case

If you have ever seen what looks like clumps of dirt ascending your walls, you are actually seeing an insect. The “dirt” is actually a case that surrounds a household casebearer caterpillar (Figure 1), which is the larval stage of a Tineid moth (Figure 2). The caterpillar creates its case out of silk once it hatches from the egg. You might have actually been correct in believing the case was dirt because, in some cases, the household casebearer will attach soil particles to the outside of its case. Other materials that the caterpillar attaches to the silk include sand, hairs, and insect droppings. The case serves to protect the insect during its immature stages, and it only foregoes its case once it becomes an adult.

The caterpillar never leaves its case, only partially coming out, using its front legs for crawling. The household casebearer caterpillar expands its case as it grows by adding more silk. If you find an immobile case with both ends closed, this is most likely a household casebearer in its pupal stage. The caterpillar seals each side of the case and goes through its metamorphosis within and will emerge as an adult (Figure 2).

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Figure 1. Household casebearer, Phereoeca uterella, caterpillar walking along a surface. Photograph by Lyle Buss, University of Florida.

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Figure 2. Adult, female household casebearer, Phereoeca uterella. Photograph by Lyle Buss, University of Florida.

To learn more about the household casebearer, check out the Featured Creatures page!

For more BugWeek information and activities, visit the website.

If you have questions that weren’t answered by the FAQ, contact us or contact your local Extension office.

This guest post co-authored by Shari Linn, a member of the UF/IFAS Gillett-Kaufman Lab.

 

bed-bug

 

When you have an infestation of bed bugs (Figure 1), bleach should not be used as a control method. Bleach can be harmful to people if not used carefully, and it will not work effectively to completely eradicate bed bugs from your home. Other common household products, such as boric acid dust or alcohol, are also not solutions to a bed bug problem. Control without a pest management specialist can be difficult to handle because bed bugs live on your bed, within wall outlets, around baseboards, and between dresser drawers; however, there are a few approaches you can try yourself.

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Figure 1. An adult bed bug, Cimex lectularius, feeding. Photograph by Lyle J. Buss, University of Florida.

The best approach to a bed bug infestation is Integrated Pest Management (IPM), which combines various control methods. There are many non-chemical treatment options. Vacuuming carpets and furniture physically removes bed bugs. Washing bedding, drapery, and clothing and drying at a high temperature will help reduce the bed bug population. Bed bug-proof cases for your pillows, mattress, and box spring will act as a deterrent.

To learn more about eliminating and preventing bed bugs, click here.

 

For more BugWeek information and activities, visit the website.

If you have questions that weren’t answered by the FAQ, contact us or contact your local Extension office.

This guest post co-authored by Shari Linn, a member of the UF/IFAS Gillett-Kaufman Lab.

 

mosquito-larva

Those little, squirming things in your birdbath are container-breeding mosquitoes (Figure 1). These mosquitoes are in their larval stage. Adult container-breeding mosquitoes lay eggs wherever water collects, which can be natural structures—like bromeliads—or artificial ones with standing water—like your birdbath. The eggs are either laid in batches (called rafts) that float above the water, or singly. When the larvae hatch, they eat fine organic particles from the water.

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Figure 1. Container-breeding mosquito larva, Aedes aegypti. Photograph by Catherine Zettel Nalen, University of Florida.

In Florida, about 13 species of container-breeding mosquitoes exist. A few major species that can be found statewide include the yellow fever mosquito (Aedes aegypti), the Asian tiger mosquito (Aedes albopictus), the Florida St. Louis encephalitis mosquito (Culex nigripalpus), and the southern house mosquito (Culex quinquefasciatus). The aforementioned mosquitoes act as vectors, carrying pathogens that can cause diseases in people such as Zika, yellow fever, dengue, St. Louis encephalitis, and West Nile virus.

To stop container-breeding mosquitoes from thriving in your birdbath, clean it out at least once a week. For more information about controlling and preventing mosquitoes from breeding around your home, click here!

 

 

For more BugWeek information and activities, visit the website.

If you have questions that weren’t answered by the FAQ, contact us or contact your local Extension office.

This guest post co-authored by Shari Linn, a member of the UF/IFAS Gillett-Kaufman Lab.

 

tomato-worm

Between April and November, you might notice spike-tailed green worms (Figure 1) feasting on your tomato plants’ leaves and fruit. These voracious creatures ravaging your garden are caterpillars called tobacco or tomato hornworms. The caterpillars are the larval stage of Sphingidae adults—a family of stout-bodied and narrow-winged moths (Figure 2).

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Figure 1. A tobacco hornworm, Manduca sexta, hanging from the stem of a tomato plant. Photograph by Lyle Buss, University of Florida.

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Figure 2. The tomato hornworm moth, Manduca sexta. Photograph by James Castner.

The hornworm caterpillar in your garden might seem to appear out of nowhere, but it manages to camouflage itself very well while still small. The hornworm causes the most damage before going into the pupal stage, and it is probably then that you became aware of its presence.

Similar to the tomato hornworm is the tobacco hornworm. As its name implies, the tomato hornworm frequents tomato plants, and also feeds on tobacco. Likewise, the tobacco hornworm can be found on tomato plants as well as tobacco. Both species of caterpillar have been found on eggplant, pepper, and potato, though their occurrence on these plants is rare. The tobacco hornworm also develops into a Sphingid moth, but with slight variations in appearance throughout the life stages. In the juvenile stage, the tomato hornworm caterpillar and the tobacco hornworm caterpillar have different colored horns, black and red, respectively. The most distinct characteristic that differentiates the adult moths is a pair of yellow-orange spots that run vertically down the body. The tomato hornworm moth typically has five pairs of spots, while the tobacco hornworm moth usually displays six.

To learn more about these hornworms and how to control them, click here.

 

For more BugWeek information and activities, visit the website.

If you have questions that weren’t answered by the FAQ, contact us or contact your local Extension office.

This guest post co-authored by Shari Linn, a member of the UF/IFAS Gillett-Kaufman Lab.

 

Do wasps have any benefits at all?

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Actually, yes! They may not make honey like pollinating bees do, but we still need them. Even though you might tend to think of wasps as pesky stinging insects, they do provide ecological benefits.

Similar to bees, some species are helpful with pollination. For instance, the fig wasp, Blastophaga psenes, has a mutual relationship with the common fig (Ficus carica). The wasp larvae develop within the figs’ ovaries, and the fig tree depends on the wasps for pollen transfer.

Several wasp species also help to eliminate pests. Adult mason wasps (Zethus spp.) (Figure 1) collect moth larvae for their nests in order for their wasp larvae to be fed. The moth larvae collected are generally considered pests, as some of them can defoliate trees.

Many wasps are parasitoids, meaning the eggs or larvae live on or within their host (“parasitizing” it) and will eventually kill the host. An example of a beneficial parasitoid wasp is Diachasmimorpha longicaudata, which lays its eggs in Caribbean fruit fly (Anastrepha suspensa) larvae—a major fruit fly pest of tropical fruits—and when the wasp larvae hatch, they feed on the fly pupae. Other parasitoid wasps acting as biological control insects include Anagyrus pseudococci (controls mealybugs), Cotesia congregata (controls tobacco hornworms) (Figure 2), and Utetes anastrephae (controls West Indian fruit fly).

 

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Figure 1. Adult mason wasps, Zethus slossonae. Photograph by Sean McCann, University of Florida.

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Figure 2. Parasitoid wasp, Cotesia congregate, pupae on its host, a tobacco hornworm, Manduca sexta. Photograph by Justin Bredlau, Virginia Commonwealth University.

So, as you can see, some wasp species are not problematic to people at all!

This guest post authored by Shari Linn.

ants

It may feel as though ants, no matter what you seem to do, will never leave your house. There are several reasons why ants continue to find their way inside your home. Doing dishes every day and keeping food properly sealed may not be enough to keep ants at bay, because even a single crumb is enough to motivate ants. When one ant comes inside searching for food, it leaves a scent trail using pheromones for other ants to follow. Once another ant comes along the trail, they, too, add their own pheromones to keep the trail active. To inhibit ants from following scent trails, make sure to keep your countertops and floors clean.

Some ants, such as acrobat ants (Crematogaster ashmeadi) (Figure 1), prefer nesting in damp or rotting wood, which may be around windows and drain spouts, though they are rare indoors. Other ant species, such as Florida carpenter ants (Camponotus floridanus), nest in between wall space. In these cases it does not matter how clean your house is. You would need to have your walls inspected for nests and remove decaying wood if infestations persist.

 ants

Figure 1. Adult workers and brood acrobat ants, Crematogaster ashmeadi, in their nest. Photograph by James Castner, University of Florida.

In addition to food and habitat, ants need water to survive, so worker ants will travel great distances in search of water to carry back to the nest. A leaky faucet or dripping pipes are perfect sources of water, so make sure to be on the lookout for these problem areas.

To prevent ants from getting into your home, seal cracks by caulking. You can also use chemical controls as deterrents, which are available in the form of baits. These baits can be found in liquid or granular form. Baits can be taken back to the ant nest and spread poison around, and they can even kill off ant queens.

To learn more about pest ants and control, click here.

This guest post authored by Shari Linn.

 

Fresh spring leaves: A delectable treat

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Throughout early spring, leaf buds on deciduous trees open up into fresh, green leaves. Our recently bare and bland landscapes are green again. We aren’t the only ones who are excited about this, though. Leaf-eating insects are too. Early spring is when many herbivorous insects like caterpillars and beetles eat their hearts (more like their dorsal vessels) out. This is because those new leaves out there are more nutritious and easier to chew and digest than their aged counterparts.

New leaves are more nutritious. Nitrogen is a limiting nutrient for insects, which means the more they can get, the better off they are. Nitrogen content in leaves follows seasonal cycles, peaking in early spring and late fall. Many insects have synchronized their life cycles and feeding behavior to match nutrient cycles in plants. That way, they get the most out of what they eat.

New leaves are easier to chew and digest. Younger leaves are not as thick, have less cellulose and lignin (building blocks of plant tissue), and are generally not as tough as mature leaves. For chewing insects like caterpillars and beetles, tough leaves mean less eating, slower development, and more wear and tear on those mouthparts. Like cutting hair with dull scissors. Not only are new leaves less physically challenging, but they also contain fewer defensive compounds like tannins and resins. When insects eat tannins, they aren’t able to break them down and digest the leaf material. Oaks are a great example of a tree that produces high concentrations of tannins in their leaves.

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Herbivory on oak leaves. Photo: A.G. Dale

Many insects have evolved adaptations to overcome these common plant defenses, but these spring insects choose one of the simplest ways to succeed: avoidance. Take a walk around your home this spring and see if there are signs of herbivore feeding on the newly expanded leaves. Many times you’ll find half-eaten leaves but you can’t find an insect anywhere. This is when your investigator skills come in handy.

You can figure out what is eating your leaves by looking for evidence of the pest. For example, caterpillars often leave a trail of frass (their poo) behind on leaf surfaces. In the photo below, you can see a few fras droppings beneath this tussock moth caterpillar that was feeding on my oak tree.

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Tussock moth caterpillar feeding on oak leaves with frass droppings below. Photo: A.G. Dale

If there are no droppings to be seen, perhaps the culprit is a leaf-feeding beetle. Last night I was walking through my back yard and found several leaf beetles eating leaves on an oak tree (image below). When I went out there this morning they were nowhere to be found. If you have mysterious herbivory, go out at night with a flashlight and take a look.

Leaf beetles feeding on oak leaves at night. Photo: A.G. Dale

Most often, these caterpillars and beetles are present in low enough numbers that they don’t warrant any kind of control measure. Trees are extremely resilient and usually produce another set of leaves if their first set are eaten. However, if these insects completely defoliate trees year after year, it will take its toll.

Go outside and see what diversity of insects are getting to work on your landscape plants. Who knows, you may see something you have never seen before. I did today. Then, take a walk around your yard in a few months and see if the dark green, older oak leaves are getting eaten as much. I bet not.

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Welcome to the new online habitat, er, home for the University of Florida’s Bug Week!

The UF/IFAS Web Team has designed this terrific new website, where you’ll find information about all the Bug Week 2016 activities, along with plenty of educational material.

To kick things off right, we’d like to invite all our users to visit the “What’s Bugging You” page, which answers Frequently Asked Questions about Florida bugs, and is an example of an “FAQ” feature. We’ve been adding material to it for several years now.

You can find the FAQ here and you can use the search function on the page to search the FAQ by keyword.

We’ll be adding new material in the weeks to come, so check the Bug Week website, or follow us on Facebook and Twitter to see the new FAQ items when they’re posted.

 

What are these tents?

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You may have noticed branches covered in these strange structures (Figure 1) during the spring, typically in March. These are tents constructed by eastern tent caterpillars, the larval stage of a Lasiocampid moth—a hairy and golden-brown colored moth with two white bands on the forewings. They spin their silk around tree trunks or branches to create a protective barrier against predators. The caterpillars congregate inside their tents to rest after feeding or to molt (Figure 2). They will emerge to feed on nearby leaves of their host tree. Usually the larvae will build their cocoon inside the tent.

The fall webworm larvae, caterpillars of some Erebid moth species (adults have hairy bodies and are all white or white with brown patches) also construct similar silk tents around host plants. These caterpillars typically form tents around the ends of tree branches, such as on oak, mulberry, and hickory, beginning in May to August.

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Figure 1. Silk tent made by the eastern tent caterpillar, Malacosoma americanum. Photograph by Lyle Buss, University of Florida.

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Figure 2. Eastern tent caterpillars, Malacosoma americanum, surrounding their silken tent. Photograph by James Castner, University of Florida.

Due to the eastern tent caterpillars’ feeding habits, they can be detrimental to the health of the tree. Since the caterpillars feed on leaves, during outbreaks they can defoliate their host tree: cherry, hawthorn, wild plum, and various other tree species. Luckily, the tree tends to survive, and might just experience less growth (with branch and leaf loss) than if it had not been the host of the caterpillars.

These caterpillars are not the only creatures capable of building webbed structures on trees in Florida. Webbing barklice can also make silken webs over branches and tree trunks in live oak hammocks and cabbage palm stands.

To learn more about eastern tent caterpillars, click here!

 

This guest post authored by Shari Linn, Fall 2015 Entomology Intern.

Are ladybugs all ladies?

lady bug

The ladybug (Figure 1), or ladybird, is the common name given to beetles in the Coccinellidae family. This is misleading because not all ladybugs are ladies; they can be either female or male. It is difficult to determine the sex of a ladybug, but females tend to be larger than males. People, mostly children, are confused by the name. Why else would the beetles all be called ladies? It is not unreasonable to think only females exist. There are various insects that are parthenogenetic, which means they do not require a male to mate. These insects only produce female offspring, but that is a topic for a different article altogether! The ladybugs’ favorite food sources can actually reproduce via parthenogenesis, such as some species of aphids and mealybugs.

lady bug

Figure 1. Spotted, orange multicolored Asian lady beetle, Harmonia axyridis Pallas, on a leaf. Photograph by Russell F. Mizell, University of Florida.

As it turns out, the name was shortened from “beetle of our Lady,” which Europeans coined in the Middle Ages. Pest insects had been devouring crops, so farmers prayed to the Virgin Mary for help, and when ladybugs miraculously came to eat the pests, they believed it was a gift from their Lady.

Today, we still value the economic importance of these beetles. The red and black (and sometimes orange) coloration may be a deterrent to predators, like birds, but people recognize the familiar, usually-spotted insect as a garden and crop helper. To learn more about these beneficial organisms, watch this video here.

This guest post authored by Shari Linn, Fall 2015 Entomology Intern.