by Joshua Criss | Jul 14, 2022
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.
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.
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.
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.
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.
by Molly Jameson | May 23, 2022
Use traps crops, such as sunflowers and sorghum, to lure pests away from your crop. Photo by Molly Jameson.
To be a successful gardener, it is important to have an integrated approach to handling obstacles in the garden.
Aphids were lured into this sorghum seed head, which then attracted mealybug destroyer larvae, which are excellent garden predators. Photo by Les Harrison.
These considerations include techniques such as planting disease resistant crop varieties, maintaining proper plant spacing, planting at the appropriate time, monitoring the garden and properly identifying insects and diseases, watering uniformly, and many more cultural and preventative measures that will aid in a garden’s success.
As we transition from the relatively mild and dryer days of late spring into the hot and humid punishing days of summer, we often encounter more and more problems in our gardens.
Insects are commonly one of the main challenges we face, as warm temperatures and high humidity promote the growth and expansion of insect populations. To keep pests in check, it is important to consider all our options. If we turn too quickly to chemical controls, we will often encounter insecticidal resistance over time and our beneficial insect populations will be negatively affected.
One alternative to chemical controls to help combat destruction of our crops is by planting trap crops. Trap crops are plants you grow that the insect pest prefers for food and egg laying over the crops you grow that you plan to harvest. These trap crops attract harmful insects, luring them away from your garden veggies.
Sunflowers can attract leaf-footed bugs away from tomatoes. Hand pick and squish any that you see for better control. Photo by Molly Jameson.
One effective trap crop example, which has proven effective in research studies, is using the combination of sorghum and sunflowers to lure leaf-footed bugs away from your tomatoes. If left unchecked, large clusters of leaf-footed bugs will feed and mate on developing tomato fruit, leaving your tomatoes discolored and distasteful. For tomato growers, it is worth the effort to plant both sorghum and sunflowers about two weeks ahead of your tomato crop. The blooming heads of the sunflowers will lure the leaf-footed bugs in. Hand pick and squish both adults and nymphs off of the sunflowers to help cut back on their populations. As the sunflowers die back, sorghum heads start to emerge, giving you enough time to harvest your tomatoes while the leaf-footed bugs feed on the sorghum panicles.
Another effective trap crop example is to grow blue Hubbard squash at least two weeks ahead of cucurbit crops, such as zucchini, summer squash, or cucumbers. The blue Hubbard squash acts as the trap crop, luring cucumber beetles, squash bugs, and squash vine borers away from the crop.
Buckwheat flowers attract pollinators and predatory insects into the garden. Photo by Janis Piotrowski.
Trap crops are also a great tool for drawing in pollinators and natural predators of insect pests into your garden. For example, sweet alyssum and buckwheat flowers attract wasps and hoverflies. The wasps will lay their eggs on caterpillar pests, and when the eggs hatch, the wasp larvae eat the caterpillars as they mature. Hoverflies will lay their eggs on the leaves of the trap crops, which will hatch and feed on mealy bugs and aphids. Additionally, bees will be attracted to the trap crop flowers, introducing more and more pollinators into your garden.
When it comes to being a successful gardener, it is important to have an integrated approach. When cultural and preventative gardening techniques are combined with biological control techniques, such as trap cropping, your garden will be more resilient to pests and diseases, and you will be less reliant on chemical control methods, which should be seen as a last resort.
by Matt Lollar | Feb 24, 2022
We often think of plant pests to be only insects. However, plant pests can also be fungal and bacterial diseases, weeds, and even rodents. That’s right, rodents, like squirrels, mice, and rats! One particularly annoying rodent pest of the garden is the roof rat (Rattus rattus, a.k.a. citrus rat, fruit rat, black rat, or gray rat). Roof rats are native to southern Asia. This is the same species that was responsible for carrying the bubonic plague around the world. Roof rats are the most detrimental rodent pest to fruit crops in the state of Florida. In addition to fruit crops, they feed on stored animal and human food. Roof rats live in attics, soffits, walls, and outbuildings. They also chew through wires, pipes, and walls. Roof rats damage some fruit crops (like citrus and melons) by first creating a half dollar sized hole, then they hollow out the fruit. In crops without a rind or peel, like peaches and tomatoes, they just eat large chunks.
Roof rat damage to tangerines. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Adult roof rats are 12-14 inches long with tails longer than their body length. In Florida they have been identified in three color phases: black back with gray belly; gray back with light gray belly; and brownish gray back with a white or cream colored belly. Other than fruit damage, evidence of infestation includes 1/4-1/2 inch long droppings and rub marks left along travel trails. Roof rats will travel up to 150 yards from their den for food and water. They breed year-round and have litters of 5-8 pups with a gestation period of only 21 to 23 days.
An adult roof rat. Photo Credit: Alabama Cooperative Extension System
A well-thought-out integrated pest management strategy is needed to control and potentially prevent roof rats on your property. Integrated pest management is a strategy consisting of multiple tactics to control a pest. These tactics include scouting (looking for evidence of the pest population); prevention; trapping and exclusion; biological control such as predators; and rodenticides and repellants.
- Prevention – Roof rats are good climbers and swimmers. It is important that fruit trees are planted away from the house, fences, and outbuildings. Make sure to prune fruit trees away from these structures if they can’t be removed or transplanted to another location. Also prune branches from touching the ground to help prevent rats from using trees for cover. Sheet metal (18-24 inches wide) can be loosely wrapped around the tree trunk to keep rats out of the tree.
- Trapping – Rat traps can be placed in several strategic locations. Traps (triggers facing down) can be attached to the trunks of trees. Traps can also be attached to the stringer boards on a fence. Make sure that traps are only set from dusk to dawn to avoid killing non-target species like birds and squirrels. Leave traps in place for at least a week before moving them because roof rats are cautious of new objects.
- Rodenticides & Repellants – Poisons should only be used after all other control methods are exhausted. Most products are very toxic to humans, pets, and wildlife. If used outdoors, poison baits must be placed in tamper-resistant bait stations.
- Biological Control – Rat snakes and king snakes are good natural predators for roof rats. If you have more open spaces you may consider building a barn owl house. Barn owls and hawks are also natural predators. You may also consider getting a farm cat to help control the population. Cats will kill juvenile rats, but have trouble catching adult rats.
Hopefully you will never have to encounter roof rats or other rodents invading your yard and house. However, if they do come around more information is available in the publication “Pests in and Around the Southern Home“.
by Molly Jameson | Oct 28, 2021
As you garden this fall, check out the North Florida Vegetable Gardening Guide, compiled by UF/IFAS Leon County Extension.
Getting into vegetable gardening, but don’t know where to start?
Even experienced gardeners know there’s always more to learn. To help both beginners and advanced gardeners find answers to their questions, the UF/IFAS Leon County Extension Office put together the North Florida Vegetable Gardening Guide. It incorporates multiple resources, including articles, planting calendars, photos, and UF/IFAS EDIS publications.
The North Florida Vegetable Gardening Guide covers the many aspects of vegetable gardening, including how to get started, site selection, insects and biodiversity in the garden, soil testing, composting, cover crops in the garden, irrigation, and more.
You can click here to view the digital version of the guidebook. We also have physical copies of the guide available at the UF/IFAS Leon County Extension Office (615 Paul Russell Rd., Tallahassee, FL 32301).
Happy fall gardening!
by Evan Anderson | Oct 21, 2021
While most people are familiar with the European honey bee, the domesticated insect that pollinates our crops and provides us with honey, there are plenty of other species of bees and their relatives out there. Most of them are harmless, spending their time quietly pollinating plants, including our crops. Their presence in the landscape, however, may cause some alarm, as it can be difficult for the untrained eye to distinguish between aggressive species and those that are innocuous.
The entrance to a miner bee burrow.
Homeowners may occasionally note small mounds of soil in sandy areas of their lawns. Sometimes sporting a small hole in the center, these are the nesting sites of solitary, ground-nesting bees or hornets. Miner bees or digger bees build underground chambers, usually in well-drained, otherwise bare areas of sandy soil. Multiple bees may choose to dig their nests in the same location, though each bee makes its own tunnel and they do not live communally. Each bee lays her eggs in the nest she has excavated. She gathers pollen to feed the young when they hatch, stocks the larder, and leaves. When the young emerge from the nest, they fly away and do not remain; they will dig their own nests when they are ready to reproduce. While there is no need to control these insects (they serve as fantastic pollinators), the mounds of soil they make may be aesthetically displeasing to some people. Keeping a healthy lawn with no bare patches can deter miner bees from nesting in an area. Irrigation sprinklers can also help to keep the ground moist; these bees prefer dry soil, so it may keep them away. Care must be taken not to over-water a lawn, however!
A cicada killer wasp. Photo credit: Division of Plant Industry
Another species of note is the cicada killer hornet. Also known as the giant ground hornet, these insects grow to a size of about an inch and a half in length. Instead of pollen, they capture cicadas to feed their young. Like the miner bee, though, they are not harmful. Females do possess a stinger which they use to hunt their prey. Males may try to warn people or animals away from their burrows by acting aggressive, but they have no stingers. Some may see the large size of the cicada killer and wonder if the so-called “murder hornet” has made its way from Washington state to Florida, but as of this writing it has not. Unless you are a cicada, you have nothing to fear.
One ground-dwelling hornet that does warrant some concern is the yellowjacket. These are communal hornets, living in hives that are often build underground. Yellowjackets are known for their bad attitudes, attacking anyone who disturbs the entrance to their nest. They can be beneficial, being predators of many other insects including plant pests. A colony located too close to human dwellings or areas of activity is most often a nuisance, however. Any attempts to control yellowjacket nests should be done at night when they are less active. Protective clothing is recommended even then. Large or difficult to reach nests may require the attention of a certified pest control company.
For more information on these topics, see our EDIS publications:
Miner Bees: https://edis.ifas.ufl.edu/publication/in912
Cicada Killers: https://edis.ifas.ufl.edu/publication/in573
Yellowjackets: https://edis.ifas.ufl.edu/publication/IN238
by Ray Bodrey | Oct 14, 2021
Tree dieback is a complex syndrome and slow developing. Dieback is essentially a process in which trees lose leaves and limbs. This usually occurs as a result of severe stress to the tree’s bark or root system, but could be a result of a declining life cycle.
It’s important to note that there is a significant balance between a tree’s root system and the number of leaves and limbs it can support. For example, if a tree loses part of its root system, possibly due to disease or lawn equipment damage, the tree will forfeit a portion of its leaves. Dieback doesn’t happen overnight, though. It’s a slow process, with larger trees taking much longer time for signs of stress to emerge. However, a large tree root system is very sensitive to damage, whereas a small tree will adapt quickly and is much more resilient to damage. So, what can be done to prevent dieback in trees?
First and foremost, trees, like all living things, have a natural life cycle. Regardless of how you care for your trees, dieback will occur. The most important management measure in extending the life of a tree is to protect the root system and bark.
With each passing year, a tree grows new bark in the rejuvenation process. The bark replacement process inevitably becomes more difficult as the tree gets older and in turn the tree is more and more susceptible to dieback. If the bark becomes damaged, especially later in the tree’s life cycle, then fungi and insects have a much greater chance to cause serious harm. Treating bark damage with a wound dressing to prevent decay is the recommended procedure.
Lichens come in many forms and are commonly blamed for the decline and death of trees and shrubs, however they do not cause harm. Credit. Sydney Park Brown and Joseph Sewards, UF/IFAS.
A common misconception is that epiphytes, such as lichens and Spanish moss, are tree diseases. Epiphytes are known as “air plants” and thrive in the Panhandle. They survive on moisture and nutrients in the atmosphere and are harmless to trees. However, a tree that becomes inundated with epiphytes may be an indicator of excessive soil moisture, which may lead to root rot.
Lawn weed killers can have detrimental effects to trees, even if the application seems to be from a safe distance. When using a weed killer near a tree’s root system, confirm on the label that the product is designed to kill green growth only. It can’t be overstated that excessively fertilizing an old tree will greatly accelerate the decline of the tree. Some may think this will stimulate a tree and extend its life, but instead it will do the opposite. Young trees can tolerate fertilizer applications, as they need crown growth. Older trees will simply become top heavy, and structural damage will likely occur.
Don’t forget, trees need space too. A mature tree forced to occupy a small space will simply not adapt. Be sure to have adequate spacing when planting younger trees and shrubs in the vicinity of older trees. Also, keep your trees pruned away from touching structures and utilities.
Tree dieback is a complex issue to manage. By following these measures, you can help extend the life of your trees and continue to have a picturesque landscape.
For more information on tree dieback, contact your local county extension office.
Please visit Florida Friendly Landscaping, http://fyn.ifas.ufl.edu/, for more information on maintaining your landscape.
For more general information on lichens, please see UF/IFAS EDIS document “Spanish Moss, Ball Moss and Lichens-Harmless Epiphytes” by Joe Sewards and Dr. Sydney Park Brown: https://edis.ifas.ufl.edu/pdffiles/EP/EP48500.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
