Viburnum leaf
beetle home
 Sheets for recording your observations
.pdf |
.doc
Online forms to
report observations
Logo images by Kent Loeffler, Paul Weston & Craig Cramer
|
Whether you are an individual who just wants to report a viburnum leaf beetle sighting or group leader who is thinking about involving others in a large project, we welcome your involvement.
With your assistance we can learn more about the viburnum leaf beetle by:
- Tracking its current range.
- Learning which viburnum species its likes or dislikes.
- Assessing how much damage viburnum leaf beetles cause.
- Determining how weather and other factors affect its lifecycle.
Your observations will help researchers to:
- Map distribution patterns for this invasive pest.
- Gain insight into how it is moving through our landscape.
- Identify which viburnum species the beetles prefer to attack.
- Link critical periods of the pest's lifecycle to environmental factors.
- Develop an array of management tactics to reduce damage.
- Identify which management tactics effectively limit pest populations.
When do you start?
You can begin scouting for viburnum leave beetle evidence anytime, but key times for making observations are in spring (late April to early June) and midsummer (July and August).
What do you do?
- Use the resources at this website to familiarize yourself with viburnum shrubs and the viburnum leaf beetle pest. Especially review the timeline so that you know what to look for when.
- Locate one or more viburnums to observe. See The Plant for tips on where to look for viburnum shrubs and the viburnum key to make sure it is a viburnum species. This pest only attacks viburnum species.
- Inspect your viburnum shrub for the evidence of viburnum leaf beetle. Check out How to identify viburnum leaf beetles for pictures and tips on spotting evidence. You can print out the viburnum plant record sheet to record your observations in the field. Note your viburnum's location including if it in a shady or sunny spot, and most importantly if you observed evidence of viburnum leaf beetles:
- Egg-laying sites from July through April.
- Larvae from late April through mid June.
- Adults from July through October.
There may be times when you'll find more than one piece of evidence such as egg laying sites and larvae. It's also is just as important to report "none found" if that is the case.
- If you know the species of viburnum (or can figure it out using the viburnum key or other resources), note this information as well. Identifying the viburnum species is not absolutely necessary for participation. If you can't figure it out leave this question blank. Perhaps you can get someone else to help you with identification later on, or as the season progress more plant clues (such as leaves, flowers, fruit) will make identification easier. You can go back and add the species information at a later date.
- As soon as possible, report your observations using our online forms. You'll need to register the first time you enter data. Then you can simply login with your user name and password when you return to enter more data or update previously reported observations.
Do you have time for multiple visits
to your viburnum shrub(s)?
See below for suggestions about ways to help us answer important questions by visiting your viburnum at different times during the season. You can print out the viburnum plant record sheet to record your observations in the field. One sheet per viburnum shrub will likely be easiest. Be sure to report your additional observation day(s) by revisiting your online forms.
Hatching Out
If you were able to first check your viburnum before early May leaf expansion and you found egg laying sites and you were willing to leave a couple infested twigs on the shrub you might be able to pinpoint and relay to us the exact date of larvae emergence (hatching out). Multiple visits directly after the leaves begin to open will likely be necessary. The exact time of the hatch will probably vary with how quickly it warms up in spring at the particular site you are observing. If it warms up earlier than usual in spring, start looking for larvae earlier. Or if it's a cold spring, the hatch might be later than expected. Likewise, you can expect hatches earlier in warmer parts of the state, and later where it's colder.
Researchers use a measure of accumulated warmth called Growing Degree Days (GDDs for short) to help predict events such as the hatching of insects. Viburnum leaf beetles are thought to start hatching when a site has received about 100 GDDs. Visit this map to see how many GDDs have accumulated at a location near you. (Optional: If you can track the daily maximum and minimum temperatures at your site, you can calculate the precise GDDs for your site. See GDD calculation directions.)
This hatching information could help researchers begin to predict when the larvae will emerge each spring and prepare for a well-timed intervention to knock the larvae population back. Once you noted the larvae have begun to emerge you can prune out and destroy those infested twigs and leaves.
Adult Immigration
If you were able to first check your viburnum some time between late April and early June, and your thorough examination of the twigs & leaves revealed no evidence of egg laying sites or larvae, a good time to revisit your viburnum shrub is after late July. Look for adults beetles that have moved in from elsewhere and are now feeding on leaves or laying eggs on your previously uninfested viburnum. Multiple visits in late July through August might allow you to pinpoint and relay to us the exact date of your first invasion.
Management Tactics
If you were able to first check your viburnum some time between late April to early June and chose to prune out and destroy infested twigs and/or spray a chemical or use some other method to reduce the feeding larvae population, revisit your viburnum and report any change in status. Did pruning out twigs result in few to no larvae and little to no feeding damage? Were you able to knock back the larvae and limit leaf damage? Did new adults migrate in?
Neighborhood viburnum survey
If your feeling particularly interested in maximizing your contribution, the more viburnums shrubs we hear about the better. Perhaps you would even consider canvassing the neighborhood, the local public green space and natural areas for viburnum shrubs and evidence of this invasive pest. Copies of our wanted poster or flyer could be shared with neighbors. (See links from our news page for more flyer and poster options.)
If you have any questions, don't hesitate to contact project coordinator Lori Brewer, ljb7@cornell.edu.
© Copyright, Department of Horticulture, Cornell University.
Project coordinator: Lori Brewer, ljb7@cornell.edu
Website design: Craig Cramer cdc25@cornell.edu
Mention of trade names and commercial products is for educational purposes; no discrimination is intended and no endorsement by Cornell Cooperative Extension or Cornell University is implied. Pesticide recommendations are for informational purposes only and manufacturers' recommendations change. Read the manufacturers' instructions carefully before use. Cornell Cooperative Extension and Cornell University assumes no responsibility for the use of any pesticide or chemicals. Some of the links provided are not maintained by Cornell Cooperative Extension and Cornell University. Cornell Cooperative Extension and Cornell University are not responsible for information on these websites. They are included for information purposes only and no endorsement by Cornell Cooperative Extension or Cornell University is implied. Cornell Cooperative Extension provides equal program and employment opportunities.
|
