Kentucky Pest News Newsletter


Number 1002__________September 22, 2003




By Ric Bessin

Coddling moth Traditionally, codling moth has been the key pest in apples in Kentucky. Apple producers design their insect pest management programs around control of this pest. At the end of the season if growers find any worm damaged fruits, it is usually attributed to codling moth. But this year, in two central Kentucky orchards, codling moth has taken a back seat to another pest that also causes wormy fruit, Oriental fruit moth.

The Oriental fruit moth is one of the most serious pests of peaches in Kentucky. Early in the season, this insect damages succulent terminal growth and attacks fruit in mid summer. Although there can be six or more generations each year, it is the second and third generations which cause most of the damage to peaches. But the late-season generations can will attack apple fruits leading up to harvest.

oriental fruit moth Larvae of subsequent generations feed on fruit, when available, and twigs. As the twigs harden, the partially grown larvae leave them and enter the fruits to feed. Larvae commonly bore right to the center of the fruit and feed around the pit. Occasionally, the larva may tunnel into the fruit through the stem. In such instances there may not be any apparent evidence of how the larvae entered the fruit after it was harvested. The larva pinkish white with a brown head and is 1/2 inch long when full grown. Although they are smaller, they appear nearly identical to codling moth larvae. An Oriental fruit moth larva feeding on the fruit often causes it to drop. These wounds also serve as sites for development of rots. Young fruit often exude gum from the entrance and exit holes left by the larvae. Damaged fruit that remain on the tree are distorted.

Apple producers with significant Oriental fruit moth damage will need to use pheromone traps to monitor for moth activity next year. These traps are used to help growers will time insecticide sprays targeting this pest. Another option that works well with this pest is mating disruption in orchards of 5 acres or more.



By John Hartman

Mushroom That is the question. It is one we frequently hear in fall, especially this fall, with its extended pleasant weather following a very moist growing season. Mushrooms grow and fruit in fields, forests and landscapes throughout Kentucky almost any time of year, but fall is an especially good time to see a diverse number of these common, often ephemeral life forms. As we savor or labor in our landscapes or hike through forests and fields enjoying the fall colors, a great variety of mushrooms can be seen growing on the ground, in landscape mulch, in the duff on the forest floor, or out in the open meadow. They are also commonly seen on decaying logs, dead branches, and even on live trees. For many people, there is a great temptation to gather and eat these fruiting bodies of fungi that we call mushrooms, toadstools, brackets, or conks.

The most frequent answer we give to the question "To eat or not to eat?" is "NO, do not eat wild mushrooms!" Most of us do not have sufficient expertise to tell the poisonous ones from the edible mushrooms. Even when a sample is submitted to the plant disease diagnostic laboratory and those of us in the lab are pretty sure of the mushroom's identity and that it is edible, we still say no. Who knows if the specimen we examined is the same as, or is representative of, what the mushroom hunter is gathering and eating? Similarly, we suggest that County Extension Agents giving advice to mushroom hunters just say no when it comes to fungal edibility.

Fungi which form mushroom-like fruiting bodies are a diverse group of organisms that grow mostly as saprophytes, but sometimes as parasites or as symbionts. As saprophytes, fungi are sometimes regarded as the vultures of the plant world, scavenging on already dead plant material and breaking the complex plant structures into humus, thus recycling dead plants into the soil for future use. For most of their lives, mushroom fungi grow as fine threads of hyphae throughout the decaying vegetable matter, decomposing wood, or sometimes the live tree that is their home. With the need to reproduce and spread spores for new colonization of the fungus, these organisms produce interesting mushrooms which are sometimes tasty and sometimes deadly poisonous. Mushrooms do not need to be eaten - they can be simply enjoyed for their beauty and diversity.

Mulch, in the landscape, especially wood chips used as a ground cover or to protect trees, is a good substrate for a variety of mushrooms. But mushrooms can emerge out of the lawn or even the driveway in the absence of visible decaying vegetable matter. In such cases, the fungi are growing on decaying wood or dead tree roots buried in the ground. Some mushrooms such as mycorrhizal fungi growing in the lawn are symbiotic with live roots, the symbiosis benefitting both the fungus and the tree. Still others growing from the roots, the base of the tree trunk, or even up on the trunk and limbs may be parasites in the process of killing their host.

Mushrooms with typical stalks and caps are often found growing in the lawn, sometimes in circles called fairy rings. Also sometimes referred to as toadstools, these fungi also grow from buried organic material such as a decaying root. Other mushrooms such as the shoestring root rot fungus grow at the base of trees infected with root and butt rot. Another fungus, called the dead man's fingers, grows as hard, black projections resembling a mummified hand from the roots of live trees in the lawn. The dead man's fingers fungus also causes root rot disease. And yes, some toadstools are so tough they push their fruiting bodies right up through an asphalt driveway. Growing on wood or organic material buried beneath the drive, in their struggle for survival they can damage property. In the meadow, giant puffballs are among the most spectacular of mushrooms. These white spheres, often baseball-sized, may grow to the size of a basketball. Mature puffballs will emit a cloud of powdery brown spores through an opening in the top when prodded. If this mushroom is harvested early, when the flesh is still white, it is edible. In the forest one can observe everything from large, rigid conks on trees to petite little fungi resembling tiny parasols or teacups growing on the humus of the forest floor.

Thus, mushrooms are an important part of the awe and wonder of nature that is present in the wild and even in our own yards. They are mostly helpful in the natural scheme of things, keeping dead plant material from accumulating to intolerable levels. Although some mushrooms can be eaten, mushrooms can also be enjoyed just for being fungi - for their uniqueness, variety, and unusual life habits.

If mushrooms are to be eaten, mushroom hunters must know for sure what species they are preparing because both poisonous and non-poisonous species can closely resemble on another. Consult with experts who have experience in identifying edible mushrooms. One can learn from experts who organize mushroom forays for avid amateurs and naturalists each fall. There are also numerous books on mushroom identification such as: Mushrooms Demystified by David Arora, Mushrooms of North America by Orson K. Miller, Jr., Mushrooms and Other Fungi of Land Between the Lakes by W. J. Sundberg and J. A. Richardson, Introduction to Mushroom Hunting by V. K. Charles, Audubon Society Field Guide to North American Mushrooms by G. H. Lincoff, and Common Fleshy Fungi by C. M. Christensen.

By Lee Townsend

Boxelder bug Boxelder bugs are common insects that feed on sap from leaves, twigs, and seeds of boxelders, as well other members of the maple family. Large numbers of them accumulate in the fall and can be seen on tree trunks, or branches, or sunning themselves on the south or west sides of buildings. This harmless accidental invader may be a temporary nuisance as it moves into sheltered sites to spend the winter.

Adult boxelder bugs are elongate, 1/2 inch long insects with sucking mouthparts. They are mostly black with some red markings. There are three narrow red lines on the segment behind the head, one down the center and one on each side and a thin red inverted "V" about the middle of the back. The wingless immature or nymphal stage has a black head, antennae, and legs. The red abdomen has an orange-yellow stripe and spot down the center of the back.

Boxelder bugs feed on plants during the summer. They move to sheltered areas (including nearby houses and buildings) in the fall and remain there during the winter. Sweep or vacuum up and discard those found inside. They will not multiply nor will they infest any household articles. These insects are only a nuisance or accidental invader; however, they may leave an odor and stain when crushed.

Exclusion is important in reducing numbers that get indoors. Check door sweeps and places outside the house that may allow them to get inside. If large numbers are present every year, removal of female boxelder plants should be considered because this is the major host plant for them. Other alternatives include controlling insects while they are on the boxelder plant or direct sprays of congregations of the insects on outside walls. Insecticidal soap provides a safe control alternative but it must be sprayed directly on the insects to be effective



By Julie Beale and Paul Bachi

Last week in the Diagnostic Laboratory, we diagnosed ear rot (Diplodia, Penicillium) and gray leaf spot on corn; potash deficiency, soybean cyst nematode, sudden death syndrome, and downy mildew on soybean; and blue mold, frogeye leaf spot, black shank, ragged leaf spot, Fusarium wilt, and calcium deficiency on tobacco.

On fruits and vegetables, we diagnosed Sphaerulina leaf spot on raspberry; Phomopsis leaf blight on strawberry; frogeye and flyspeck on apple; Cercospora leaf spot and Phoma stem canker on asparagus; Rhizoctonia root rot and Phytophthora stem blight on pepper; Phytophthora fruit blight on winter squash; root knot nematode on potato; and Septoria leaf spot and yellow shoulders on tomato.

On ornamentals and turf, we saw southern blight on dusty miller; impatiens necrotic spot virus on hosta; tomato spotted wilt on rudbeckia; Pythium root rot on chrysanthemum; leaf roller on viburnum; anthracnose on bentgrass; and gray leaf spot, and Rhizoctonia root rot on ryegrass.



Scout Cat


By Patty Lucas, University of Kentucky Research Center

UKREC-Princeton, KY, September 5 - 12, 2003
Black cutworm 2
True armyworm 2
Fall armyworm 5
European corn borer 1
Southwestern corn borer 0
Corn earworm 37

UKREC-Princeton, KY, September 12 - 19, 2003
Black cutworm 2
True armyworm 1
Fall armyworm 3
European corn borer 1
Southwestern corn borer 1
Corn earworm 28

NOTE: Trade names are used to simplify the information presented in this newsletter. No endorsement by the Cooperative Extension Service is intended, nor is criticism implied of similar products that are not named.

Lee Townsend
Extension Entomologist