirds – their long beaks can reach into long, tubular blooms
Bats – they pollinate over 500 plants including banana, mango, and agave (used to make tequila)
Beetles – considered to be a messy and minor pollinator; they pollinate the native paw paw
Butterflies – a minor pollinator as most have long legs that keep them perched above the pollen
Flies – pollinators of a variety of native plants
According to the USDA, 75% of flowering plants and about 35% of food crops around the globe rely on these animals for pollination. Without pollination, these plants would not reproduce or provide us food.
So, what can the average person do to make a difference?
Avoid using any insecticide unless it is absolutely necessary. Predators like assassin bugs, dragonflies and birds help to keep pests in check. Our songbirds rely on protein-rich insects (especially caterpillars) to feed their growing babies.
Don’t treat areas where pollinators are visiting the flowers, whether in the lawn or the landscape beds.
If you need to apply an insecticide to the lawn, mow first to remove the blooms from any weeds. Always follow the label instructions carefully.
Avoid using a systemic insecticide on plants that bloom and attract pollinators. The insecticide can remain in plants for a long time.
The bay laurel tree in the Escambia County Demonstration Garden had some dead branches on the outer canopy. Further investigation led us to the culprit, the black twig borer. Learn more In the Garden with UF IFAS Extension Escambia County.
Wheel bugs have large beaks and a distinctive semicircular crest on their backs resembling a cogwheel. Photo by Gerald J. Lenhard, Louisiana State University, Bugwood.org.
As a gardener, the summer is the season you might feel it takes knightly status to grow fruits and vegetables. You put on your metaphorical armor, hold up your shield, and draw your sword to battle the stink bugs, squash vine borers, armyworms, green peach aphids, and more.
In these instances, it may feel like nothing in nature is on your side. But alas, there are a few insects out there that carry their own defenses. One of them is the ferocious assassin bug. These insects are predacious, loaded with powerful curved beaks called proboscises that pierce their unsuspecting prey. Once pierced, the assassin bug injects a toxin that liquefies the muscles and tissues of the prey. It then sucks out the liquefied tissue, killing its host.
Although milkweed assassin bugs vary in appearance worldwide, those found in the United States are distinctly orange and black. Photo by Gerald J. Lenhard, Louisiana State University, Bugwood.org.
Assassin bugs feed on a wide range of insects, including many types of caterpillars, stinkbugs, aphids, flies, beetles, and even mosquitoes.
While assassin bugs are our garden allies, be mindful, as their injection does pack quite the punch! Fortunately, although a “bite” from an assassin bug is painful, they do not generally require medical attention. But do seek medical attention if it causes any type of allergic reaction such as swelling, itching, hives, or difficulty breathing.
There are nearly 3,000 known assassin bug species, including many in Florida. Common species you may come across in your Florida garden are the wheel bug (Arilus cristatus) and the milkweed assassin bug (Zelus longipes). Give them their space but know that they are on your side.
Fig. 1 An adult redbay ambrosia beetle compared to the size of a single penny. Credit: UF/IFAS File Photo.
While most bark beetles are important in forest ecology by recycling fallen dead trees and eliminating sick and damaged trees, some of them may impact healthy trees. A group of bark beetles that has become a major concern to forest managers, nurseries, and homeowners is the ambrosia beetle. Ambrosia beetles are extremely small, 1-2 mm in length, and live and reproduce inside the wood of various species of trees (Fig. 1). Ambrosia beetles differ from other bark beetles in that they do not feed directly on wood, but on a symbiotic fungus that digests wood tissue for them. Every year, non-native species of ambrosia beetles enter the United States through international cargo and we have now nearly forty non-native species of ambrosia beetles confirmed in the United States. Among them, the redbay ambrosia beetle (Xyleborus glabratus), originally from Southeast Asia, is the vector of the fungal pathogen causing laurel wilt, a disease that devastated the Lauracaea population in the southeastern USA, killing millions of redbay, swamp bay, sassafaras and silk bay.
Fig. 2: A mature dooryard avocado tree with large sections of dead and missing leaves, caused by laurel wilt disease. Summer 2009 Impact Magazine image. Credit: UF/IFAS File Photo.
When these beetles attack a laurel tree, the symbiotic fungus is vectored to the tree’s sapwood after the beetle has tunneled deep into the tree’s xylem, actively colonizing the tree’s vascular system. This colonization leads to an occlusion of the xylem, causing wilting of individual branches and in a matter of weeks progresses throughout the entire canopy, eventually leading to tree death (Fig. 2). The laurel wilt disease has spread rapidly after the vector was first detected in Georgia in 2002. The redbay ambrosia beetle was first detected in Florida in 2004, in Duval County, attacking redbay and swamp bay trees. At this point, it is estimated that more than one-third of redbay in the U.S.A., 300 million trees, have succumbed to the disease.
Starting in 2017, we examined the efficacy of verbenone against redbay ambrosia beetle in live laurel trees in a natural forest setting. Verbenone is an anti-aggregation pheromone that has been used since the 1980’s to protect lodgepole pine. Verbenone also has the potential to be used over large areas and is currently being used to protect ponderosa pine plantations from the Mountain Pine Beetle in the western US.
We have found verbenone to be an environmentally friendly and safe tool to prophylactically protect laurel trees against redbay ambrosia beetle. Our protocol consists of the application of four 17 g dollops of a slow-release wax based repellent (SPLAT Verb®, ISCA technology of Riverside, CA) to the trunk of redbay trees at 1 – 1.5 m above ground level (Fig. 3). The wax needs to be reapplied every 4 months during fall and winter and every 3 months during spring and fall when temperature is higher. When compared to the control trees without repellents, we found that trunk applications of verbenone reduced landing of the redbay ambrosia beetle on live redbay trees and increased survivorship of laurel trees compared to untreated trees (Fig. 4). Verbenone should be considered as part of a holistic management system against redbay ambrosia beetle that also includes removal and chipping of contaminated trees.
If you have Redbay or other bay species on your property and are concerned about Laurel Wilt Disease or Redbay Ambrosia Beetle damage, contact your local UF/IFAS Extension Agents for help!
This article is courtesy of Dr. Xavier Martini and Mr. Derek Conover of the UF/IFAS North Florida Research and Education Center (NFREC) in Quincy.
Fig. 3: Application of SPLAT Verb on a redbay tree during a field trial
Figure 4: (A): Cumulative capture of redbay ambrosia beetles Xyleborus glabratus following a single application of verbenone vs untreated control (UC). (B) Survivorship of redbay and swamp bay trees treated with verbenone on four different studies conducted in 2017 and 2018.
The insect ground pearls can damage many types of turfgrass in North Florida. Learn to identify ground pearl damage and find the insects in your soil with Larry Williams, Horticulture Agent with UF IFAS Extension Okaloosa County.
Two-Lined Spittlebug. Photo courtesy of Evan Anderson.
Problems with turfgrass come in all shapes and sizes. One that may affect your lawn is an insect that has two very distinct life stages. Named for the two distinct stripes on its back, the two-lined spittlebug looks like a plant or leafhopper during its adult life. When it is young, however, it is often camouflaged and not readily visible. The small green nymph hides in a mass of white froth or spittle that it secretes for protection.
The two-lined spittlebug is not a picky eater, though it cannot harm people or pets. It feeds on a variety of plants, piercing the stem or leaves with its mouthparts and sucking out the juices within. While it may not be picky, it does have favorites. Holly bushes are one food of choice for this pest and centipedegrass is another, so those growing this grass should keep an eye open. The protective spittle masses are usually close to the ground, so they may not be readily visible from above.
Centipedegrass displays feeding injury from spittlebugs in the form of purple or white striping along its leaf blades. If infestations are particularly heavy, the grass may turn yellow, then brown, and eventually curl up as the leaves die. Populations of the adults that cause most of this damage are typically largest in June, with another spike around August or September as the year’s second generation matures. Years with excess rainfall in spring and summer will see increased numbers of spittlebugs.
Spittlebug damage on Centipedegrass. Photo courtesy of Larry Williams, Okaloosa County Horticulture Agent.
If you are having a problem with these pests, make sure you are keeping your lawn as healthy as possible with good cultural practices. Proper watering, fertilization, and mowing to the appropriate height can all help to keep grass strong enough to withstand pests. Remove excess thatch, as it holds moisture and can favor the growth of spittlebugs.
Insecticides may be used to help with control as well. Options for Florida include pyrethroids such as bifenthrin, permethrin, and cyfluthrin. Products with the active ingredients imidacloprid and carbaryl are other options. Read the label of any product you choose. If you have questions or need help in identifying a pest problem in your lawn, contact your local Extension office.
