Not all fall color is a good thing. This statement is especially true when it comes to twig pruners and twig girdlers. These two species of longhorned beetles can certainly disappoint your grand expectations of a beautiful array of fall color. Both species cause the tips of twigs to fall to the ground in late summer, sometimes leaving your trees in an undesirable form.
Twig Pruners
The twig pruner (Elaphidionoides villosus or Anelaphus villosus) is a small longhorned beetle that attacks numerous species of hardwoods. It is usually classified as a secondary pest of declining trees and shrubs. Female twig pruners lay their eggs in late spring at the leaf axils. When the eggs hatch, the grubs bore into twigs and continue to bore as they mature. The larvae then chew concentric rings just underneath the bark. The infested twigs and branches eventually drop to the ground with the larvae inside. The larvae pupate inside the fallen twig throughout the winter.
An adult twig pruner. Photo Credit: University of Georgia
Twig Girdlers
The twig girdler (Oncideres cingulata) is a small longhorned beetle that invades many species of hardwoods. Female twig girdlers lay their eggs in late summer in small twigs (about 3/8 inch diameter) that are covered with a thin layer of bark. The female chews a concentric ring around the outside of the twig, causing the end of the twig to die. The female chews a small notch in the dead twig and lays her eggs. After the eggs hatch, the larvae feed on the dead twigs and develop into adults before chewing their way out. The adults fly away to new host trees.
An adult twig girdler. Photo Credit: Lacy L. Hyche, Auburn University
Management and Control
It’s important to plant the right plant in the right place. Healthy trees and shrubs are the best defense against insect pests. Twig pruners and twig girdlers live in dying or dead twigs and branches. If you have trees that have suffered damage from these pests you will notice an abundance of fallen twig ends around the base of your trees. Rake and remove fallen twigs from around the trees and destroy or dispose them. This will help reduce pruner and girdler numbers in subsequent years.
A mole cricket has a face only a mother could love. They are so strange looking, in fact, that in the past week I’ve had two people ask me what they were. They have large, round, helmet-like heads, undersized eyes, and massive front claws used for digging. Unlike your garden-variety crickets, which really don’t cause any major damage to home landscapes, the mole cricket is quite the turfgrass menace. Instead of hopping about aboveground, they tunnel beneath the lawn and feast on the roots and leaves of grass, often destroying entire yards. They are also vegetable pests, going after tomatoes, cabbage, and peppers.
A young mole cricket. Its round head and large front claws distinguish it from other cricket species. Photo credit: Lucy Adams StevensonA) Horizontal and B) vertical view of a generalized tawny mole cricket burrow showing 1) horn, 2) 1st constriction, 3) bulb, 4) 2nd constriction, 5) turn-around, 6) surface tunnel, and 7) deep tunnel. Figure 1 from Nickerson et al. 1979. Ann. Entomol. Soc. Am. 72(3):438-440.
Mole crickets spend most of their time below ground and form burrows for hiding, laying eggs, and traversing through their territory. In mating season, males create a monotone song that averages 88 decibels—as loud as a motorcycle! The call comes from their burrows, which have funnel-like openings that expand at the surface, creating amplification comparable to a horn.
Beneficial larra wasp parasitizing a tawny mole cricket. Photo credit: UF IFAS
The tawny mole cricket (Neoscapteriscus vicinus) is the most common to our area and is an invasive species from South America. UF IFAS has had a specific research program related to mole cricket management since the late 1970’s. One successful outcome of this program has been the introduction of a biological control species, the larra wasp (Larra bicolor). The wasp manages mole cricket populations by stinging and temporarily paralyzing crickets. A female will then deposit an egg into the mole cricket’s body. The cricket recovers and goes about its daily routine until the egg hatches, at which point the larval wasp feeds on and eventually kills the mole cricket. Along with the wasp and release of flies and a nematode that also manage mole crickets, the biocontrol methods introduced between the 1980’s and 2004 have resulted in a 95% reduction in mole cricket populations in north Florida.
If you are seeing mole crickets, you can attract larra wasps to your property by planting shrubby false buttonweed or partridge pea plants, which the wasps feed on. If you have serious damage from mole crickets, check out this thorough Mole Cricket Integrated Pest Management Guide, or contact the horticulture agent at your local county extension office to get a site-specific recommendation for management.
In the heat of the summer biting flies become very active during the day. Deer flies, horse flies, and especially yellow flies inflict a fierce bite on people and other animals. All three species are in the Tabanidae family, commonly referred to as tabanids. Like mosquitoes, female flies of these species require mammalian blood in order to gain the enzymes necessary to lay eggs.
The tabanids lie in wait under bushes and in trees until a host is sensed. The keen eyes of the flies are able to see their prey’s movement, but mammals also create scents and carbon dioxide, making them very easy to locate. The attacks begin at sunrise, lasts about three hours, fades through the heat of the day, and peaks again about two hours before sunset, lasting until the sun goes down.
Tabanids use their mandibles to cut through the skin like scissors, causing blood to flow. Anticoagulants in the fly saliva are pumped into the wound to keep the fluid coming while the insect sponges it up with its labella.
While blood loss and disease transmission are concerns, for most, the disturbing part of the attack is the painful bite! Many people experience other adverse effects that extend the agony.
So, what can you do? The use of insecticides is generally considered ineffective and/or economically unfeasible. Habitat manipulation is an important component to reducing populations. Tabanid eggs are laid in layers on vertical surfaces, especially on aquatic vegetation. Secretions from the adult fly protect the eggs from water damage. When the maggots hatch in 5 to 7 days they must remain in moist areas to survive.
Over the next few months, larvae feed on organic matter, crustaceans, earthworm, and insect larvae (including their own species), steadily growing larger. Once fully grown, the larvae move close to the soil surface to pupate. Within 2 days the process is complete. They will remain in the pupal stage for 2 to 3 weeks before emerging as an adult fly.
So, reducing breeding habitat in areas where people and animals spend their time is a possible management technique.
For those times when you want to be at these sites, a trap may help. Research has shown that blue cylinders (open side toward the ground) coated with sticky material and attached to slow-moving objects are effective at reducing the abundance of these flies.
So, get out the Tanglefoot™, spread it on a blue plastic cup, and hang it from a branch that’s moving with the wind. How about attaching one to the boat, tractor, or lawn mower?
If your personal image is less important than the pain of the bites, you may even consider putting the cup on your hat.
When you hear the word “pollinator”, what is the first insect that comes to mind? If I had to guess, you would probably say honey bee. European honey bees play an important role in agriculture as pollinators and honey producers, but there are hundreds of native pollinators often overshadowed by the beloved honey bee you should know about, too!
One such group of pollinators native to Florida are sweat bees. Sweat bees get their unfortunate name from their nutritional requirements of salt that are sometimes sourced from sweaty humans. They rarely sting but are capable, and they can certainly be annoying to people when they lick salt off their skin. This behavior tends to get more attention than their important role as pollinators.
A subgroup of sweat bees are furrow bees. Furrow bees nest in the ground or rotting wood and may be solitary or eusocial. In-ground nests are composed of branching tunnels in sandy soil at a depth between 8 inches and 3 feet with a small entry roughly the size of a pencil. Within the tunnels, the mother creates individual cells stocked with nectar and pollen and lays an egg. The larva feeds on these provisions and pupates underground eventually emerging as an adult. The life cycle can vary from a few weeks to a year or more depending on species and environmental conditions.
Furrow bees are generalist feeders which means they will visit many different flowers, so diverse landscapes are attractive to them. In my northwest Florida garden, I see them often on sunflowers, Black-eyed Susan, coneflower, cosmos, tithonia, zinnia, and tickseed.
Poey’s Furrow Bee is a common visitor to sunflowers. J_McConnell, UF/IFAS
Unknowingly we interact with many small creatures in our everyday lives. Spiders are one of these groups that are beneficial to the function of human activity. This group receives much publicity as being dangerous to people and our pets. While there is always a possibility of being bitten and having venom injected by a few types of spiders, most all others are harmless to people. The primary benefit of spiders is their propensity for catching insects outside and in the home that are identified as harmful to people. Spiders come in all shapes and sizes with many hiding away, never to be seen by people.
Spiders are often included in the same group as insects, but this is not true. They belong in the group arachnids and are closely related to ticks, scorpions and mites. Spiders have two body sections (cephlothorax and abdomen) and have eight legs while insects have three body sections (head, thorax and abdomen). Scorpions usually remain outdoors and may be found indoors during hot dry periods. They are nocturnal hunters of pests that include roaches. None of the scorpions native to Florida are capable of providing a lethal sting, but it is painful when it occurs, leaving a sore and swollen at the sting area. I was reminded of this after stepping on one in the late evening while moving around the kitchen with no lights on. If the person that is stung has allergic reactions to bee stings, observe them and take precautionary health measures needed.
The spider is an important predator of harmful insects and can be found about any where in and around the home, in the garden, and many other places in the great outdoors. An Extension Entomologist I knew from North Carolina State University always mentioned, when presenting to Master Gardener Volunteer classes, that at almost any time given time, we are within two to three feet of a spider, with most so small we never see them. They are great at keeping the beneficial and harmful insect populations in balance in nature.
If you decide to spray to manage your spider population, keep in mind that by reducing the number of spiders in the landscape, you can create a reverse problem with harmful insect populations increasing dramatically. If big webs are a bother, simply take a broom and knock them down. They will rebuild by the next day, but you may not need to be in that area for a while. Always be careful and wear gloves when working in the garden, especially areas that are dark and covered, such as irrigation valve boxes, wood stacks, and other similar places. These are prime locations where the Black Widow or Recluse spiders may be set up, waiting to ambush roaches and other insects. If you are bitten by either seek immediate medical care.
Finally, spiders are fun to observe in nature! One of the most interesting spiders to watch is observable during fall in Florida – the Yellow Garden Spider. They build large webs and often place a zig zap signature in the middle. This large spider catches many insects in the garden and landscape. With early morning sunlight and dew hanging on the web during the fall, it makes for a beautifully create piece of art. Enjoy nature and all the creative processes that occur from a safe distance – spiders included!
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.
