This caterpillar can sting – what is it?

November 30, 2015September 2, 2014 by Willie Chance

This information came from the UGA publication, Stinging and Biting Pests by Elmer Gray, UGA Entomologist. See the original publication for more information on stinging and biting insects

The caterpillars of some moths have sharp, hollow spines or hairs that contain venom. Contact with these spines causes a burning inflammation of the skin, but can be more serious when in contact with a mucous membrane or the eyes. The spines from dead caterpillars are still problematic. Most of these caterpillars feed on the leaves of various hardwood trees and shrubs and contact with people is uncommon. The venomous spines are a defense mechanism and the colorful patterns or unusual body shapes serve as a warning to their enemies. About 25 species have spines that can be painful. Three of the more common species are described below.

Puss Caterpillars:

Puss caterpillars may be pale yellow, gray or reddish brown, about 1 inch long and densely covered with hairs. Among these hairs are hollow spines with venom. Stings on the hand can cause the entire arm to swell and become numb. Later, there can be severe pain followed by itching. Young children are often more severely affected. Large population increases in local areas can cause a problem.

Saddleback Caterpillars:

The saddleback caterpillar is approximately 1 inch long and has a brown slug-like body with a green mid-section. In the middle of the green midsection there is a distinctive brown saddle mark with a white border. Venom-filled spines are located on fleshy “knobs” on all sides of its body. Contact with this caterpillar’s spines can be extremely painful and severe reactions are possible for sensitive individuals.

Hag Moth Caterpillars:

The hag moth caterpillar is a strange-looking brownish caterpillar with six pairs of curly projections, three long and three short, coming from the flattened body. The plume-like projections on its back project out to the sides, suggesting the disarranged hairs of a hag. Among the brown hairs on the projections are longer black stinging hairs. These caterpillars are solitary and can easily be mistaken for leaf debris.

Control:

Control is usually not needed since contact is uncommon and these caterpillars are usually solitary. If a number of stinging caterpillars are seen feeding on the foliage around areas where children are active, spray the foliage with an insecticide labeled for tree and shrub application. Remember, dead caterpillars can still cause painful stings. Spread a cloth or plastic sheet under a tree or shrub to collect the fallen dead caterpillars, and then carefully dispose of them.

Find other Stinging and Venomous Caterpillars here.

Why do these lantana have injured leaves and no blooms?

November 30, 2015August 15, 2014 by Willie Chance

Lantana Lace Bugs Can Stop Bloom!

Why do these lantana have injured leaves and no blooms? — Lantana lacebug injury, Chazz Hesselein, Alabama Cooperative Extension, Bugwood.org

Lantanas can bloom from June through early October in Georgia. Lantana lace bug can stop blooming in the summer leaving green plants with no blooms. The lantana lace bug is a small brown insect up to 1/6 inch long. Adult lace bugs are long, oval insects with a midsection that is slightly wider than the ends. The rear of the lantana lace bug is blunt but rounded off. The young are dull-colored and spiny. Look for the lantana lace bug by shaking the branch over a piece of white paper or light-colored cloth.

Lace bugs feed on the bottom of the leaves and on young flower buds. They make the top of the leaves speckled with white, similar to mite injury. Underneath the leaf you may see brown, tarry spots that are the insect’s droppings. Since lace bugs feed on young flower buds, lantana bloom may be severely reduced or stopped completely. When populations are very high, the lantana leaves may turn almost white and fall from the plant.

Cultural Control:

Lace bugs do have several natural enemies that help to control their numbers – spiders, lacewing larvae, assassin bugs and predaceous mites. Be careful using pesticides to preserve these natural enemies of the lantana lace bug.

Planting less susceptible varieties of lantana may help reduce lace bug numbers though this may not completely control lace bugs:

Lantana that are less susceptible to lantana lace bug:

Weeping White, White Lightning, Weeping Lavender, Imperial Purple, Patriot Rainbow, Denholm Dwarf White, Radiation, Dallas Red, Gold Mound, New Gold and Lemon Swirl

Cultivars of Lantana montevidensis

Small leafed varieties seem to be less susceptible than large leafed varieties, although both types can be attacked by lantana lace bugs.

Lantana that are more susceptible to lantana lace bug:

Patriot Desert Sunset, Pink Frolic and Patriot Sunburst

If cultural and natural controls do not limit the lace bug population, you may need to treat with chemicals.

Chemical Control:

See the UGA Pest Management Handbook for pesticide recommendations. Read and follow all label directions when using pesticides. This is especially important now since some pesticide labels have changed.

Check the plants in two weeks after the first treatment and treat again if needed. Once you control the lace bugs, the blooms should slowly return if temperatures are warm enough and other growing conditions are good.

For more information:

Caterpillars feeding on shrubs and trees in the fall

November 30, 2015August 14, 2014 by Willie Chance

In the fall, there are several caterpillars that feed on the leaves of trees and shrubs. Although the leaf damage may look significant, the plants may not be as damaged as one may think. You need to understand the type, size and the growth phase of the plant and the type of caterpillar you have before deciding whether to control them.

Deciduous trees will soon be losing their leaves anyway. Foliage feeding by caterpillars is likely to cause little injury. The leaves are going to fall off anyway.

For evergreen trees, foliage loss will be more likely to affect the tree and control is more likely to be needed. For evergreen trees, especially avoid defoliation of entire limbs since these often do not recover.

Bagworms are a long lasting problem since the bags contain hundreds of eggs which will hatch next year. Unfortunately, at this time of year you will need to pick off the bags and destroy them since the bags are sealed now and pesticide cannot easily get inside. Remove the bags you can see right now and plan to check these plants for small bagworms next May.

Young trees or trees weakened by other factors may be more likely to be damaged by loss of foliage to caterpillars than younger, healthy trees.

Evergreen shrubs retain their leaves throughout the fall and winter and into next year. Injured leaves on evergreen shrubs will be visible until they fall naturally – which could be a year or more from now. Control decisions on shrubs should be based on the level of aesthetic injury the home owner will accept.

Deciduous shrubs, like deciduous trees, will be losing their leaves soon and foliage loss to caterpillars in the fall is less likely to cause a lasting problem.

For information on control measures, see these resources:

IPM for Select Deciduous Trees

Pest Management Handbook

Contact your local Extension Office

Forest Pest Insects in North America: a Photographic Guide

Fall Armyworms in Turf

November 30, 2015August 6, 2014 by Willie Chance

Will Hudson¹, Cheri Abraham² and Kris Braman¹

¹ UGA Entomologists and ²Field Operations Manager/ Entomologist at US Citrus, LLC

Fall Armyworms in Turf — Large armyworm. Photo by Kris Braman, UGA Entomologist

In late summer, almost every year, caterpillars invade turfgrass throughout Georgia. The damage to established turf is mostly aesthetic, but newly sodded or sprigged areas can be more severely damaged or even killed. While there are several caterpillars that can damage turfgrass, in late summer most of the problems are from fall armyworms.

Hot, dry weather can intensify fall armyworm problems when egg-laying adults concentrate their eggs in irrigated, green turf. At least some cultivars of all warm season grasses are susceptible. Cool season grasses like tall fescue are very favorable for fall armyworm growth and development too, and do not regenerate as readily as the stoloniferous grasses.

Fall armyworm adults migrate northward every year from southern overwintering areas. Adult armyworm moths are active at night and females lay eggs in masses of 50 to several hundred. These night-flying moths are attracted to lights and to lighter colored surfaces. Egg masses on structures around turf (eaves and gutters, fence and porch posts, flags on golf courses) and even on taller foliage plants can be the first indicators of incipient infestations.

Eggs hatch in a few days, and the young larvae begin to feed on leaf tissue. Damage from small larvae may at first look like skeletonizing, but as the worms grow, the entire leaf is consumed. Small larvae at this time are easier to control and have inflicted less damage than full grown (35-50 mm long) larvae. Full grown larvae will soon pupate in upper soil/thatch layer and will not be susceptible to insecticides at this point.

Armyworm larvae are most active early and late in the day, spending the hotter hours down near the soil in the shade. Larvae feed for 2 to 3 weeks before pupating in the soil. Moths emerge 10 – 14 days later. The entire life cycle from egg to adult moth takes about 28 days in the warm weather of August and September.

If there is any doubt about whether worms are present, pouring soapy water on the grass (1/2 oz. dishwashing soap/gallon water) will bring them up very quickly. Heavily infested turf will also have visible greenish-black fecal pellets on the soil surface. Other indicators of armyworm infestations may include birds or even paper wasps that use the fall armyworms as food.

Control of Armyworms

Control of armyworms and other turf caterpillars is relatively simple once the problem is identified. There are several pesticides from which to choose depending upon the site you are treating. Consult the UGA Pest Management Handbook or your local Extension Agent for recommendations. Read and follow all label directions when using pesticides.

Armyworms are most active late in the day and at night, so pesticide applications should be made as late as practical for best results. It is not necessary to water after application but an application rate of 20 – 25 gallons of solution per acre as a minimum will ensure good coverage. Cutting the grass prior to application may improve control, but do not cut grass for 1 –3 days after application.

In addition to the birds and paper wasps mentioned above, a number of other insects feed on armyworms, including tiger beetles and other ground beetles. Fall armyworms, like many other turf infesting caterpillars can also be heavily parasitized by tiny wasps that kill the caterpillars and cause no harm to humans or pets. These natural enemies can be conserved by spot rather than blanket spraying and properly timing control efforts.

What is this large spider hanging around in landscapes?

November 30, 2015August 4, 2014 by Willie Chance

Female Golden Garden Spider, Image by Hancy Hinkle

The picture is of a Yellow Garden Spider which are often seen in the landscape in late summer and fall. Read on to learn more about this and another fall spider.

Late Summer & Autumn Spiders

Nancy C. Hinkle, UGA Department of Entomology

Between now and Halloween we will be seeing more spiders around our yards. The first hard frost will kill them off. Now they are mating and producing egg sacs so their eggs can overwinter and re-establish the population next spring. There are two orb-weaver spiders with large webs that are most commonly seen.

Barn spiders (Araneus cavaticus) can be found on porches, where flying insects attracted to porch lights get trapped in their webs. These spiders are nocturnal, constructing a new web every evening and taking it down before dawn. This rusty brown spider has legs extending about 2 inches, making it look large and noticeable. These spiders hide during the day, but at night are found in the middle of the web, waiting for insects to be trapped.

The yellow garden spider (Argiope aurantia) is one of the longest spiders we have here in Georgia. It is frequently found in gardens and around shrubbery where it constructs large webs to entrap flying insects. The abdomen has distinctive yellow and black markings while the front part of the body, the cephalothorax, is covered in white.

The female yellow garden spider typically remains in one spot throughout her life, repairing and reconstructing her web as it is damaged and ages. Her web may have a distinctive zigzag of silk through the middle, explaining its other common name, “writing spider.” Unlike the nocturnal barn spider, the yellow garden spider can be found in its web anytime. Sometimes a smaller spider will be found in the web with her; this is the male garden spider.

These spiders have been present all summer, eating pest insects and growing. By late summer they are large enough that people start noticing them. Remember,Georgia has over 800 species of spiders, all of which are harmless if you leave them alone. All spiders are more afraid of you than you are of them.

For more information:

Call your local Extension Agent at (800) ASK-UGA1 or locate your local Extension Office.

Stinging and Biting Pests of People

Golden Garden Spiders

Pest Management Handbook Follow all label recommendations when using any pesticide

The Dreaded Squash Vine Borer

November 30, 2015July 30, 2014 by Becky Griffin

If you have grown squash for very long you have probably run across the dreaded squash vine borer (Melitta curcurbitae). One day your plants look great and the next day the plants look wilted. Shortly after they collapse and die. The base of the plant becomes mushy. You may even see small holes at the stem base. Squash vine borers have probably paid your garden a visit.

Squash Vine Borer Photo by Jim Jasinski, Ohio State University Extension, Bugwood.org

To understand how to control this pest we need to understand a bit about its biology. In June/July adults emerge from under the soil. They fly during the daytime and lay a single egg at the base of susceptible plants like squash and pumpkins. After about a week the egg hatches and the larva bores into the plant stem. The insect will feed through the center of the stem for several weeks. Then the larva will exit the stem and burrow back into the soil to pupate until next summer where it emerge as an adult. There is one generation per year.

Knowing this biology we can use integrated pest management (IPM) to help combat this pest. Choose plants that the vine borers don’t like. Gardeners have had success with moschata types of squash like butternut. Their stems seem to be more resistant to the borer. Next, especially if you have ever had vine borers, you must rotate your crops. Don’t plant squash in the same place next year because the pest is in the soil waiting until next summer to emerge.

If you have planted in an area that does not have a history of squash vine borers you can use row covers (simply structurally supported netting) to block the flying adults from laying eggs. As soon as the squash starts to flower you will need to remove the row covers to give the necessary pollinators access to the flowers. Some gardeners have had success with trapping. The adults are attracted to the color yellow. Some gardeners use yellow bowls with filled with water. The thought is the yellow bowls will attract the insects and they will drown. Yellow sticky traps are also available.

Squash Vine Borer Larva Photo by Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org . — Squash Vine Borer Larva Photo by Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org

Change your squash planting time. If you can plant very early so that the squash will be mature and fruited before the adults lay eggs, you might outwit the pest. When the squash plant has finished producing vegetables, remove it from the garden.

What if it is too late and you are already infected with squash borers? One recommendation is to make a sharp slit in the stem and remove the borer. Afterwards pile soil around the stem so that the wound is covered with soil. Insecticides can be used for prevention but once the pest is inside the plant, insecticides aren’t very helpful.

If your crop is a complete failure, your local Farmers Market will probably have some squash and you can try again next year.

Contact your UGA Extension Agent for more information on combating the vine borers. Also, visit Homegrown Summer and Winter Squash by Florkowska and Westerfield for other tips on growing squash.

Happy Gardening!

City Heat Boosts Tree-Killing Scale Insect Populations

November 30, 2015July 20, 2014 by Willie Chance

A red maple branch heavily infested with gloomy scales (identified by the small bumps covering the bark).

From Entomology Today

Big cities with large expanses of concrete, asphalt, and buildings are usually warmer than the suburbs or countrysides that surround them, a phenomenon known as the urban heat island effect. Now new research from North Carolina State University shows that these urban heat islands increase the number of young produced by the gloomy scale insect — a significant tree pest — by 300 percent, which in turn leads to 200 times more adult gloomy scales on urban trees.

Read the original article here

Japanese beetles return to Georgia landscapes

November 30, 2015July 14, 2014 by Willie Chance

Paul Pugliese, Agriculture & natural resources agent for the University of Georgia Cooperative Extension office in Bartow County

Japanese beetles dine on canna lily branches Image credit - Sharon Dowdy. — Japanese beetles dine on canna lily branches Image credit – Sharon Dowdy.

With their metallic copper and blue-green bodies and bronze wings, Japanese beetles might be considered beautiful if not for the damage they cause. The plentiful beetles munch holes into the leaves of landscape plants leaving what is often described as skeletal remains.

Prior to last year, Georgia had a few years of drought and unusually mild winters. The warm, dry soil conditions were not conducive for Japanese beetle grubs to survive over the fall and winter throughout most of Georgia. This gave Georgia gardeners and landscapes a nice reprieve from the pest and its damage.

Perfect conditions return

This past winter was ideal for Japanese beetle grubs and home and commercial gardeners are suffering through a resurgence of adult beetles this summer. The severity of local Japanese beetle populations varies depending on temperature and soil moisture. Most surveys indicate that Japanese beetles do not occur further south than the “fall line” between Macon and Augusta in Georgia. Yet, they can be found as far north as Canada.

If you’ve fought Japanese Beetles before, there’s a good chance they will return to your landscape – especially if your have some of their preferred plants. Japanese beetles feed on more than 300 species of broad-leaved plants but prefer about 50 species. Commonly attacked hosts include peach, cultivated and wild grapes, raspberry, plum, roses, apple, cherry, corn, hibiscus, hollyhock, dahlia, zinnia, elm, horse chestnut, linden, willow, crape myrtle, elder, evening primrose and sassafras.

They love leaves

The good news is the beetles only affect the leaves of trees and shrubs, so healthy plants can tolerate significant leaf loss without long-term consequences.

Adult Japanese beetles live four to six weeks, lay eggs (mostly in mid-August) and die. If the soil is sufficiently moist, the eggs will swell and produce larvae in about two weeks. The rest of the year, the beetles live underground in a larval stage feeding on the roots of grass and other plants before maturing into adult beetles in the summer.

Japanese beetle larvae are plump, C-shaped white grubs often seen in the spring when garden soil is first tilled. The grubs need soil moisture to survive the winter. Frequently irrigated lawns and landscapes tend to have higher grub populations.

Adult beetles emerge from the soil and begin seeking out plants for food in late May and early June. The first round of beetles are known as “scouts” because they find a good food source and release pheromone scents to attract more beetles. The masses then gather to feed and mate.

Control the first ones!

The key is to catch the early arrivers as soon as possible. Handpick or knock adult beetles off plants and drown them in soapy water. This is an effective control option for managing small infestations and preventing them from attracting more beetles.

Pheromone lure traps are not recommended for general Japanese beetle control in a small garden. They tend to attract more beetles to the area than would normally be present. Trapping should be done in areas away from gardens or landscapes to lure beetles away from desired plants.

Adult beetles can be controlled with over-the-counter insecticides. During heavy beetle outbreaks, sprays may be needed every seven to ten days to protect high-value, specimen plants like roses. A single application of a longer-lasting systemic insecticide, like imidacloprid, needs to be made 20 days before adult Japanese beetles are expected — usually around mid-May. Most systemic treatment options are not labeled for use on plants that produce edible fruits. Read and follow pesticide label’s application rates and safety precautions.

Controlling the grub stage generally has little effect on the overall damage caused by adult beetles, since adults can fly into your landscape from up to a mile away. Most homeowners rarely have grub populations large enough to cause damage to home lawns. Treatment may be necessary if more than five to ten grubs per square foot are present in lawns. Late summer and early fall insecticide applications are most effective at killing young grubs.

Do you recognize this large wasp found in landscapes now?

November 30, 2015July 13, 2014 by Willie Chance

Cicada Killer Wasps

Nancy Hinkle, UGA Extension Entomologist

Cicada killer - Jessica Lawrence, NC State Entomology Department, Bugwood.org — Cicada killer – Jessica Lawrence, NC State Entomology Department, Bugwood.org

The cicada killer wasp is the largest wasp in Georgia. The cicada killer wasp is almost two inches long. Although intimidating in appearance, these wasps are not something we humans have to worry about. Cicadas, on the other hand, should be very afraid. Cicada killer wasp adults feed on nectar but use paralyzed cicadas to feed their young.

Female cicada killers are hard to provoke to sting. The female uses her stinger to paralyze her prey (cicadas) rather than in self defense. The female’s attention is focused on providing food for her babies, so she poses little threat to humans.

Cicada killers prefer to nest in sandy open sunlit areas. As the female digs, she kicks out soil that forms a semicircle around the burrow opening. She burrows six to ten inches into the ground, prepares a chamber, catches a cicada to fill the chamber, lays an egg on the cicada, and seals the chamber. She may do this over a dozen times in one burrow.

Cicada-killer-Ronald-F.-Billings-Texas-Forest-Service-Bugwood.org_-300x200 — Cicada killer – Ronald F. Billings, Texas Forest Service, Bugwood.org

When a female finds a cicada, she paralyzes it with her stinger, straddles it, and attempts to fly with it to her burrow. Because the cicada typically weighs more than she does, these flights are usually hops, with more dragging than gliding.

The egg hatches in a few days and the larva feeds on the paralyzed cicada until nothing is left but a shell. Then the wasp larva pupates within the burrow, remaining there until the next spring.

Males cannot sting; their only defense is intimidation. They patrol the nesting area, trying to divert attention away from the female, allowing her to provision her nest with cicadas. Meanwhile the male is using threatening tactics to distract potential predators. He may even dive bomb perceived threats. Since the males do not have stingers, they are completely harmless. They must rely on bluff, bluster, and bravado to protect their families.

Because cicada egg laying can be damaging to trees and shrubs, cicada killer wasps are very beneficial, providing free biological control. However, homeowners who do not want these wasps around can modify their lawn to be unappealing. A thick healthy turf with no bare spots will exclude cicada killer wasps. If turf is thin in nesting areas, identify turf problems that make the turf weak and correct them.

Cicada killer wasps will be active for only a few weeks and will be gone by mid-August in most of Georgia. If someone is bothered by these wasps, late July and early August would be a good time to take their vacation.

For more on cicada killer wasps, see these articles:

Giant wasps not after humans

Killer wasps swarm in August

Prevent White Grubs Now

November 30, 2015July 11, 2014 by Willie Chance

Will Hudson, UGA Extension Entomologist

June and July are excellent times to prevent white grubs in turf. White grubs live in the soil and feed on the roots of turf. Most white grubs have a one year life cycle in Georgia. Adult beetles lay eggs in late spring or early summer. The eggs hatch into grubs which feed and grow through the summer and fall, then dig down to spend the winter deep in the soil. They become active as the soil warms in the spring, and feed for a few days to a few weeks, depending on the species. They then turn into pupae before emerging as adult beetles to continue the cycle.

White grubs are the immature stage of Scarab beetles like green June beetles, Japanese beetles, chafers and others. The scarabs are a large family of beetles, and there are perhaps two dozen different species of white grub that might be found feeding on the roots of turf in Georgia. Included in this group are some of the most serious insect pests a turf manager will face.

White grubs damage turf by feeding on the roots during the summer and fall and, to a lesser extent, in the spring before pupation. Very dry conditions can reduce survival of both eggs and small grubs.

Symptoms of white grub damage are similar to other factors that damage the root system – disease, soil compaction, poor fertility, or drought. Except for the green June beetle, grubs never come to the surface until they become adults. The only way to tell if a lawn is infested is to dig the grubs up.

To scout for white grubs, cut 3 sides of a square of turf and lay the grass back like a carpet. Dig gently in the soil to a depth of 4 inches and count the grubs you see. It is important to identify the grubs before you treat. The potential for turf damage is dependent on the number and types of white grubs present. Your county agent can help identify grubs or see the publication White Grub Pests of Turfgrass on the CAES Entomology Department website.

It is easiest to find white grubs in early spring and late summer (late August) when they are larger and easy to see. That is not the best time to treat, however. Treatments are more effective if applied while grubs are small. In most of Georgia, this means application in June or July for best control. Once white grubs get bigger, there are fewer effective options and higher pesticide rates will be required. Good soil moisture and watering in the pesticide is also important for white grub control.

See White Grubs of Turfgrass for good information on control measures. Consult the Georgia Pest Management Handbook for current pesticide recommendations. Follow all label recommendations when using any pesticide.

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