Quizes – Page 2 – Center for Urban Agriculture

What is killing branches on this Leyland Cypress?

November 30, 2015July 24, 2014 by Willie Chance

Bot canker - Dark, rust-colored dieback symptoms of Botryosphaeria (Bot) canker. G. Moody — Dark, rust-colored dieback symptoms of Botryosphaeria (Bot) canker. G. Moody

This disease is Bot canker. Bright, rust-colored branches and yellowing or browning of shoots or branches are the first observed symptoms. Closer inspection reveals the presence of sunken, girdling cankers at the base of the dead shoot or branch. Sometimes, the main trunk shows cankers that might extend for a foot or more in length. These cankers rarely girdle the trunk, but they will kill branches that may be encompassed by the canker as it grows. Read more info in the following publication including disease management.

Diseases of Leyland Cypress in the Landscape

See Entire Publication

Authors – Alfredo Martinez, UGA Plant Pathologist, Jean Williams-Woodward, UGA Plant Pathologist and Mila Pearce, Former UGA IPM Homeowner Specialist

Leyland cypress has become one of the most widely used plants in commercial and residential landscapes across Georgia as a formal hedge, screen, buffer strip, or wind barrier. The tree is best suited for fertile, well-drained soils. However, when young, the tree will grow up to 3-4 feet per year, even in poor soils. The tree will ultimately attain a majestic height of up to 40 feet.

Leyland cypress is considered relatively pest-free. However, because of its relatively shallow root system, and because they are often planted too close together and in poorly drained soils, Leyland cypress is prone to root rot and several damaging canker diseases, especially during periods of prolonged drought. Disease management is, therefore, a consideration for Leyland cypress.

This UGA Publication discusses several Leyland Cypress diseases and their management.

What is the relationship between WNV infection and mosquito control programs?

November 30, 2015July 21, 2014 by Willie Chance

Answer: This study indicated that people in areas with no mosquito control program had a tenfold greater risk of WNV than those in areas where mosquitoes were controlled.

Read the entire article Using Mosquito Surveillance Data taken from the April 10, 2014 issue of Dideebycha, newsletter of the Georgia Mosquito Control Association

Mosquito surveillance is an important component of any mosquito control program. Where arboviral diseases occur, mosquito testing is an equally important component of an arboviral surveillance program. Arboviral encephalitis can be prevented in two major ways: personal protective measures to reduce contact with mosquitoes and public health measures to reduce the population of infected mosquitoes in the environment (mosquito control). Analysis of surveillance data provides information about the timing of arboviral transmission and the risk to the public, which can trigger county-level educational programs to help reduce risk.

A study comparing two mosquito control districts showed that the program with the most mosquito surveillance and best documented larviciding and adulticiding operations had the fewest number of WNV cases. This study indicated that people in areas with no mosquito control program had a tenfold greater risk of WNV than those in areas where mosquitoes were controlled.

Southern House Mosquito, Pest and Diseases Image Library, Bugwood.org

What are the roadblocks to arboviral surveillance in Georgia? We really do not have enough data to do good predictive calculating, particularly at the State level. Predicting where and when WNV outbreaks will occur is difficult, especially in areas with endemic transmission, which is what occurs in Georgia. Most of our sentinel data do not match up with our case data, as counties doing mosquito surveillance are not necessarily the same counties where human cases are occurring. Culex quinquefasciatus (Southern house mosquito), our primary WNV vector, are not evenly distributed, so neither is risk of human cases. However, we do not have sufficient surveillance to know where risk is occurring, and maintaining mosquito monitoring systems is costly even though it is essential according to the CDC.

Where data are available, the best predictor of risk is the Vector Index, the minimum infection rate (MIR) times the number of mosquitoes per trap night (abundance), which provides 2-4 weeks lead time in advance of human cases. Where adequate surveillance is maintained, this gives sufficient lead time to implement adult mosquito control efforts, which have demonstrated success in reducing human risk, resulting in fewer WNV cases (Carney, 2008).

Reference: Carney, R.M., Husted, S., Jean, C., Glaser, C., & Kramer, V. (2008). Efficacy of aerial spraying of mosquito adulticide in reducing incidence of West Nile Virus, California, 2005. Emerging Infectious Diseases, 14(5), 747–754.

Can we use the behavior of these ants to better control them?

November 30, 2015July 17, 2014 by Willie Chance

Ants engage in a social behavior known as trophallaxis, or food sharing, during which food (including bait) is distributed among nestmates.

Information on using bait formulations for insect control. Taken from the publication Insecticide Basics for the Pest Management Professional

Daniel R. Suiter, UGA Department of Entomology & Michael E. Scharf, UFL Department of Entomology and Nematology

See the rest of the publication at Insecticide Basics for the Pest Management Professional

Bait Formulations. Baits must be eaten by the target pest — typically rodents, termites, ants, cockroaches, and other miscellaneous pests (Figure 2). Baits are comprised of an active
ingredient incorporated into a palatable, if not preferred, food source. Bait products usually contain inert ingredients (e.g., preservatives, thickeners, gels, and fillers) intended to stabilize and enhance the shelf life and palatability of the bait. Logically, it is important that bait ingredients (actives and inerts) not be a deterrent to feeding.

Baits are most commonly formulated as ready-to-use liquids, gels, pastes, granules, dusts,
stations, pellets, and blocks. Depending on the product’s label, baits can be used both indoors
and outdoors, are generally target-specific, and are considered environmentally-friendly
because only small amounts of active ingredient are delivered, usually from a point source.
Because baits must be eaten, it is important to keep them away from non-target organisms.

To facilitate bait consumption:

Neither the active ingredient nor any other part of the bait should be a feeding deterrent.
The food source should be palatable (perhaps even preferred) by the target pest.

In addition, for social insect pests (especially ants) it is important that the active ingredient be slow acting. Ants and termites share food with their colony mates in a social behavior known as trophallaxis (Figure 1). Trophallaxis results in active ingredient distribution throughout social insect colonies. It is, therefore, important that the active ingredient be slow acting over a range of concentrations in order to provide sufficient time for toxicant distribution among nestmates. Fast-acting active ingredients or excessively high concentrations of the active ingredient may too quickly impair a social insect’s ability to engage in trophallaxis, thereby rendering the bait less effective.

See the rest of this publication at Insecticide Basics for the Pest Management Professional

How do we control this wood chewing pest?

November 30, 2015July 2, 2014 by Willie Chance

Info taken from the publication Biology and Management of Carpenter Ants by Dr Dan Suiter

Carpenter ants are so-called because of their habit of chewing wood to create nest sites. They do not eat wood, like termites, but they excavate it with their strong, saw-like jaws to create random galleries where they nest. Carpenter ants are also a nuisance because of their abundance and large size. Finding Nests Is Key to Eliminating Carpenter Ants

See more information in the publication including:

An unusual lawn invader appears during wet weather

November 30, 2015June 19, 2014 by Willie Chance

This is a Slime Mold growing on turf.

This information is taken from the UGA publication, Turfgrass Diseases in Georgia: Identification and Control

Slime molds are caused by the fungi Physarum spp. and Fuligo spp.

All turfgrasses are susceptible to slime molds

Symptoms: Large numbers of pinhead-sized fruiting bodies may suddenly appear on grass blades and stems in circular to irregular patches 1-30 inches in diameter. Affected patches of grass do not normally die or turn yellow and signs of the fungi usually disappear within 1 to 2 weeks. These fungi normally reproduce in the same location each year. The fungi are not parasitic, but they may shade the individual grass leaves to the extent that leaves may be weakened by inefficient photosynthesis.

Conditions favoring Slime Molds: Slime molds are favored by cool temperatures and continuous high humidity. An abundance of thatch favors slime molds by providing food directly in the form of organic matter.

Management:

Remove slime mold by mowing.

Remove using a gardening tool or high pressure stream of water.

For more information on slime molds and other turf diseases, see Turfgrass Diseases in Georgia: Identification and Control

Slime molds elsewhere:

Dog vomit slime mold, Sandra Jensen, Cornell University

Other slime molds form irregularly shaped ‘blobs’ that grow on mulch, turf or other areas with organic matter. Read more about these in the publication, The Truth about Slime Molds, Spanish Moss, Lichens and Mistletoe

Also find pictures of various slime molds here.

Unusual growths on the leaves of an oak tree

November 30, 2015June 16, 2014 by Willie Chance

These are cynipid leaf galls on an oak tree leaf

To read more about these and other insect pests on trees, read the publication Forest Health Guide for Georgia.

Galls are abnormal vegetative growths on trees that result from the feeding and egg laying activities of various insects and mites. Chemical secretions from the adults while laying eggs as well as the saliva from the feeding larvae cause the plant to react abnormally.

The more common gall producers on trees are aphids, beetles, jumping plant lice, midges, mites and wasps. Each species causes a swelling of plant tissue that is characteristic on specific plant parts such as the stem, twig, leaf or petiole. Most often the gall is more readily identified than the gall producer. It is convenient to identify galls and their producers simply by noting where the gall is located and also the shape of the gall. Table 2 on page 43 of the Forest Health Guide for Georgia lists some of the more common trees that are frequently attacked by gall producers along with a description and location of the gall.

Generally galls are not life threatening to trees. Oftentimes the most drastic effects are premature leaf fall and dieback of several smaller branches.

On small trees, galls should be pruned and destroyed. Leaf and twig litter that is on the ground around the base of the tree should be raked and disposed of. A few of the common species are shown in the images included here.

For information on galls, see page 42 of the publication Forest Health Guide for Georgia. This publication is produced by the Georgia Forestry Commission.

Other galls include:

Galls on black cherry, Andy Boone, South Carolina Forestry Commission, Bugwood.org

Can you identify and control this troublesome weed?

November 30, 2015June 6, 2014 by Willie Chance

Info taken from the publication Virginia Buttonweed Identification and Control in Turfgrass by Patrick McCullough and Jialin Yu, UGA Department of Crop and Soil Sciences

Virginia buttonweed (Diodia virginiana L.) is a troublesome broadleaf weed in turfgrass throughout the southeastern United States. Virginia buttonweed is a deep-rooted perennial with prostrate or spreading branches. It usually proliferates in moist to wet areas and can tolerate mowing heights as low as one-half inch. The species is a member of the Rubiaceae family and is found from New Jersey, west to Missouri and south into the Gulf Coast states.

Virginia buttonweed leaves are slightly thickened, opposite without petioles and slightly rough along the margins (Picture 1). Leaves are green on the upper surface, light green on the lower surface and often have a mottled yellow mosaic appearance caused by a virus that commonly infects foliage (Picture 2). Branched stems are occasionally hairy (Picture 3) and reproduction occurs via seeds, roots or stem fragments. Flowers are white with four star-shaped petals, which sometimes have pink streaks in the center and two sepals. Fruit are green, elliptically shaped, hairy and ridged.

For info on managing this weed:

See entire publication

Or see sections of the publication on:

Pest Professional Pop Quiz

November 30, 2015May 12, 2014 by Willie Chance

Image taken from publication - Management of Pest Insects in and Around the Home — Image taken from publication “Management of Pest Insects in and Around the Home”

Drain flies (Psychodidae: Psychoda spp.): Also referred to as moth flies.

Taken from Management of Pest Insects in and Around the Home

Oblong or oval, appears moth-like, and is about 3/16 inch, wings fuzzy. Larvae up to 3/8 inch.

Habits: Commonly found in bathrooms (breeds in scum in drains, showers, overflows, toilet bowls, etc.). Adults rest motionless on walls until disturbed, and then fly well. Need wet conditions to breed. When toilets have gone un-flushed for an extended period, moth flies may lay eggs in the toilet tank, and larvae can be found there. When the toilet is finally flushed, larvae can make their way into the toilet bowl, where they are discovered.

Interventions: Clean the inside of the drain of all scum and detritus using a mild cleanser and a bristled brush. Never pour insecticides into drain. Pouring bleach into drains is not effective. Make certain that the water trap in the drain line (especially common in less frequently used sinks) is filled – if the water trap dries out, flies and other pests that live in the drain lines will be able to enter the building. To help determine whether a particular drain is infested, place a clear cup,
inverted, over the drain. If flies emerge from the drain, they will be trapped by the cup, and can be seen.

Might Be Confused With: fungus gnats, humpbacked flies, fruit flies, and small moths.

Pest Management Popquiz

November 30, 2015April 30, 2014 by Willie Chance

Taken from the publication Stored Product Pests in the Home by Daniel R. Suiter, Michael D. Toews, and Lisa M. Ames, UGA Department of Entomology

Indianmeal moth

The Indianmeal moth, Plodia interpunctella, is the most common stored product pest in homes, where it infests bird seed, breakfast cereals, and other consumables. Indianmeal moths are most commonly found infesting food items in kitchen cupboards, but adults may be found throughout the home because they are excellent fliers and readily disperse from the food item they are infesting. Adults may be found well-away from the larval food source.

Adult Indianmeal moths are distinctive in appearance. Their wings are bi-colored, and alternate between beige and copper (Figure 1). Moths are most active at dusk, when they can be seen (indoors) flying while searching for mates and food. During the day, moths can be found resting motionless on walls and ceilings, often near their larval food source. Adults are shortlived and do not feed.

Indianmeal moth larvae, just before they pupate, are approximately 5/8 inch long, cylindrical, and dirty-white to a faint pink or green color (Figure 1B). Larvae produce visible silk webbing in the items they infest (Figure 1C) and generally pupate close to the items they are infesting. Just prior to pupation, larvae crawl away from their feeding site to pupate at the intersection of a ceiling and wall or similar seam within the cupboard, including spaces between walls and shelves and in the tight folds of packaging. Another favorite pupation site is between the corrugations of cardboard boxes. When looking for Indianmeal moths, inspectors should look between a product’s cardboard box and liner by lifting the liner out of the box.

See this information in the original publication here.

Figure 1 B Indianmeal moth larvae (approximately 5/8 inch long and dirty-white to pink to greenish colored) often crawl away from feeding sites before they pupate.

Figure 1 C A telltale sign of Indianmeal moth infestation is the presence of silk webbing produced by larvae.

Landscape Popquiz!

November 30, 2015April 22, 2014 by Willie Chance

Spot anthracnose on dogwood

Jean Williams-Woodward, UGA Plant Pathologist

Spot anthracnose of dogwood, not to be confused with the lethal canker disease, dogwood anthracnose, is common on flowering dogwoods in the Spring. Spot anthracnose, caused by the fungus, Elsinoe corni, causes small, circular, reddish spots on the bracts and leaves. Severe infection can cause leaf and bract distortion.

Spot anthracnose is mostly an aesthetic disease. It will not kill the trees or significantly affect tree growth. Once spots are seen, it is too late to manage the disease with fungicides. Fungicides are generally not needed nor recommended unless in nurseries where tree’s aesthetics can affect sales. Fungicides needed to be applied at bud break to reduce infection and disease development.

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