Florida beekeepers are on high alert as the invasive Vespa velutina hornet poses a threat to honey bees, prompting vigilant monitoring to safeguard against potential impacts. Photo by Danel Solabarrieta, licensed under CC BY-SA 2.0.
A concerning discovery has emerged in Savannah, Georgia, regarding the yellow-legged hornet, commonly known as the “murder hornet’s cousin.” Officially identified as Vespa velutina by the Georgia Department of Agriculture in August 2023, it was first encountered by a beekeeper in the area.
The size of a nickel, Vespa velutina has distinctive black and yellow coloring with yellow/white legs. Photo by Gilles San Martin, licensed under CC BY-SA 2.0.
Although distinctive from the infamous “murder hornet,” the yellow-legged hornet, initially confirmed in Vancouver and the neighboring Whatcom County in Washington state, both hornet species pose threats to honey bee larvae and adults.
Approximately the size of a nickel, Vespa velutina features distinctive black and yellow coloring with yellow/white legs, earning it the nickname “yellow-legged hornet.” The discovery of the yellow-legged hornet has therefore spurred proactive measures to prevent its establishment in Florida and the rest of the United States.
The invasive nature of the yellow-legged hornet, originating from Southeast Asia and first appearing in Europe in 2004, poses a significant threat to beekeepers. This is due to its status as a generalist predator with honey bees as a primary target, intensifying concerns within the beekeeping industry.
The life cycle of the yellow-legged hornet begins with a single queen establishing a nest, laying eggs, and awaiting the emergence of workers. Nests can be found in various locations, growing to an average of 6,000 individuals. Predation on honey bee colonies increases during the summer months, with the hornets mating later in the year. The annual life cycle concludes with the death of all workers and males, and new nests are constructed in the following year.
Vespa velutina secondary nest, with adult hornets huddled together warming up in the sun. Photo by YVO-Photos, Adobe Stock.
Remarkably, a single mated female has the potential to initiate a new colony. Primary nests, starting as small as a tennis ball, undergo significant expansion. Secondary nests, reaching heights of up to one meter and containing over 17,000 cells, are typically situated at altitudes of 60 to 70 feet, making them challenging to access. A single hornet nest has a voracious appetite, as it can consume up to 25 pounds of insect biomass in a single season, underscoring the ecological impact of yellow-legged hornet colonies.
As a predatory wasp, the yellow-legged hornet feeds on a variety of arthropods, displaying opportunistic behavior, including feeding on decaying animals. While the ecological impact is not fully understood, DNA in the gut of hornets shows that they feed on other wasps, bees, butterflies, moths, and spiders. However, honey bees, particularly Apis mellifera, are preferred targets, posing a significant threat to the beekeeping industry. Reports from Europe suggest that up to 30 percent of honey bee hives are weakened by attacks, with approximately five percent facing complete destruction.
A male Vespa velutina, which exhibits longer, thicker antennae compared to females and, in line with all Hymenoptera males, lacks a stinger. Photo by Gilles San Martin, licensed under CC BY-SA 2.0.
Initially attracted to the honey bee hive by hive pheromones, yellow-legged hornets position themselves away from hive entrances, waiting for returning foragers, resulting in a “carpeting” of workers at the entrance. This term refers to the clustering or accumulation of honey bee workers near the hive entrance as they attempt to defend against the invading hornets. This behavior unfortunately leads to decreased colony production.
It’s essential to note that there are many domestic species, native to the United States, that closely resemble the invasive hornet but do not pose a threat to honey bees; in fact, many of them are valuable pollinators. The USDA has a photo gallery of these lookalikes, which can be accessed by visiting www.aphis.usda.gov and searching for ‘yellow-legged hornet.’
Vigilance from the public is crucial in minimizing the potential impact of Vespa velutina on honey bee populations in Florida and beyond. Photo by Danel Solabarrieta, licensed under CC BY-SA 2.0.
While the yellow-legged hornet can easily be confused with other hornets that are not problematic to honey bees, residents who believe they have identified Vespa velutina are encouraged to call the FDACS hotline at 1-888-397-1517.
If a sample is collected or a clear photo of the suspected hornet is available, please email dpihelpline@fdacs.gov along with location information to facilitate monitoring efforts. Vigilance and cooperation from the public are crucial in minimizing the potential impact of the yellow-legged hornet on honey bee populations in Florida and beyond.
Many of the Mexican petunia plants, Ruellia simplex, growing in the landscape along the Gulf Coast are covered in white patches. The leaves appear to be growing fur, actual hairs, much denser than the dust of powdery mildew fungus. Excessive development of leaf trichomes, or surface hairs is referred to as erinea. The “fuzz” is the plant’s response to the feeding of eriophyid mites, also called gall mites. These native tiny, microscopic mites feed on the Mexican petunia leaves and stems, causing the plant to produce the white velvety masses. The distorted tissue provides shelter so the mites can continue to feed without being impacted by the weather or contact pesticide applications. Hot, dry conditions favor mite population increases. We have had plenty of that. However, the native mites are not likely to kill the invasive Mexican petunia, so they are not acting as an effective biological control for the plant.
Mexican petunia damage from the eriophyid mite.
Control of this native eriophyid mite begins with heavy foliage removal. Cutting the plants back to just a few inches above the ground removes the infested portion of the plant. The pruned parts need to be placed in a tightly sealed plastic bag before being sent to the landfill. If the location allows burning on-site, that is an even better option. Remember that these mites can feed on many other plants if allowed to escape. They have caused galls in crape myrtle, loropetalum, and hollies, as well as, vectoring diseases like rose rosette.
Then comes the tough decision. If the Mexican petunia is not one of the new sterile cultivars should the new growth be protected as it grows back? If you didn’t plant them or don’t remember what they were called when you purchased them, there is still a way to determine whether they are the invasive Mexican petunia or not. Invasive Mexican petunia produces seed after flowering. Were there any seed pods on the pruned parts? If so, you may consider killing off the entire planting. Several applications of a total vegetation herbicide with surfactant will remove them, leaving you a spot for a new purple flower, maybe a porterweed (Stachytarpheta), verbena or blue salvia.
Blue porterweed can be a substitute for non sterile Ruellia. Photo by Beth Bolles UF IFAS Escambia Extension
If your plants are sterile (have no seed pods), an application of horticultural oil and/or a miticide like abamectin sprayed with each flush of new growth will produce a pretty bed of purple flowers in a short period of time.
Pesticides can be helpful tools in the home landscape and garden, helping to protect fruits, vegetables, and landscape plants from pests. While pesticides can be valuable tools in controlling pests, their improper use can pose risks to human health, beneficial organisms, and the environment. One crucial aspect of responsible pesticide use is understanding and interpreting the pesticide label. The label provides information on how to mix, apply, store, and dispose of a pesticide product to ensure the safety of the user and the environment.
First, it’s important to recognize what a pesticide is. A pesticide is a chemical substance or mixture used to kill or repel pests. Pests can include insects, weeds, plant pathogens, nematodes, mold, nuisance animals, and other organisms that can injury crops, plants, structures, or cause harm to human health. If you are unsure whether a product is considered a pesticide or not, the label will have an Environmental Protection Agency (EPA) number listed. This number is the EPA’s stamp of approval for the product to be sold and used as a pesticide (Figure 1). In the example shown in Figure 1, the EPA registration number is found on the back page of the pesticide label.
Figure 1. Example of EPA Registration Number found on a pesticide label.
A pesticide label is the information on or attached to the pesticide container and is more than just a piece of paper. This document is a legal document. If you’ve contacted your local Extension office for pest control assistance, you’ve likely heard “follow the label – the label is the law” repeatedly. That is because the label is a contract between the product manufacturer, the Environmental Protection Agency (EPA), and the end user.
What information does the label contain?
Brand or Trade Name: The brand, trade, or product name is used to identify and market the product. It is found on the front panel of the pesticide label. For example, in Figure 2, the brand name of the pesticide is “Complete Insect Killer”. Different manufacturers may use different brand names to market products, even if the same pesticide active ingredient is used.
Active Ingredient: The active ingredient is the chemical that is responsible for killing, repelling, or controlling the target pest. The front panel of the label identifies the name and percentage weight of each active ingredient.
Child Hazard Warning: The front panel of every pesticide label must have the statement “KEEP OUT OF REACH OF CHILDREN” due to poisoning being a major cause of injury to children.
Signal Word: A pesticide label must also display a signal word on the front panel of the label to identify the relative toxicity of the product. Since all pesticides are poisons to some extent, it’s important to note that they do pose some risk. The signal word is based on the entire contents of the product, not just the active ingredients. Signal words are:
DANGER: Highly toxic
WARNING: Moderately toxic
CAUTION: Slightly toxic
Figure 2. An example of the front panel of a pesticide label.
Personal Protective Equipment (PPE): The type of clothing that must be worn during the handling mixing process to protect the applicator from harm.
Statement of Practical Treatment: The statement of practical treatment or first aid statement, describes what to do if a person is exposed to the pesticide.
Directions for Use: This section of the label is the bulk of a pesticide label. This section provides detailed instructions on how to correctly apply the pesticide, including the site where the product may be used, application method, amount of pesticide that should be applied, timing of application, and frequency. It will also contain information on restrictions (if any) on product use including weather, time of day, season of year, contamination of sensitive areas, etc. Applying a pesticide to a site not listed on its label is illegal.
Storage and Disposal: Each pesticide has general storage and disposal instructions. Most pesticide labels will contain a general statement to the effect of “do not contaminate, water, food, or feed by storage, disposal, or cleaning of equipment” and “store in original containers only”. This section of the label provides guidance on how to store the product safely, including temperature requirements, shelf-life, and precautions to prevent contamination. It also outlines guidelines for disposing of unused pesticides or empty containers to prevent environmental harm.
Pesticides can be a valuable tool if used correctly. The first step in using a pesticide safely is to read the product label to learn about how the product may be used. For more information on understanding pesticide labels or for assistance with interpretation, please contact your local Extension Office.
I was recently asked what kind of fungus was affecting a plant brought into the UF/IFAS Leon County Extension Office. Upon close inspection, it was not a fungus at all, but turned out to be damage from spider mites and the little critters were right there on the plant.
Spider mites along the bottom of the leaf. Credit: Mark Tancig, UF/IFAS.
Spider mites, as the name implies, are eight-legged creatures that are kin to spiders and in the mite and tick group of arachnids. They can cause damage to ornamental, fruit, and vegetable plants, especially in hot, dry weather or when grown in greenhouses or indoors. The plants that came into the office had been growing in a greenhouse.
Spider mites are a piercing, sucking pest that pierce their mouthparts into the leaf tissue to suck out nutritious plant saps. High densities of spider mites can pull enough plant tissues out to cause a light colored, grayish look to the leaves, somewhat resembling downy mildew damage. Upon close inspection, small brown to red dots on the bottom of the leaf and/or spider web-like webbing along the stem and petioles may be observed, confirming the identification of spider mites.
Webbing caused by high numbers of spider mites. Credit: UF/IFAS.
Plants grown outdoors don’t usually experience spider mite damage, as natural predators such as lady beetles, minute pirate bugs, thrips, and lacewings provide biological control. For spider mite infestations on houseplants or in greenhouse operations, control can be achieved through physical and chemical control. As part of an integrated pest management plan, regular monitoring of these plants can help identify problems before they get too bad. Sprays of water and rubbing undersides of leaves can remove many spider mites and provide control of small populations. If that doesn’t take care of them or they are at infestation level, insecticidal soaps and horticultural oils can provide adequate control.
Remember that correct identification is key to properly controlling a pest. If the damage was treated as a fungus and a fungicide sprayed, the pest would not be controlled, and time, money, and product would be wasted. If you have questions regarding what is ailing your plants, contact your local UF/IFAS Extension office.
Are you an avid gardener and looking to step it up a notch? Are your gardening eyes bigger than your dinner plate? If you have ever considered selling your bounty for market, you will certainly need to do your homework! One such step you can take is to attend the UF/IFAS Panhandle Extension Team’s So You Want to be a Farmer? Workshop Series.
There’s a lot to know if you want to get into this business! This series aims to introduce new or potential farmers to innovative and environmentally safe production practices, concepts of soil and water management, integrated pest management, how to grow for a farmers’ market, and farm financial management.
Agricultural professionals are actually in high demand. There is an estimated 60,000 highly skilled jobs in agriculture available annually, but only about half of these positions are being filled by graduates in agricultural fields. Additionally, Florida’s farmers are an aging group, and there was an 8% decrease in the number of farms and 26% decrease in acres of cropland from 2002 to 2012.
Fortunately, demand has greatly increased in recent years for locally produced specialty crops, meats, and dairy. There has also been an increase in the number of direct marketing opportunities and small farmers have been able to adopt new technologies, such as season extension techniques and local online marketing, to generate more revenue on small acreages.
The UF/IFAS Extension Panhandle Agriculture Team is hosting the So You Want to be a Farmer? Workshop Series to assist beginning or novice farmers as they navigate the many challenges of getting started.
If you are interested in attending, please register on the So You Want to be a Farmer? Eventbrite page. The cost is $10 per session, with sessions at multiple locations within the east Florida Panhandle.
Please see workshop dates and further details below:
