A female striped lynx spider protects her egg sac. Photo credit: Carrie Stevenson, UF IFAS Extension
With Halloween just behind us, some of us may still have fake spiders in our yards and cotton webbing all over the shrubbery. Spiders (along with bats) are among those creatures feared and demonized in folklore this time of year. It is important to remember, however, that both organisms are important predators and managers of our insect population.
Last week during a walk on the Extension property, I came across a large brown spider hovering protectively near her egg sac. Perched in a newly planted pine tree, I saw no obvious web. Instead, the spider loosely wrapped the pine’s needles with silk, forming a support structure for the relatively large egg sac.
Newly hatched striped lynx spiderlings on silk scaffolding covering a plant. Photograph by Laurel Lietzenmayer, University of Florida.
On further research, I learned that this female striped lynx spider (Oxyopes salticus) would have mated just once, after responding to a male’s courtship display (involving drumming and elaborate leg touches). She would have produced the egg sac 1-4 weeks after mating, attaching it to the pine needles, and will tend to it until her young emerge 20 days later. Up to five days after hatching, lynx spiderlings disperse by “ballooning” from the plant—they release a silk thread into the air, allowing the wind to carry them off like a tiny skydiver. Those spiderlings will mature into adults by 9 months, living their entire lifespan in just one year.
During that year, though, lynx spiders are important predators of pest insects. Instead of catching bugs in a web, they stalk their prey like a big cat—hence the name, “lynx.” They prey on many fly species, but also on bollworms and green stinkbugs that are major pests of cotton and soybean crops. These spiders are beneficial and highly vulnerable to insecticides.
An adult firefly showing off its characteristic beetle wings and bioluminescent abdomen. Credit: Art Farmer, Creative Commons.
Many of us have memories of warm summer nights watching fireflies. Some of us might have even chased and caught a few to put in mason jars for observation, fascinated by their glowing abdomens. Floridians have the best chance to see these unique insects, as we have more known species than any other state. Recently, I’ve had many folks say that they see less fireflies these days, which got me looking into how these creatures live and what researchers know about their numbers.
Fireflies are actually a type of beetle in the Lampyridae family. They go through complete metamorphosis, meaning their immature larvae look completely different than the adults. A very unique characteristic of the family is the ability to produce light, known as bioluminescence. They do this in a very efficient way, creating very little heat, through the reaction of luciferin and luciferase along with oxygen, some energy, and other compounds. These light-producing compounds serve a dual purpose, warding off predators and attracting mates. The larvae of all Lampyridae benefit from the offensive taste of the compounds while only some adult Lampyridae use bioluminescence to attract mates. Each species of firefly has specific patterns of flashes. Males have the showiest light displays while females use more conservative light shows to signal back to potential mates.
Firefly larvae taste bad to predators due to the compounds that produce light. Credit: Gerald J Lenhard, LSU, bugwood.org.
Larvae of fireflies live in the soil and feed on slugs, snails, earthworms, and other soft-bodied insects. The larvae develop in the soil during cooler months, preferring moist habitats, and emerge as adults in the late spring to early summer. Some species may emerge in the early spring. Adult fireflies feed on nectar and honeydew, though some females prey on smaller firefly species by fooling males close to them through light signaling. Adults with the ability to produce light are active at night, while non-bioluminescent adults are active during the day.
An adult firefly. Credit: Mirko Schoenitz, iNaturalist.org.
Entomologists specializing in fireflies have raised the concern that these classic summer-time insects are in decline. Reasons for the decline are associated with increased urbanization. Loss of suitable habitat and increased pesticide use, including broad-spectrum insecticides for home lawn insect control, negatively affect firefly larvae living in the soil. Researchers also point to urban light pollution as another cause. The ever-glowing night sky in populated areas, originating from house lights, ball fields, parking lots, and roadways, disturb firefly communication and reproduction.
UF/IFAS infographic about fireflies. Credit: UF/IFAS.
Homeowners can help fireflies by leaving small patches of unmanaged landscaped areas, such as along property lines, and only using insecticides when absolutely necessary. If pesticides are needed to control lawn and garden pests, the use of more selective, low-toxicity products is preferable. Turning off unnecessary outdoor lighting is another step homeowners can take to encourage firefly populations. Residents of homeowner associations can work together to minimize excess lighting community-wide, saving electricity and maybe even fireflies.
For more information on fireflies and best practices to control lawn and garden pests, contact your local county extension office.
Wildflowers near Live Oak, Florida. Image Credit, UF / IFAS
Florida (“land of flowers” in Spanish) is and has always been full of flowers, and countless civic and public organizations work diligently to protect and promote the beauty of our natural ecosystems. Did you know that the Florida Wildflower Foundation works with the Florida Department of Transportation (FDOT) to preserve wildflower areas on state-maintained roads throughout Florida? This effort really took off in the 1960’s when non-native Crimson clover started sprouting among sod planted by the state FDOT, and has grown into a much larger statewide initiative. The state wildflower license plate program provides funding for these efforts.
Wildflower areas along highways not only improve beauty on the roadsides, but provide habitat for countless pollinator insects that drive our $1.2 billion (annual) citrus and agricultural industries and our own backyard landscapes. In addition, leaving no-mow areas along highways saves money on mowing costs, reduces soil erosion, and improves air quality.
The state wildflower license plate supports wildflower preservation efforts statewide. Photo credit: Florida Wildflower Foundation
Wildflower viewing is typically best in the spring and fall, and particularly in areas (such as state parks and forests) that have been recently managed by prescribed fire. Many low-lying areas are home to beautiful native species such as pitcher plants, hibiscus, and meadowbeauty. Be very careful when viewing or stopping to see roadside wildflowers, and be sure to find designated parking areas to prevent accidents. To find a map of the wildflower trails, visit your local tourism bureau or go online at https://flawildflowers.org/protect/.
Currently, every Panhandle county from Jefferson County east has designated wildflower areas. The Escambia County Board of Commissioners passed a wildflower ordinance supporting the program, and a committee met in May 2019 to determine more areas of the county appropriate to set aside for the program. As opposed to planting new wildflowers, the program prioritizes conserving roadside areas that already support healthy wildflower populations. If you know of good candidates for preservation on state roads in Escambia or any other panhandle county, please contact me (ctsteven@ufl.edu) or Liz Sparks (liz.aparks57@gmail.com) with the Florida Wildflower Foundation.
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.
One of the incredible benefits of living in Florida is exposure to the biodiversity of our wildlife population. From ordinary squirrels and mockingbirds to the more exotic panthers and migratory tropical birds, it is rare one can step outside the house without seeing or hearing wildlife of some variety. One of the practices we “preach” here at Extension is to provide habitat for wildlife in our yards and gardens. While cities and neighborhoods are human-centric, we share these spaces with thousands of wild animals, birds, fish, and insects and should always consider them in our actions.
Attracting birds and butterflies are popular pastimes, and Extension faculty can provide a tremendous amount of information on their preferences and food sources. However, a few unsung critters deserve homes and space as well. Just yesterday, I took a call from a gentleman who was excited to discover a small colony of bats roosting in a tree on his property. He was looking for ways to encourage them to stay, because he realized the countless benefits they provide in free insect control. Many people are nervous around bats of because of their unpredictable, irregular night flight pattern and association with scary stories. However, an average Florida bat can eat 1,000 insects a night, keeping pest populations down, reducing mosquito-borne disease, and saving millions of dollars in crop damage.
In our demonstration garden today, I was delighted to walk up on a black racer sunning itself in the grass. These common garden snakes provide valuable pest control of rats and mice, and are not aggressive or venomous. The fear of snakes often comes from the surprise of finding one unexpectedly, so always be alert and observant when outdoors. Respect for these creatures and a basic working knowledge of common venomous and nonvenomous species can go a long way towards calming one’s nerves. An excellent resource for snake identification in north Florida is this online guide. Like many snakes, this particular snake had been in tall grass, so it is always wise to be cautious in those areas.
This black racer sunning in the grass must have gotten the message about utilizing habitat provided for wildlife! Photo credit: Carrie Stevenson, UF IFAS Extension
To attract wildlife, learn about their life cycle and food sources, and provide shelter, water, and food for the species you are interested in attracting. Keep in mind that inviting wildlife may also draw their predators, but know that this is part of the larger cycle. Always keep safety in mind, and if necessary keep tall vegetation and deep water to a minimum in play areas frequented by young children. The benefits of providing food and shelter for wildlife are countless for human observers and wildlife alike.
Many gardeners plant a spring vegetable garden with a number of different vegetable types, which is excellent because a diverse and varied garden is proven to improve soil health. Intercropping is a gardening practice of growing different crops in the same field. When planting a mixture of crops in the same field year after year, it is important to rotate the location of each type of vegetable. This is a practice known as crop rotation. Intercropping and crop rotation will help reduce insect pest populations, increase beneficial insect populations, and reduce weed populations .
Crop Diversity
Including plants that pest insects don’t like to eat in a garden forces the pests work harder to find what they find palatable. Studies have found reduced whitefly numbers on squash plantings mixed with a crop of buckwheat when compared to squash planted alone. Another crop mixture that may be unintentional, but may be favorable, is a crapemyrtle stand along a garden’s edge. Crapemyrtles will attract the crapemyrtle aphid which will attract predatory insects. When the predatory insects run out of crapemyrtle aphids to eat, they will move to the vegetable garden and begin to hunt pest insects.
Squash with living mulch of buckwheat. Photo Credit: Oscar Liburd, UF/IFAS Extension
Trap Cropping
A trap crop is a plant that attracts a pest insect away from your food crops. Trap crops work best when planted at the garden’s edge, along a fence row, or in movable containers. A bare space, let’s say 5 feet or so, should be kept between trap crops and vegetable plantings. This will help keep the pests from moving desirable crops plants. When a large population of pests are found on the trap crop then it is time to spray them with insecticide, or cut the crop down and remove or destroy the debris. If trap crops are planted in containers, then it makes them much easier to remove from the garden when necessary.
Cover Crops and Green Manure
Soil organic matter can be increased by the use of green manure and cover crops. Cover crops are generally planted during the off-season, but they can be planted in between vegetable rows and tilled in at a designated time as a green manure. Both cover crops and green manure improve garden production by:
Suppressing weeds by competing for water, light, and nutrients;
Holding the soil in place and preventing erosion;
Scavenging for nutrients that can be utilized in future crops;
Reducing nematode populations;
Providing a habitat for beneficial insects.
A mixed plot of cover crops and trap crops. Photo Credit: Matt Lollar, UF/IFAS Extension – Santa Rosa County
A number of different crops can serve as cover crops or green manure crops. Most are legumes (bean family) or grasses. A few that should be tried are:
