A typical crane fly on the outside of a building. Photo credit: Carrie Stevenson, UF IFAS Extension
All my life, I’ve known them as mosquito hawks. Built like extra-large, spindly-legged versions of mosquitoes, they look a bit intimidating. However, growing up we were told they were harmless and actually fed solely on mosquitoes. In the days before Google, I just accepted it as fact and was glad to see them around.
In early March, there was a bit of an invasion of these insects. I started seeing them everywhere outdoors and inside my office building. They are slow movers, bouncing in the air more than flying. After several days of seeing them everywhere, though, they pretty much disappeared.
Several crane flies appear to have met their demise inside my office building. Photo credit: Carrie Stevenson, UF IFAS Extension
Like much folk wisdom accrued through my life, the story of the mosquito hawk is not totally true. They are harmless, that much is correct. While many people do know them as mosquito hawks, the accepted common name is the crane fly. Crane flies come in a wide variety of sizes and colors, ranging as some of the smallest and largest species in the fly Order, Diptera. Their diversity is rather mind-blowing, with the Family Tipulidae including about 15,000 species of crane flies worldwide.
Crane fly larvae live in aquatic environments and feed on decaying plant material. Photo credit: North Carolina State University
As for being voracious predators of mosquitoes, we have no such luck. Crane flies barely eat at all, because their adult life span is as short as those two weeks I recently noticed them around. They spend most of their lives as aquatic larvae, living in streams, pond edges, and rotting vegetation. Adults do not have the right mouth anatomy to eat other insect prey, instead drinking only by sponging up water in dew form or taking nectar from plants. Their primary purpose in adulthood is to complete the mating process. Females lay eggs near water, hence the location as larvae. After this hedonistic spring break experience of adult life, they die.
Crane flies, in both larval and adult forms, are popular snacks for other wildlife. The adults are easy targets for birds and bats. The larvae, which in some species are as large as a pinky finger, are tasty morsels for fish and amphibians. During their larval existence, crane flies ingest debris, helping with the decomposition process and filtering the water bodies they live in. Despite their short life span, crane flies make an outsized contribution to the food web.
Migratory animals are no stranger to our neck of the woods. Every year, Florida is host to countless creatures as they make their way from one place to another in search of food, nesting sites, or just a change of scene. From hummingbirds to manatees, it can be interesting to watch the annual cycle of nomadic animals.
A gulf frittilary butterfly.
One of the smaller wayfarers we see year-round, but especially when they migrate south in the fall, is the gulf frittilary butterfly, Agraulis vanillae Linnaeus. They spend the warmer months of the year in the southeastern United States, following frost-free weather as temperatures drop. During the winter, they enjoy the sunshine of peninsular Florida.
The gulf frittilary is a medium-sized butterfly, with a wingspan of 2½–3½ inches. Females are larger than males. It is bright orange in color, with black markings on the top of its wings and silvery-white spots on the bottoms. In its larval form, it is also bright orange in color, with dangerous-looking spines along the length of the caterpillar. Despite their appearance, these do not sting.
The gulf frittilary caterpillar looks dangerous, but won’t sting. Please do not eat it, however.
If given a choice its larvae will feed primarily on passionflower (Passiflora incarnataand related species), but have also been seen snacking on buttonsage. Toxins from passionflower concentrate in the larvae and butterflies, making them poisonous to predators – much like the monarch butterfly and its host plant, milkweed. The insect’s bright coloration serves as a warning that it is not to be eaten.
Keep an eye out for these beautiful butterflies and consider planting a passion vine in your landscape to help them out. The caterpillars may eat the leaves, but in giving them a feast you’ll help them grow into adult butterflies. Once they do mature, they are fantastic at pollinating many of our native wildflowers, further beautifying the world around them.
For more information see the University of Florida’s article here.
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.
Throughout the year, people with citrus trees of any sort may notice some damage to the leaves. Chewing damage, which leaves pieces of the leaf missing, is a common sight. The likely culprit for this type of damage is an insect that is very common in our area, but seems to have multiple personalities!
The adult form of this peculiar creature is the giant swallowtail butterfly, Papilio cresphontes Cramer. A large black-and-yellow butterfly, it is found throughout the country east of the Rocky Mountains, and is present in north Florida most months of the year. Adults spend their days as many other butterflies do, flitting from flower to flower in search of nectar. They are attracted to a wide variety of blossoms, pollinating as they go.
The giant swallowtail butterfly. Photo courtesy of Donald Hall, University of Florida
Females lay tiny round eggs individually on the surface of plant leaves. Though their larvae may eat numerous types of leaves, one of their favorites seems to be those of citrus trees. This means that though the adults may be considered beneficial as pollinators, their caterpillars are often thought of as pests.
Bird poop or caterpillar? The orange dog caterpillar is, in fact, a caterpillar.
Similarly, the beauty of the adult butterfly is quite different than the appearance of their younger selves. The caterpillar of the giant swallowtail, often called the ‘orange dog’ caterpillar, relies on camouflage to keep itself safe. Even with this it displays multiple personalities, so to speak. Larvae of any age may be mistaken as bird droppings on a leaf. Their irregular patches of white and brown make them look like the leavings of a passing avian, which predators are probably likely to pass over. Older caterpillars have another trick up their sleeve, with markings on their head that mimic the head of a snake. Disturb one enough and it may even flash a forked, bright orange protuberance called the osmeterium, which may resemble the tongue of a snake. This gland also emits a musky odor to make the insect even less attractive to potential predators.
Snake or caterpillar? The osmeterium might look like a snake’s tongue, but don’t be fooled. Photo courtesy of Donald Hall, University of Florida
Whether wearing a beautiful, ugly, or scary face, these insects are here to stay. Thankfully, they don’t often do enough damage to citrus trees for homeowners to worry about. Young trees in danger of being defoliated may need some protection, but an established tree can lose a leaf or three with no issues.
If control is called for, hand-picking the caterpillars is a viable option, as long as the tree is small enough to reach the branches. A product called Bt, short for Bacillus thuringiensis, is another option. Applied to the leaves, this insecticide only affects caterpillars, and shouldn’t harm other pollinators.
Syrphid larva and oleander aphids. Photo credit: Lyle Buss, University of Florida.
When we think of pests we tend to focus mainly on insects. Insects make up roughly 80% of animal life, however only about one percent of insects are considered pests. The rest help pollinate crops, kill pests, clean up dead stuff, and make honey. Unfortunately, plants suffer from many more types of pests such as weeds, disease, and us. This episode of “Gardening in the Panhandle LIVE!” was all about managing pests.
Many soft-bodied insect pests can be controlled with insecticidal soap. Many insecticidal soaps are on the market that can help control pests like aphids and whiteflies. However, dish soaps are manufactured for cleaning dishes and not labeled for pest control. More information on insecticidal soaps can be found in the publication “Managing Plant Pests with Soaps”.
Although dish soap isn’t a good option for insect control, there are some things from around the house that can be used to help manage pests. The publication “Do-It-Yourself Insect Pest Traps” offers some excellent options for monitoring and managing pests with traps.
Florida is home to a plethora of insect pests. The Ask IFAS website has many articles on insect pests common in the garden.
Companion planting is the practice of planting two or more plant species close to each other to improve growth and/or pest control of one or more of the species. The article “Companion Planting: What is it?” offers some great recommendations and examples of this technique. Marigolds are an excellent companion plant because they can help deter and suppress nematode populations.
Some people prefer to only use naturally derived products for pest control. The publication “Natural Products for Landscape and Garden Pests in Florida” extensively reviews some of these products. Bacillus thuringiensis (BT) is a bacteria found in soil that can be used for caterpillar pest control.
We love our squash, cucumbers, and watermelons in the South, however there are a number of insects that like to eat them too. More information on cucurbit insect pests and their management can be found in the publication “Insect Management for Cucurbits”.
Armyworms like to feed on just about everything. The Ask IFAS website has a nice collection of publications on all types of armyworms.
Some fungi are fun to eat while others kill our landscape plants. One common fungal disease found in the landscape is Entomosporium leaf spot. This disease is very common on Indian hawthorns. The article “Keep an Eye on Your Indian Hawthorn” describes this disease and it’s control.
Aphids are a very common insect pest. In fact, some plant species have specific aphids. More information on different aphid species and their control can be found in the publication “Aphids on Landscape Plants”.
A plant in the wrong place is considered a weed. Some plants are particularly good at finding the wrong place and can take over our lawns. The publication “Weed Management Guide for Florida Lawns” offers solutions on controlling common lawn weeds.
Cockroaches do a nice job cleaning up litter when they’re outside, but we don’t need want them in our houses whether they’re cleaning up trash or not. The publication “Cockroaches and Their Management” is a great resource for cockroach species identification and management.
As previously mentioned, there are a lot more good insects than bad insects. For more information on predatory insects and biological controls check out the publication “Natural Enemies and Biological Control”.
Nature is fascinating and most people are lifetime learners. To help find out what you’re looking at, give the iNaturalist website and app a try.
Armadillos don’t mean any harm and can be kind of cute. However, they can make a mess of our yard and they build their dens in some undesirable locations. The publication “The Nine-Banded Armadillo” provides information on armadillos and their management.
Fire ants are pests of our lawns and pastures and their sting is brutal. For more information on fire ants please refer to the publication “Managing Imported Fire Ants in Urban Areas”.
Pests can be pesky, but they are manageable if you keep up with the art and science of their control. If you need help with identification and pest management options please don’t hesitate to contact your local Extension Office.
Past episodes of Gardening in the Panhandle LIVE can be found on our YouTube playlist.
