Yellow Jacket Wasp – Aggression and Understanding

Yellow Jacket Wasp – Aggression and Understanding

It is late summer and many of us enjoy being outdoors in the landscape and taking early morning walks before the temperature rises for the day.  There are precautions to take while being outdoors and the activities as many insects are very active, including the yellow jacket.  Late summer and many of us being outdoor brings us increases the change of being stung by this insect.  The Yellow Jacket sting can be painful and potential dangerous to certain individuals with strong reactions to stings.

Yellowjackets are pollinators and eat caterpillar pests! Credit: Whitney Crenshaw, Colorado State University, Bugwood.org

In the State of Florida there are two species of this Yellow Jacket Wasp, the Eastern Yellow Jacket and the Southern Yellow Jacket.  It is difficult to distinguish between them and for this article I will refer to them as Yellow Jackets.  Yellow Jackets most often colonize in the ground and are often found in lawns that tend to stay dry, landscape beds and edge of woodlands.  Colonies of this flying insect can grow into hundreds or even larger numbers.  Often by observation in morning or evening light the entry and exit point of the nest can be see with some luck.  It looks like an extremely busy airport with lots of landings and departures.  The unfortunate way to find the nest can occur by mowing the lawn disturbing the nest with many yellow jackets emerging from the nest to protect it.  The colony quickly goes into defense mode with vibrations occurring nearby.  This has occurred with me on more than one occasion.  All modesty can be lost while run away from the nesting area with several yellow jackets stinging you move quickly move away.  Clothing has been known to be shed to hopefully remove the yellow jackets busily stinging either under or on the outside of clothing.    

yellowjacket nest
Southern yellowjacket, Vespula squamosa (Drury), nest dug from ground. Credit: Gerald J. Lenhard; http://www.insectimages.org/

During the early part of the spring and summer season yellow jackets are busy foraging for protein sources to feed to queen and young larvae.  During the consuming of the insects, with many of those harvested being harmful insects to plants.  The yellow jackets derive their sugar sources from the larvae secretions as they consume the proteins provided.  This is part of the reason we do not often see Yellow Jackets in late spring and early summer.  As the queen begins to reduce the amount of egg laying, hence the less numbers of larvae to feed and harvest the sugar for a wasp population at its peak creates a more aggressive need to find alternate sources of sugar.   This is part of the reason why yellow jackets show up in greater numbers at outdoor sporting events and other places to look for additional sugar sources.   Sugar water for hummingbirds is another backyard site for yellow jackets to work hard for the sugar.  Even the birds are careful about approaching the feeders. 

I do not advocate the destruction of yellow jacket nesting sites unless they are in proximity to human activity as this can set the situation of stings and potential health challenges for people.  If you identify a nest location do not approach and call a company that specializes in addressing these types of stinging insects.  Keep in mind that this insect provides a benefit in harvest of many harmful pests to plants yet do pose a potential threat.  Be observant as you garden situations that seemed fine last month may have changed quickly.

Summer Tasks

Summer Tasks

Summer should be the time to relax and enjoy the fruit of all the hard work performed in the landscape over the previous winter and spring.  However, there are still some essential tasks that need to be completed during the summer.  Perform them in short energy bursts early in the morning or late in the evening.

1. Aerate Your Lawn

If your yard is starting to look weak and thin, even with fertilizing and proper moisture, it may need aeration.  Aeration, which is creating channels into your lawn, allows water and nutrients to reach the deep roots of your grass more efficiently.

To test if you need to aerate your lawn, shovel up a patch of grass to a depth of at least four inches.  If the layer of thatch is a half-inch thick or higher, your yard would benefit from aeration.  There are self-drive aeration machines and tractor-pulled devices you can rent to make quick work of large areas.  For smaller areas, simply punching multiple holes with a pitchfork will do the job.

2. Fertilize

Gardener fertilizing yard
Commercial landscape fertilizer applicators must obtain state certification.

Turf grass often displays a yellow color during the mid-summer rainy seasons due to the heavy rains flushing nitrogen away from plant roots. If your lawn is looking sad and yellow, chelated iron can often give a temporary green-up. Iron is not a replacement for nitrogen, but it can work well during our summer rainy season.

If you soil test revealed a potassium or magnesium deficiency, summer is a good time to make the last corrective application.  Potassium (K) is an essential macronutrient. Fertilizer bags typically show the percentage of potassium in a product as the third number displayed on the front of the bag (e.g., the “8” in 16-2-8). Potassium acts as a “vitamin” for turf grass, increasing root strength, disease resistance and cold hardiness.

Magnesium (Mg), also a macronutrient, is essential for the production of chlorophyll, necessary for photosynthesis, and also plays a part in the movement of carbohydrates from leaves to other parts of the plant.

3. Don’t Mow Too Short

It’s a natural inclination to want to mow your grass as short as you can, so you have the longest time until you have to mow it again. However, giving your grass a buzz cut every time you mow can hurt your lawn over time.

While some turf grasses can be mowed relatively short, like Bermudas and some Zoysias, most grass types shouldn’t be cut shorter than two-and-one-half to four inches high.  Mowing shorter than that can damage the growth point and leave it susceptible to disease and pest infestation.  It can also dehydrate the grass and lead to long term damage.

5. Water Infrequently but Deeply

One common mistake made by many is watering too often and too shallow.  When only given frequent shallow waterings, grass will begin to grow their roots upwards to take advantage of the small amounts of water, which makes weak and unhealthy.  The grass becomes even more dependent on water and very susceptible to disease and insect attack.

Try watering only once or twice a week, but for a considerably longer time so that the water can penetrate deeper into the soil and encourage downward roots.  Ideally, each irrigation zone is calibrated to determine the length of time it take to deliver ½ – ¾ inch.  Then set the system to run every 3-4 days for that number of minutes.  While checking the irrigation delivery system, make sure the rain shut-off device is working and set to the same ½ – ¾ inch.

6. Prevent Mosquitoes

Summer rains on a nearly daily basis lead to lots of standing water. In less than one inch of water, hundreds of mosquitoes can hatch 3 -5 days later. Not only are these blood-sucking pests annoying, but they can also transmit dangerous diseases like West Nile and Zika Virus.  Even without disease, their bites are painful and irritating.

To prevent mosquitoes, make sure no standing water is allowed to remain in your yard, either in low points or in empty containers like flower pots or wheelbarrows.  Any amount of stagnant water is the perfect breeding ground for mosquitoes.  Take a walk around the yard, dumping out water and disturbing the oak and magnolia leaves that are acting a collection cup.  Treat birdbaths and water features with floating “donuts” specifically designed to kill mosquito eggs.

While getting tasks done in quick morning trips to the yard, make sure to keep hydrated.  Heat exhaustion can happen fast.

Going bats for insect control

Going bats for insect control

The Case for Bats

Biological control is a pillar of integrated pest management.  It may seem a bit daunting the principle is simple.  All things in nature have predators including insects.  Biological control is simply building a conducive environment for the predators of undesired pests.  One animal not often thought of in this capacity is bats.  Insectivores by nature, these underutilized creatures have a big impact to your open spaces.  Their steady diet of moths (Lepidoptera), beetles (Coleoptera) and flies (Diptera, which includes mosquitoes) reduce insect pressure to your gardens and landscaping.

I know what you are thinking.  How effective can they possibly be?  Pregnant females consume up to two thirds of their body weight through the summer months while rearing pups.  Bats are small but keep in mind that these are not solitary animals.  In south Texas, a single large colony consumes enough insects to save cotton farmers an estimated $741,000 per year in insecticides.  That is just to illustrate the point as you won’t be able to attract huge colony.  There is no reason to believe a smaller colony will not provide similar services in your gardens.

Habitat

Now that your interest is piqued, how can you attract bats to your property?  Installing a bat house is the easiest way.  They are typically a two foot by one foot structure holding single or multiple chambers in which bats roost.  It provides shelter from predation and weather while providing a place to rear pups.  Though commercially available they may be built at home with minimal cost.  Place the bat house in a location with morning sun at least 12 feet off the ground.  Ensure there is enough airflow around the house to keep them cool, but that the structure is watertight.  Mount houses on poles next to buildings and you’ll have better success attracting residents.  With everything in place, it is time to discover who will most likely be your new neighbor.

bathouse on pole

photo: Joshua Criss

 

The Bats of North Florida

Florida is home to 13 species of bats statewide.  Of these, 11 may be found in the Panhandle but only 3 are common enough to be routinely seen.  The Brazilian free-tailed bat (Tadarida brasiliensis) is the most common.  Medium sized with brown fur, they have a long tail, wrinkled cheeks, and roost in man-made structures.

Brazillian free tail bat

Photo: IFAS

Second most common are Evening bats (Nycticeius humeralis).  These dark brown to yellow bats have short ears with a broad hairless muzzle.  They are tolerant of other bat species often roosting in tandem with them.

Evening bat

Photo: IFAS

Finally, the panhandle is home to Southeastern Myotis (Myotis austroriparius).  Easily the smallest of these bats, they are dull gray to brown with a lighter belly and long hairs between their toes.  This species is the bat most likely to eat mosquitoes.

Southeastern Myotis

Photo: Jeff Gore, FWC

Finally, the panhandle is home to Southeastern Myotis (Myotis austroriparius).  Easily the smallest of these bats, they are dull gray to brown with a lighter belly and long hairs between their toes.  This species is the bat most likely to eat mosquitoes.

A Word of Caution

No article on wildlife would be complete without a word of caution.  Bats are wild animals and should be treated as such.  Never touch a bat on the ground as it most likely is not healthy.  Bats do not generally cause issues but have been known to be disease vectors.  Call a professional to collect the animal and never bring it into your home.

Bats can be a wonderful tool in controlling pests on your property.  Creating habitat can help reduce pesticide need and cost to the homeowner.  For more information on bats, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.

 

The Fleeing Beetle

The Fleeing Beetle

Photo credit Lyle J. Buss, UF/IFAS

The unwanted guest- Flea beetle

Having trouble with flea beetles? Tired of them showing up unannounced? Do not be alarmed here are a few tips to get rid of the unwanted guest in your garden.

Description: Flea beetles vary in appearance, where colors range from black to tan, with other, brighter colors mixed. They may also have a solid, striped, or spotted pattern depending on the species. Beetles are tiny with large hind legs which allow them to jump like fleas when disturbed.

Lifecycle: These unwanted guests will overwinter as adults in the soil or beneath plant debris and become active in early spring when temperatures reach 50°F, and begin feeding on weeds or early-planted crops. Eggs are laid by adult flea beetles normally around May in the soil or at the base of host plants. After 7-14 days eggs will hatch and larvae will feed and develop on various plant parts. They pupate in the soil for 11-13 days before emerging as adults.

Host plants:  Some species attack a wide range of plants, while others target only certain plant families. (Table 1).  In the garden, several vegetable crops are eaten by these pests, particularly those in the Brassica family.

Table 1: Common flea beetles and host plants.

Scouting:  Adult flea beetles are particularly active on warm, sunny days. To identify damages, scout every 1-2 days in newly planted fields, since it is easier to identify the damages than to see the beetles themselves. Flea beetle populations can be monitored with yellow sticky traps. 

Damage: Adult beetles feed on foliage, producing shot holes in the leaves, especially new leaves which will have a lacy appearance. Additionally, in leafy crops like lettuce or spinach, the holes can reduce the quality of the leaves.

Photo Credits: Jeffery Hahn University of Minnesota

Photo Credit : Jeffery Hahn University of Minnesota.

Management / Control strategies:

  • In the spring delay transplanting or planting by a couple weeks if possible.
  • In the fall, till the garden to uncover any hiding flea beetles.
  • Plant “push” or repellant crops such as catnip, sage, mint, hyssop, nasturtium, and basil.
  • Use a “trap crop” such as radishes, taking the pest’ focus off more valuable plants.
  • Dusting leaves with plain talcum powder repels flea beetles on tomatoes, potatoes, peppers, and other plants.
  • Insecticides may be used early in the season.
  • Water deters adult flea beetles. Any watering should be done in mid-day.
  • Planting after adults have emerged or crop rotation can help minimize flea beetle damage.
  • Apply commercially available nematodes that feed on flea beetle eggs, larvae, and pupae.

Supporting information for this article can be found in the UF/IFAS EDIS publications EENY-721/IN1238: Flea Beetles of the Genus Altica: Altica spp. (Insecta: Coleoptera: Chrysomelid) (ufl.edu); https://entnemdept.ufl.edu/creatures/ORN/BEETLES/flea_beetle.html and https://extension.uga.edu/content/dam/extension/programs-and-services/integrated-pest-management/documents/insect-pdfs/fleabeetles.pdf

Method for Trapping Pesky Deer Fly

Method for Trapping Pesky Deer Fly

Deer fly trap as created by Dr. Russ Mizell

Deer fly trap. Photo credit: Russ Mizell

Recently, I’ve been asked about a deer fly trapping method that I wrote about a number of years ago. So, here it is. This aggravating insect is active now.

Deer flies, which are in the horsefly family, are annoying as they repeatedly and persistently dive for their victims until they inflict a painful bite.

Dr. Russ Mizell, now retired UF/IFAS Extension entomologist, experimented with a method to trap this insect. Mizell wanted to identify the optimum shape, size, color and speed to attract deer flies. If successful, he could temporarily remove a deer fly population long enough to enjoy an outdoor gathering without being bothered by deer flies.

Mizell said he started the research as a high school science project with his son but “it got so interesting, I just kept doing it.”

Deer flies wait for prey to walk before attacking. So, they are highly attracted to movement.

With this in mind, Mizell and his son decided the best way to snare deer flies was to “troll” for them from a slow-moving vehicle. Working in spring and summer when deer flies are most prominent, they set out to discover what kind of trap worked best.

They built a test platform on the hood of their vehicle that could troll seven different shapes at once. They ambled along in deer fly-infested countryside for set periods of one to five minutes, testing pyramids, squares, balloons, plant containers and other shapes, all coated with Tanglefoot (commercially available sticky spray for insects), then counting immobilized prey. They tried black, tan, blue and shapes of other colors suspended from various heights.

The trap that enticed the most deer flies proved to be a 6-inch flowerpot painted bright blue and coated with Tanglefoot. This trap captured as many as 30 deer flies in a one-minute test. It worked best when suspended three to six feet above the ground and trolled no faster than 10 feet per second or about 7 miles per hour.

The traps are remarkably effective, Mizell said. “Many times, after running the traps through an area, we found there were no deer flies left,” he said. “You trap them out for a short period until they repopulate the area.”

The traps also work when attached to a baseball cap and trolled by the hat’s wearer. But instead of attaching a flowerpot to your cap, you could attach a blue drink cup painted with Tanglefoot.

Despite its effectiveness, its aesthetic appeal leaves something to be desired.

For more information including instructions and pictures of how to make a deer fly trap visit the below site. http://entomology.ifas.ufl.edu/pestalert/deerfly.htm

Protecting Yourself From Mosquitoes

Protecting Yourself From Mosquitoes

Mosquitoes are a pesky nuisance we’re all too familiar with, especially as we move into the summer months. Their presence can certainly make being outdoors undesirable. Not only are they a blood-sucking nuisance but they also carry and can transmit many diseases to humans. Mosquito-borne diseases of public health concern in Florida include St. Louis encephalitis, eastern equine encephalitis, West Nile virus encephalitis, dengue, and Zika. While it can be difficult to eliminate mosquito populations completely, there are steps we can all take to protect ourselves and to prevent our landscape from becoming a major breeding ground for mosquitos.

Asian Tiger Mosquito. Photo Credit: James Newman. UF/IFAS Photo.

Source Reduction

One way to keep mosquito populations down is to prevent the landscape from being a breeding ground for them. Many species of mosquitoes require standing water to lay their eggs; therefore, eliminating standing water can help keep populations low. Mosquitoes can develop in a variety of water-holding containers such as flowerpots, birdbaths, pet dishes, tree holes, bamboo trunks, and many others. It is important to:

  • Drain water from garbage cans, gutters, buckets, coolers, or any other containers where water is collected
  • Discard any old tires, bottles, broken appliances, or items not being used that could potentially hold water
  • Change water in birdbaths and/or outdoor pet dishes once or twice a week

Mosquito larvae. UF/IFAS File Photo

For areas such as ornamental ponds or water gardens, aeration or stocking them with mosquitofish (Gambusia species) can also help to keep mosquito populations down. The small fish will feed on the mosquito larvae and add movement to the water. They are most effective in small ponds with no other fish present.

For other areas with standing water that cannot be drained, such as rain barrels or ornamental ponds, products containing Bacillus thuringiensis israelensis (Bti) are effective in controlling mosquito larvae. Products containing Bti come in the form of granules or “dunks”, which look like miniature donuts. These Bti products are considered a form of biological control as it is a naturally occurring bacteria that is specific to mosquito, blackfly, and fungus gnat larvae. Therefore, Bti products are not harmful to fish, waterfowl, pets or humans when used according to label directions.

Protective Clothing and Repellents

The most effective way to protect yourself from mosquito bites is to avoid infested areas, wear protective clothing, and wear insect repellent when outdoors. There are several repellents that are currently available such as DEET, picaridin, and IR3535, or plant derived chemicals such as citronella and oil of lemon eucalyptus.

It is important to read the label before applying mosquito repellent and to remember that there are different recommendations for frequency of application for different products. Below is a table comparison of products based upon University of Florida research.

Table from UF/IFAS Publication: Mosquito Repellents

For more in-depth information on selecting mosquito repellents, please visit the UF/IFAS Publication: Mosquito Repellents.

For more information about mosquitos, please visit: