UGA's Great Stinkbug Survey

Cobb Extension has received quite a few calls about indoor stink bugs in the past couple of months, and our county residents are not alone in having an unwelcome influx of the shield-shaped bugs to their homes.

UGA entomologist Paul Guillebeau, who lives in Athens, also noticed that his home was playing host to stink bugs. The species that has caused this year's indoor-insect-consternation is the brown marmorated stink bug; it tends to be present in low numbers, but it only takes one irritated bug to create a big stink inside a home.

Brown marmorated stink bug PHOTO/Brian Little

IPM for Vegetable Gardens, UGA Video

UGA, in cooperation with University of Tennessee and Alabama Cooperative Extension, has put together a short video about pest management in the vegetable garden. As we all gear up for spring planting, keeping the ideas of promoting good health in our crops and of relying as much as possible on beneficial insects for pest control can help us in planning productive, beautiful gardens:

"Warts" on Pecan Leaves Can Be Galls

Wart-like Pecan leaf galls.          PHOTO/Renae Lemon

Over the past couple of weeks, several county residents have emailed photos and/or brought in examples of infested pecan leaves, concerned that their trees may be diseased.

UGA's publication "Pecan Trees for the Home or Backyard Orchard", by UGA specialists Lenny Wells, Will Hudson, and Jason Brock, explains that disease can interfere with good production of nuts, so it is easy to see why our residents would be concerned. A reduced harvest of delicious pecans would be a great loss!

The good news is that, so far, all of the affected leaves have been infested by galls, rather than disease. In the popped-open gall just above the 5 and 3/4 mark on the ruler in the photo above, one of the culprits is just barely visible, looking somewhat like a little white worm.

The University of Kentucky's publication "Pecan Insects"  offers this information about the leaf gall that is typically caused by an insect called Phylloxera:

"This aphid-like pest produces galls on new pecan growth. Leaves, twigs and nuts may be affected. Phylloxera over winter as eggs in bark crevices. In the spring eggs hatch and the tiny nymphs feed on tender young growth, secreting a substance which stimulates plant tissues to develop into galls. When the nymph matures, eggs are deposited in the gall. Young nymphs develop within the gall. The gall splits in several weeks liberating them. Several generations are produced each year, as long as there is fresh young growth on the tree.

Control is initiated with the use of a dormant oil application. During the growing season, controls should target the "crawler" stage before the galls form. Once the gall is formed the damage is done. The crawler is active just before or at bud-break. Controls initiated after the start of gall formation are not effective."

In other words, it's too late to treat now. Many of the infested leaves will fall, and it could be that nut production will be reduced, but the galls do not always appear on the same tree every year. It may help to clean up fallen leaves as part a control program.

A UGA in Thomas County Ag blog post has this to add about Pecan Phylloxera: "Many beneficial insects like lady bugs, lacewings, and syrphid fly larvae feed on phylloxera and eggs after each generation of galls open."

Golden Beetle on Sweet Potato Leaves

It's just about time to harvest the sweet potatoes, and in addition to the gold (sweet potatoes) underground, some gardeners may find flecks of gold on the leaves. Mottled tortoise beetles have been making holes in the leaves of the sweet potato plants for a while now, but they are mostly hidden, on the undersides of the leaves, making them difficult to see.

As the vines are pulled to clear the way for the harvest, the metallic gold of the beetles will become more apparent, glinting in the sun.

The BugGuide website has posted a closeup image of one of these beetles, and North Carolina State University reports, through its IPM section, that leaf damage from these beetles typically isn't severe enough to warrant spraying to control them.

Instead, gardeners can just enjoy the double-dose of gold offered up by the sweet potato bed.

Mottled tortoise beetle on back of a sweet potato leaf, late September.                                PHOTO/Amy Whitney

Baldfaced Hornets: Nest Like a Paper Tornado

Baldfaced hornets are becoming more obvious in yards and parks as their nests and colonies have grown over the summer. Actually a form of yellow jacket wasp, these hornets build nests above ground, usually attached to branches in trees and shrubs.

Baldfaced hornet nest, empty of hornets and no longer attached to the tree.

If one of these colonies is in your yard, you are not alone! UGA's "Stinging and Biting Pests" tells that these colonial insects actually have a broad distribution, having been found in 46 states.

The hornets are fairly large, mostly black, and have, as described in the UGA publication, "white or light yellowish markings on the face, thorax and part of the abdomen."

In the section about controlling these insects, the publication explains, "Most social bees, wasps and hornets are beneficial and should not be controlled unless their nest and activities are close to humans and create a hazard."

Clemson's publication about Baldfaced Hornets points out that these insects act defensively to protect their nests: "Most social wasps vigorously defend their nests from perceived threats. Baldfaced hornets are known for their defensive behavior. People are often stung when they accidentally stumble upon a hidden nest or when the nest is located in areas adjacent to homes or places where there is human activity."

The hornets do have significant redeeming value. Clemson's publication opens with this positive note: "In nature, baldfaced hornets are extremely valuable because they kill many pests including flies, caterpillars, and spiders."

If removing a colony of baldfaced hornets is deemed necessary, it is recommended that a pest-control company be hired, since the task is fairly hazardous. However, all the hornets except new queens will die in winter, at which time a nest that has been left alone may be removed and disposed of safely.

A "Good Year" for Mosquitoes

Last week's deluge was just the frosting on the cake for local mosquito populations, which have become increasingly annoying as the summer has progressed. However, reducing those populations to less pesky proportions is something we can all work toward.

UGA's June 25 Georgia FACES newsletter article by William Tyson, "Recent Rains have Increased Mosquito Populations,"  offers some suggestions for reducing mosquito breeding-grounds around our homes, reminding us all that mosquitoes will reproduce quite successfully in very small puddles that are less than an inch deep. He says,

"Look for and empty clogged gutters, leaf-filled drains, drain outlets from air-conditioners, plastic wading pools, dog dishes, soft drink cans, plastic bags, old tires, birdbaths and potted plant saucers. Even tire ruts, rotting stumps, old tree holes and puddles also need to be addressed. The goal is to eliminate as many sources of standing water as possible."

If water is in a place that can't be drained, or that needs to have water  in it (birdath, for example), he suggests using "Mosquito Dunks" to control the insects in their larval stage (when they are little "wigglers" in the water). The dunks are safe for use around birds and mammals, and they can last for several weeks before needing to be replaced.

Cutting back on their breeding grounds around your own home is usually only a partial solution, because the adult mosquitoes can fly in from other yards and will hang out on tall grass and in the shrubbery. Tyson suggests keeping the lawn mowed and shrubs trimmed to reduce the hiding places for these adult mosquitoes. He also offers a list of pesticides that are effective and safe to use around the home, and a detailed list of places to look for small puddles that might need to be drained. For the complete article, follow the link here.

UGA offers an additional publication on Stinging and Biting Pests that might be in or around the yard. The publication includes photos that can help in identification of the pests and information about eliminating them from your yard.