Insects use pheromones to attract their mates and communicate with each other. Ants use pheromones to tell fellow ants where to find food. Aphids use pheromones to warn each other about potential predators. And all insects use pheromones to call for a mate.
So what exactly are pheromones? Pheromones are substances that are secreted by an individual and received by another individual of the same species. In humans, pheromones are most commonly found in sweat and detected by the olfactory system. Most animals have a functioning vomeronasal organ inside their noses to detect and process pheromones. However, it is debatable whether adult humans possess a functional vomeronasal organ.
Although most of us may not be able to detect insect pheromones, scientists have been able to identify and synthesize the pheromones of many economically important insects. These pheromones are impregnated on rubber and plastic dispensers and placed in different types of traps depending on the pest. The pheromone traps attract males of the target species. These traps are commonly used for monitoring, but in some cases can be utilized to disrupt mating habits which can help control some pests.
The most common pheromone trap in this part of the country is probably a boll weevil trap. Growing up, I thought they looked like little green lighthouses. These traps consist of a yellow-green cannister with an inverted funnel on top that contains the pheromone. While you may not be growing cotton in your home garden, there are some other common insect pests you may want to monitor and possibly disrupt.
Pecan nut casebearer trap with pheromone bait. Photo Credit: UGA Cooperative Extension
Pecan Nut Casebearer (PNC) – These moths are gray with a dark line of scales on their forewings. PNC moths are about 1/3 inches long. They lay their eggs on the outside of pecan husks in April/early May. Their larvae bore into the base of developing nuts and remain inside the nuts for four to five weeks to feed then pupate. A tent-type trap with pheromone can be hung in a pecan tree in April or May to help monitor for this insect. Depending on how many trees you have, multiple traps can be installed to possibly disrupt the mating cycle of this pest.
A yellow sticky trap with Asian citrus psyllids circled. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Asian Citrus Psyllid (ACP) – These tiny insects are about the size of the tip of a pencil (about 1/8 inches long). They vector the Huanglongbing (HLB) disease also known as citrus greening. This disease blocks the nutrient uptake tissue of citrus trees and eventually kills infected trees. Traps consist of a yellow sticky card with a pheromone bait sometimes impregnated on the twist tie hanger. The citrus industry has been heavily impacted by citrus greening, so monitoring for this pest is very important.
An abundance of clearwing moths on a pheromone trap that has been pulled apart. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Clearwing Moth – There are numerous species of clearwing moths that bore into the trunks of fruit and ornamental trees and shrubs. One of the most common is the peachtree borer. These insects don’t look like a typical moth. Instead, they resemble wasps. Tent-type pheromone traps can be used to monitor for clearwing moths and potentially disrupt their mating habits. Another common clearwing moth is the ash borer (lilac borer). As their name would suggest, these moths bore into the wood of ash trees, but they also like various Ligustrum species and olive trees.
These are just a few of the species of insects that can be monitored by pheromone traps. To help with the timing of trap dispersal and placement, you should get a grasp of concept of “Degree Days”. Degree day accumulation is used to predict important life events for particular insects such as the average egg laying date, egg hatch date, and larval development. More information on calculating degree days can be found in the article “Predicting Insect Development Using Degree Days” from the University of Kentucky. Fortunately for us, we can skip some of the math by utilizing the AgroClimate Growing Degree Days Calculator. Simply select the weather station closest to you on the provided map and a graph will appear.
Every spring, a certain type of pollinator is busy in the yards and landscapes of our area. It may be alarming to see small piles of soil mounded up amidst carefully tended grass, but there is no need for concern. In fact, quite the opposite! The creatures making those mounds are bees, but they’re not the type that want to sting you. Instead, they’re harmless, solitary pollinators who just want a safe place to lay their eggs.
Miner bee burrows. Photo Credit: University of Florida/IFAS
It’s easy to confuse a bee digging in the lawn or landscape for a yellowjacket and become alarmed. Yellowjackets are very different; they form hives underground consisting of hundreds or even thousands of individual hornets. Miner bees, on the other hand, each dig their own small burrow. Each miner bee is looking for the same sort of place to build a little hidey hole, so many individuals might be attracted to an area with prime real estate, so to speak. This can lead to large numbers of mounds in close proximity to one another, but again, there is no reason to be alarmed.
A miner bee. Photo Credit: University of Florida/IFAS
Each female bee will dig a vertical tunnel up to a foot and a half deep, then make side chambers lined with waterproof material. She stocks each chamber with pollen and nectar, then lays her eggs. Larvae remain in the ground until the following spring. When they emerge as adults, they start the whole process over again.
It is important to understand and protect pollinators such as the miner bee, because they all provide a valuable service to the environment. Pollinators ensure that all the plants around us can reproduce, by carrying genetic material from one flower to another. You can help these little messengers in their task by learning about their habits and making a little room for them in your landscape. When you see these small mounds of soil in your yard, don’t worry! The bees will do their job and the next rain will likely wash away the soil.
Consider attracting other pollinators as well! Plant flowers that attract native pollinators, or leave an area of your landscape “wild”. Let dead plant stalks remain over the winter as nesting sites for pollinators, or try letting a patch of native wildflowers escape mowing for some time in the spring.
For more information, there are plenty of publications out there:
If you’ve been raking leaves recently, you’ve probably noticed little green worms hanging from the trees. They seem to be in abundance this year and can be found crawling on driveways, just hanging around, and maybe even feeding on oak tree leaves.
These green worms that are all over the yard are oak leafrollers (Archips semiferanus) or oak leaftiers (Croesia semipurpurana). Some people may refer to them as inchworms, however a number of different caterpillars can go by that name. Leafrollers and leaftiers range in length from 1/4″ to 1″. The adult form of these insects is a 1/2″ long moth. The oak leafroller moth is mottled tan and brown and the oak leaftier moth is yellow with brown markings.
An oak leafroller caterpillar crawling on a leaf. Photo Credit: Blair Fannin, Texas A&M University
In May, the adults of both species lay their eggs in the twigs and leaf buds of a number of tree species. The eggs don’t hatch until March of the following year. When the caterpillars emerge, they feed on the newly forming leaves and flowers of oak, hackberry, pecan and walnut trees. If they are disturbed, they will stop feeding and hang from a strand of silk. Oak leafroller caterpillars pupate in tree branches, while oak leaftier caterpillars drop to the ground and pupate in leaf litter. Adult moths emerge in one to two weeks.
A leafroller moth with wings spread. Photo Credit: U.S. National Museum
The oak leafrollers and oak leaftiers don’t really do enough damage to be considered pests, but they are a bit of a nuisance. Thankfully, birds and parasitic wasps will eat and kill the majority of the population. For in-depth information on most of the interesting insects in your yard, please visit the UF/IFAS Featured Creatures Website.
What’s eating my lawn? Does your grass look ragged in areas, as if someone randomly used a weed-eater here and there? Are you noticing brown patches that have a closely clipped appearance compared to other areas of your lawn? Your turf may be playing host to Tropical Sod Webworm.
Sod webworm damage in a home lawn. Photo courtesy UF/IFAS.
Sod webworm damage is subtle at first. You have to look closely to notice larval feeding damage. However, an easy indication of their presence is the light tan/brown colored moths, which are the adult stage of the pest. You may see them fly up as you walk through your lawn or if you disturb a nearby bush. The moths do not cause any damage to the turf, but they are depositing eggs, which will result in their offspring, the caterpillars, who do all the chewing damage.
The larvae are gray-green and have spots on each segment. The mature larvae can be up to 1 inch in length. Larvae will curl up in the soil during the day and feed at night. So if you happen to notice caterpillars feeding during the day, it’s probably not sod webworm. You will notice chewed notches along the leaf blade, holes in the leaf and even leaf blade skeletonizing. The older the larvae are, the more they will eat. Damage may start out as a ragged appearance in your turf, which can be hard to diagnose. However, if left unchecked, sod webworm can cause considerable injury to your lawn.
Sod webworm larvae. Photo courtesy UF/IFAS.
If you are uncertain of their presence you can always use a soap drench to flush out larvae. Mix 2 tablespoons of dish soap with 2 gallons of water and pour it over a damaged area (about 3 square ft.). The soap mixture will irritate the pest and bring them to the surface so you can easily identify them. If nothing appears in the area tested move to another damaged site and try again. Here is a link to a video that will give more information on identifying Tropical Sod Webworm.
Tropical Sod Webworm is considered a pest of all warm-season turfgrasses. However, St. Augustinegrass is most commonly affected. The best way to prevent a pest infestation is to use proper cultural maintenance practices for your lawn type. However, if the pest does appear, chemical control should be targeting the larvae stage of the pest. There are multiple products marketed to control lawn caterpillars. However, you may want to consider using B.t. (Bacillus thurengiensis), which is a bacterium that will only harm caterpillars and not bother beneficial insects that may be in your lawn. For more information you can contact your local extension office.
