The branch end nests of FALL WEBWORMS on many
types of trees;
the opportunity for CATTLE GRUB control
begins;
WHITE GRUB damage beginning to appear on
infested turf;
FLEA problems increase on pets;
TWIG GIRDLERS active on oaks;
more frequent encounters
with YELLOWJACKETS and HORNETS;
FOREIGN GRAIN BEETLES, especially in new homes;
WALNUT CATERPILLARS on walnut, pecan, and hickory
The following article will be of interest to some Kentucky forage producers. The article is reproduced from the Crop Observation and Recommendation Network (C.O.R.N) Newsletter and was written by Dennis Mills, Anne Dorrance, and Pierce Paul.
“Foliar fungicides have been and will be applied to corn and soybeans. There are feeding restrictions with some fungicides. Below is a brief list according to the current label. As always double check the label to be sure there are no restrictions.
Common rust is a common disease in Kentucky corn. The disease produces leaf pustules that are circular to oval, golden-brown to cinnamon brown, up to 1/8 long. An excellent image is available online at http://ipm.uiuc.edu/bulletin/article.php?id=998. Pustules become brown to black at harvest. Leaves turn yellow and dry up when severely infected. Pustules of common rust (caused by Puccinia sorghi) are common on both leaf surfaces. (For the record, pustules of the much more destructive rust called southern rust (caused by Puccinia polysora) are densely scattered on upper leaf surface, with few on lower surface. However, southern rust has not been reportedly anywhere in Kentucky or the region.)
Common rust rarely causes economical loss in field corn in Kentucky. Most hybrids in Kentucky seem to have adequate resistance levels to common rust for our conditions. Late-planted corn is more at risk than corn planted early or on-time, though my impression is that even late-planted fields usually don’t have enough disease pressure in Kentucky to justify a fungicide spray for common rust alone. Late-planted fields that have high yield potential and which are showing a mix of common rust and other leaf diseases at tasseling—gray leaf spot and/or northern leaf blight—would be more likely to benefit from a single fungicide spray at silking than a lateplanted field with common rust alone.
For information about corn pests, visit
"Insect Management Recommendations".
For more information about soybean pests, visit
"Insect Management Recommendations".
Leaf rust is reportedly severe on selected swards of Kentucky bluegrass in central Kentucky. This is a little early for severe pressure. The generally wet weather with moderate temperatures this summer have been very favorable for rust development. The disease is readily recognizable in the field from its tiny, orangish pustules of powdery spores that erupt from within the leaf blade, eventually causing leaf blades to turn yellow and dry up. The disease does not kill turf outright but can weaken it if severe.
Under Kentucky conditions, leaf rusts on cool-season
turfgrasses usually are significant problems only in
swards that are growing slowly, such as those that are low
in nitrogen (the predominant factor this season) or low in
soil moisture. Since autumn is a very important time to
fertilize swards of cool-season turfgrasses in Kentucky to
help promote root growth and overall vigor, swards that
are showing substantial levels of rust may simply need to
be fertilized after Labor Day. For particularly high- value
swards where there may be interest in spraying
fungicides, the most effective products are those that
contain azoxystrobin, mancozeb, propiconazole,
pyraclostrobin, triadimefon, or chlorothalonil (but note
that several years ago chlorothalonil lost its label for use
on residential lawns).
Cicada killer wasps are among the most impressive of the
large insects seen during a Kentucky summer. They are
out now setting up housekeeping in well-drained, lighttextured
soil in
full sun, where
vegetation is
sparse. Common
sites include along
sidewalks, in
landscaping beds,
or in lawns or
fields where the
turf is sparse. The
wasps are solitary
but in a few years,
several hundred
burrows may
develop in an area. This results in places where the wasps
are very numerous and their normal activities can be
unsettling or intimidating.
Most encounters with this species probably are with stingless males that set up territorial perches where they wait and challenge intruders that come near. These wasps may approach people who enter their “turf” but quickly lose interest and are harmless. Females, which can sting, are too busy hunting cicadas to bury in underground tunnels as food for their larvae to be bothered by humans. However, they may respond to direct disturbance of their burrows and will sting in self-defense.
Cicada tunnels usually have a distinctive U-shaped collar of loose soil around the opening. Individual tunnels are 12 to 18 inches long and may extend 6 to 12 inches deep. There are an average of 15 egg-shaped cells as side chambers to the tunnel, each containing a paralyzed cicada and a developing wasp larva. Development will be completed next year with the wasps emerging in late summer.
The presence of large numbers of cicada killers in a area is
a sign of ideal conditions for them plus an ample supply
of cicadas. Over the long term, developing a thick turf
may be the best approach to reducing wasp numbers if
that is a goal. Direct treatment of burrow openings with
Sevin dust may provide some short term control.
Wasp stings are a serious health threat to humans and
animals. Many people in the United States die each year
from allergic reactions to the venom of these insects.
Paper wasps, hornets and yellowjackets are more
dangerous and unpredictable than honeybees. Workers
foraging away from the nest are seldom aggressive, but
nests should be eliminated with great care and in a
specific manner. "Folk" remedies such as dousing nests
with gasoline or a garden hose seldom work and can
result in multiple stings.
Paper Wasps -- Paper wasps (as well as hornets and
yellowjackets) construct nests of a paper-like material
containing finely chewed wood fragments and salivary
secretions. Paper wasps typically build their umbrellashaped
nests in protected locations, such as under eaves,
gutters and ledges or in attics and outbuildings. Nests also
may be located behind shutters, or inside exterior light
fixtures, gas grills and mailboxes. Most paper wasps are
brownish or rust-colored, although one increasingly
common variety, the European paper wasp, has yellow
and black markings much like a yellowjacket. Paper
wasps have a “waist” that is very thin, however, which
distinguishes them from hornets and yellowjackets.
Paper wasps are not very aggressive, but stings can occur
when householders inadvertently disturb nests that are
hidden. If the nest is accessible, it can be eliminated rather
easily with a wasp and hornet spray sold at most retail
stores. One advantage of these formulations is that they
can be sprayed as far as 20 feet. Although it’s best to treat
all wasp nests at night, paper wasps can be eliminated
during the daytime provided you do not stand directly below
the nest during treatment. Most wasp aerosol sprays cause
insects to drop instantly. Standing directly under a nest
increases the risk of being stung. After treatment, wait a
day to ensure that the colony is destroyed; then scrape or
knock down the nest.
Hornets -- Hornets are far more difficult and dangerous to
control than paper wasps. The nests resemble a large,
gray, bloated football, which typically is attached to a tree,
bush or side of a building. Oftentimes the nest is
concealed among branches, especially in densely canopied
trees such as Bradford pear. Hornet nests may contain
thousands of wasps that are extremely aggressive when
disturbed. The nests often are located out of reach and
elimination is best accomplished by a professional pest
control firm.
Treat hornet nests at night when most insects are within the nest and less active (follow night treatment precautions discussed below for yellowjackets). A full wasp suit, sealed at the wrists, ankles and collar, is recommended. Apply an aerosol-type wasp and hornet spray or dust formulation (e.g., Sevin, Drione, DeltaDust) directly into the nest opening. Hornet nests generally have a single opening, usually toward the bottom, where the wasps enter and exit. It is crucial that the paper envelope of the nest not be broken during treatment or the irritated wasps will scatter in all directions, causing even greater problems. Following treatment, wait at least 2-3 days before removing the nest to ensure that all of the wasps are killed. If hornets continue to be seen, the application may need to be repeated.
If the nest is located away from frequently used areas, another option is to wait and do nothing. In Kentucky, wasp, hornet, yellowjacket, and bumblebee colonies die off naturally after the weather turns cold, and the paper carton disintegrates over the winter months. Yellowjackets -- Yellowjackets are probably the most dangerous stinging insects in the United States. They tend to be unpredictable and usually sting if the nest is disturbed. Yellowjacket nests are often located underground in old animal burrows (e.g., chipmunks), or beneath rocks or landscape timbers. They also build nests in walls, attics, crawlspaces, and behind exterior siding of buildings.
If the nest can be located, it often can be eliminated by applying an aerosol-type wasp and hornet spray into the opening. Insecticide dust formulations containing Sevin (sold in lawn and garden shops), DeltaDust, or Drione, are especially effective but require a hand duster to dispense several puffs of the dust into the nest opening. In lieu of a commercial duster, a workable alternative is to use a dry, empty liquid detergent bottle filled with an inch or so of dust. A few pebbles or marbles added to the bottom prevents the dust from caking, and the bottle should be shaken before dispensing. (Remember to dispose of the bottle after use, or store it away from children and pets). Dusts tend to be more effective than aerosols when the nest itself is located some distance from the entrance hole — as often occurs when yellowjackets construct nests behind exterior siding or deep within abandoned animal burrows. Insecticide dust blown into the opening penetrates farther than sprays, and the workers transport it throughout the nest.
Ideally, treatment should be performed at night, when most of the yellowjackets are in the nest and less active. Pinpoint the nest opening during the daytime, so you will remember where to direct your treatment after dark. Approach the nest slowly and do not shine the beam of your flashlight directly into the nest entrance as this may startle the wasps and cause them to fly toward the light. Instead, cast the beam to the side to illuminate the nest indirectly. If possible, place the light on the ground rather than in your hand.
When contemplating extermination of a yellowjacket or hornet nest, clients should be informed that they are entering a DANGER ZONE — there is no pest control scenario more frightening than a ‘blown’ wasp or hornet treatment. It is often prudent to refer homeowners to a professional, especially when access to the nest requires a ladder or is difficult.
Wasp, hornet and yellowjacket stings can be life
threatening to persons who are allergic to the venom.
People who develop hives, dizziness, breathing or
swallowing difficulty, wheezing, or similar symptoms of
allergic reaction should seek medical attention
immediately. Itching, pain, and localized swelling can be
reduced with antihistamines and an ice pack.
July 18-25, 2008
UKREC-Princeton, KY
| Black Cutworm
| 4
| True Armyworm
| 32
| Corn Earworm
| 266
| European Corn Borer
| 2
| Southwestern Corn Borer
| 28
| Fall armyworm
| 9
| | |
Lexington, KY
| Black Cutworm
| 2
| True Armyworm
| 102
| Corn Earworm
| 1
| European Corn Borer
| 0
| Southwestern Corn Borer
| 0
| Fall armyworm
| 1
| | |
Graphs of insect trap counts are available on the IPM web site at - http://www.uky.edu/Ag/IPM/ipm.htm. View trap counts for Fulton County, Kentucky at - http://ces.ca.uky.edu/fulton/anr/
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