Presentation on theme: "Biological Calendars: Using Degree-Days and Plant Phenology to Predict Pest Activity Dan Herms Department of Entomology The Ohio State University Ohio."— Presentation transcript:
Biological Calendars: Using Degree-Days and Plant Phenology to Predict Pest Activity Dan Herms Department of Entomology The Ohio State University Ohio Agricultural Research and Development Center Wooster
Landscapes and nurseries are diverse ecosystems
Objectives: 1. Degree-days 2. Phenology and biological calendars 3. OSU Phenology Garden Network 4. National Phenology Network
Development rate of plants and insects is temperature dependent.
Daily temperature readings can be used to calculate growing degree-days, which is a measure of accumulated heat.
Degree - Day: Amount of heat accumulated over a specified base temperature during a 24 hour day.
Base Temperature: Temperature above which degree-day accumulation is calculated. Ideally, the lower temperature threshold.
Lower Temperature Threshold: Temperature below which no growth or development occurs in the species of interest.
Cumulative Degree - Days: Number of degree-days accumulated during a specified time interval (i.e. since the beginning of the year).
Key Point: Degree-days only have meaning if base temperature and starting date are specified.
Calculating Degree-Days Average method Modified average method Modified sine wave
= DD Average Method: DD = Avg Temp – Base Temp Max = 70, Min = 40
Modified Average Method: When minimum temperature drops below base temperature, set minimum = base temp. More accurate when minimum drops below base.
Modified Average Method: = DD = DD Average Method: Max = 70, Min = 40
Modified Sine Wave Method:
Limitations of Degree-Day Models: Insect response to temperature is not linear. Lower temperature threshold known for very few species. Measured temperatures not the same as those experienced by the pest. Degree-days are cumbersome to track.
Since plant development is temperature-dependent, phenological events of plants can also be used to track degree-days… and predict pest development.
Phenology: The study of recurring biological events. “The oldest science.”
Hypothesis: the flowering sequence of ornamental plants can be used as a biological calendar to predict pest activity and schedule pest management appointments.
The hypothesis was tested in Secrest Arboretum by monitoring over the past 7 years: 1.The phenology of 45 key arthropod pests of ornamental plants (e.g. egg hatch, adult emergence). 2. The flowering sequence of 75 taxa of woody ornamental plants.
First bloom: date first flower on the plant opens to reveal pistils and / or stamens. Full bloom: date 95% of flowers have opened (e.g. 1 out of 20 buds remains closed). Key Phenological Events
The flowering sequence of plants can be used as a biological calendar to track degree-days and schedule pest management appointments. S. Gage, Michigan State Univ. D.G. Nielsen, Ohio State Univ.
Phenological Sequence for Secrest Arboretum Species Event Degree-Days Red Maplefirst bloom 45 Eastern Tent Caterpillaregg hatch 92 Eastern Redbudfirst bloom197 Gypsy Mothegg hatch203 Snowdrift Crabapplefirst bloom214 Birch Leafmineradult emergence231 Common Lilacfirst bloom238 Pine Needle Scaleegg hatch301 Vanhoutte Spireafirst bloom309 Lilac Boreradult emergence336 Black Cherryfirst bloom376 Euonymus Scaleegg hatch463 Black Locustfirst bloom503 Bronze Birch Boreradult emergence519 Mountain-laurelfirst bloom565 Juniper Scaleegg hatch579 Littleleaf Lindenfirst bloom878 Japanese Beetleadult emergence966
Red maple, Acer rubrum
Corneliancherry Dogwood, Cornus mas
Star Magnolia, Magnolia stellata Border Forsythia, Forsythia x intermedia
PJM Rhododendron, Rhododendron x ‘PJM’ Serviceberry, Amelanchier grandiflora
Spruce spider mite egg hatch
Redbud, Cercis canadensis
Gypsy moth egg hatch
Crabapple, Malus spp.
Common lilac, Syringa vulgaris
Pine needle scale egg hatch
When red buckeye (Aesculus pavia) blooms: Hummingbirds return
Black cherry, Prunus serotina
Optimal timing for aerial Bt applications for gypsy moth
Miss Kim Lilac, Syringa patula ‘ Miss Kim’
Oystershell scale egg hatch
Black locust, Robinia pseudoacacia
Bronze birch borer adult emergence
Littleleaf Linden, Tilia cordata
Egg hatch of soft scales
Key premise: phenological sequence remains constant from year-to-year.
How accurate is a biological calendar developed in one region when it is used in another? We’ll soon find out.
The OSU Phenology Garden Network Coordinators: Denise Ellsworth Summit County Extension Dan Herms OARDC
The concept: a state-wide network of identical gardens to quantify geographic patterns of phenological and climatic variation across Ohio.
Objective: create a standardized biological calendar Research: document short-term phenological and weather variation; long-term climate change. Outreach: predict pest emergence / fine-tune timing recommendations. Science Literacy: increase public awareness / involvement with “the world’s oldest science”. Education: provide infrastructure for experimentation and demonstration projects.
The Biological Calendar Species First Bloom (DD50) Star Magnolia 83 Forsythia 86 PJM Rhododendron 147 Koreanspice Viburnum 185 Coralburst Crabapple 217 Common Lilac 234 Vanhoutte Spirea 309 Redosier Dogwood 326 Miss Kim Lilac 423 Bush Cinquefoil 445 Red Prince Weigela 446 Arrowwood Viburnum 534 Bumald Spirea 624 Elderberry 707 Oakleaf Hydrangea 835 Rose-of-Sharon1347
Additional applications: Butterfly garden and phenology (when do monarchs return?) Bird / wildflower / mushroom phenology (when should I look for trilliums; hunt for morels?) Weed phenology (forsythia and crabgrass?) Frost-free dates (Vanhoutte Spirea?) Planting dates (forsythia and radish; lilac and beans?) Plant propagation (when to take cuttings?) Others?
Protocols: 1. Monitor plants regularly to record date of first and full (95%) bloom, and number of cumulative degree-days. 2. Enter data promptly at website. 3. Record and share your experiences. 4. Be creative. 5. Have fun!
Cooperating Nurseries: Cottage Gardens Herman Losely & Son Klyn Nurseries Roemer Nursery Studebaker Nurseries Sunleaf Nursery Willoway Nurseries
The National Phenology Network Coordinator: Dr. Mark Schwartz University of Wisconsin Milwaukee
Facilitate collection and dissemination of plant phenological data across the US Support research on interactions between plants and lower atmosphere, and long- term impacts of climate change. National Phenology Network Mission