kentucky pest news, march 11, 2014

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KENTUCKY PEST NEWSENTOMOLOGY • PLANT PATHOLOGY • WEED SCIENCE

Online at: www.uky.edu/KPN

Number 1369 March 11, 2014

FRUIT

Backyard Fruit Spray Guides Nicole Ward Gauthier, Extension Plant Pathologist

As the weather warms, questions regarding backyardfruit production are likely to arise. In response,Extension Specialists in Plant Pathology,Entomology, and Horticulture have co-authored a

simplified backyard peach spray schedule tocomplement last year’s backyard apple spray

schedule. Both documents, as well as other plantdisease factsheets, can be found on the plant

pathology publication page at

http://www2.ca.uky.edu/agcollege/plantpathology/extension/pubs.html

Here are links to the backyard fruit pubs:

• Simplified Backyard Peach and Stone FruitSpray Guide (PPFS-FR-T-20)http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-FR-T-20.pdf

• Simplified Backyard Apple Spray Guides

(PPFS-FR-T-18)http://www2.ca.uky.edu/agcollege/plantpatholog

y/ext_files/PPFShtml/PPFS-FR-T-18.pdf

• Simplified Fungicide Guide for Backyard Fruit

(PPFS-GEN-08)http://www2.ca.uky.edu/agcollege/plantpatholog

y/ext_files/PPFShtml/PPFS-GEN-08.pdf

SHADE TREES & ORNAMENTALS

Polar Vortex Effect Varies With InsectLee Townsend, Extension Entomologist

Unusual blasts of polar air swept across Kentuckythis winter. What was the effect on Kentucky

arthropods? These creatures are a hardy lot witheffective mechanisms that allow them to survive

some harsh conditions. First, a few species arevulnerable but many are not likely to be affected.Second, the air temperatures stated in weather reports

are often quite different from those occurring in siteswhere these creatures are spending the winter.

Factors such as snow cover, mulch, and orientationcan provide enough protection to allow survival.Even the impact on species that are affected can betemporary because of the high reproductivecapability of arthropods.

Here are some observations and reports on some of

our common species. Time will tell if they reflectwhat actually happened.

Lexington, KY 40546

FRUIT-Backyard Fruit Spray Guides

SHADE TREES & ORNAMENTALS

-Polar Vortex Effect Varies With Insect

http://www.uky.edu/KPN






http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-FR-T-20.pdf






http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-GEN-08.pdf














Eastern tent caterpillars

There was little apparent effect on the eastern tent

caterpillar (ETC). This insect spends the winter astiny, fully developed caterpillars in distinctive egg

masses that encircle twigs of wild cherry and relatedspecies. ETC is one of the first insects to become

active in the spring and is well-adapted to surviveour often-erratic winter and early spring weather.Hardy may be too mild a term for them. Laboratory

studies have shown that caterpillars in the egg can

withstand temperatures down to minus 31° F. It has been a cold winter, but temperatures have not been

low enough to expect a significant reduction in egghatch this spring. Dissections of some eggs collected

in early March of this year show nearly 80%survival, the same rate determined several years agoin studies by UK entomology researchers during the

ETC/Mare Reproductive Loss Syndrome outbreak.

The growth and development of many insects isdirectly dependent on temperature. Usually, thisallows relatively accurate predictions of egg hatchand development. Unfortunately, the ETC is anexception. Predictive models using degree-day

information can provide a general idea of when egghatch can occur but actual hatch in the field isvariable. In fact, eggs from a single mass usuallyhatch over about a 2-week period, not all at once.This is an important survival mechanism that

protects the species from high mortality. Prolonged

egg hatch increases the chances of species survivaleven if some early caterpillars are killed by freezesor heavy rains during early spring.

Certified Arborist Larry Hanks has tracked ETC egghatch in central Kentucky since 2001. His earliest

observation was March 13, 2012; the latest was April4, 2013. Typically, the caterpillars first appearduring the second or third week of March. It is stilltoo early to provide a general prediction for 2014.

Continued cold will slow development but a string of70° F days can cause egg hatch to begin in a shorttime.

ETC populations seem to have increased over the past 5 to 7 years with numerous tents visible along

fence line wild cherry trees in some areas of thestate. Regrowth and sprouting of new trees may haveresulted in increases in host trees and the caterpillars.Watch for information on the ETC’s developmentthis spring and monitor fence lines accordingly.

ScaleA recent sample of willow oak from JeffersonCounty had live oak lecanium scale nymphs ontwigs. Soft scales, such as this one, spend the winter

on twigs and small branches. Development resumesin the spring and adults are present in early summer.The reproductive capacity of soft scales (hundreds ofeggs per female) can mean quick recovery, even ifwinter mortality is high.

Bagworms

Bagworm is a species that appear to be susceptible tocold temperatures. Research indicates that 24 hours

at minus 1° F can kill more than 75% of the eggs in a bag. Their northern distribution in the U.S. extends

to southern Michigan, indicating winter temperatureis a limiting factor for this insect. It is one speciesthat might be reduced by our winter weather.

Figure 2. Live nymphal oak lecanium scale nymph

Figure 1. Tiny ETC larva waiting in egg



Wooly adelgid

Personnel from the Office of the State Entomologistsampled hemlock woolly adelgid populations at

several locations in eastern Kentucky. Their findingsindicate very high average mortality (greater than

90%). This may be a significant setback for theinsect but a high reproductive rate and re-infestationshould mean a rebound in time. A reduction in

adelgid populations also is likely to affect survival ofthe beetle that has been introduced as a biologicalcontrol agent.

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.

Figure 3. Bagworm larvae may be reduced due to winter

weather.

Figure 4. Hemlock woolly adelgid egg sacs

kentucky pest news, march 11, 2014

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