Biological Calendars:

1
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 herms.2_at_osu.edu
2
Landscapes and nurseries are diverse ecosystems
3

• Objectives
• Degree-days
• Phenology and biological calendars
• OSU Phenology Garden Network
• National Phenology Network

4
Development rate of plants and insects is
temperature dependent.
5
Daily temperature readings can be used to
calculate growing degree-days, which is a measure
of accumulated heat.
6
Degree - Day Amount of heat accumulated over a
specified base temperature during a 24 hour day.
7

• Base Temperature
• Temperature above which degree-day
• accumulation is calculated.
• Ideally, the lower temperature threshold.

8
Lower Temperature Threshold Temperature below
which no growth or development occurs in the
species of interest.
9
Cumulative Degree - Days Number of degree-days
accumulated during a specified time interval
(i.e. since the beginning of the year).
10
Key Point Degree-days only have meaning if base
temperature and starting date are specified.
11

• Calculating Degree-Days
• Average method
• Modified average method
• Modified sine wave

12
Average Method DD Avg Temp Base Temp
Max 70, Min 40
70 40 2
-

50
5 DD
13
Modified Average Method When minimum
temperature drops below base temperature, set
minimum base temp. More accurate when minimum
drops below base.
14
Max 70, Min 40
Average Method
70 40 2
-

50
5 DD
Modified Average Method
70 50 2
-

50
10 DD
15
Modified Sine Wave Method
16

• 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.

17
Since plant development is temperature-dependent,
phenological events of plants can also be used to
track degree-days and predict pest development.
18
Phenology The study of recurring biological
events. The oldest science.
19
Hypothesis the flowering sequence of ornamental
plants can be used as a biological calendar to
predict pest activity and schedule pest
management appointments.
20

• The hypothesis was tested in Secrest Arboretum by
  
• monitoring over the past 7 years
• 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.

21
Key Phenological Events
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).
22
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.
23
Phenological Sequence for Secrest
Arboretum Species Event
Degree-Days Red Maple first bloom 45 Eastern
Tent Caterpillar egg hatch 92 Eastern
Redbud first bloom 197 Gypsy Moth egg
hatch 203 Snowdrift Crabapple first
bloom 214 Birch Leafminer adult
emergence 231 Common Lilac first
bloom 238 Pine Needle Scale egg
hatch 301 Vanhoutte Spirea first
bloom 309 Lilac Borer adult emergence 336 Black
Cherry first bloom 376 Euonymus Scale egg
hatch 463 Black Locust first bloom 503 Bronze
Birch Borer adult emergence 519 Mountain-laurel
first bloom 565 Juniper Scale egg
hatch 579 Littleleaf Linden first
bloom 878 Japanese Beetle adult emergence 966
24
Red maple, Acer rubrum
25
Corneliancherry Dogwood, Cornus mas
26
Star Magnolia, Magnolia stellata
Border Forsythia, Forsythia x intermedia
27
Eastern tent caterpillar egg hatch
28
Saucer Magnolia, Magnolia soulangiana
Bradford Callery Pear, Pyrus calleryana Bradford
29
European pine sawfly egg hatch
30
PJM Rhododendron, Rhododendron x PJM
Serviceberry, Amelanchier grandiflora
31
Spruce spider mite egg hatch
32
Redbud, Cercis canadensis
33
Gypsy moth egg hatch
34
Crabapple, Malus spp.
35
Common lilac, Syringa vulgaris
36
Pine needle scale egg hatch
37
When red buckeye (Aesculus pavia) blooms
Hummingbirds return
38
Black cherry, Prunus serotina
39
Optimal timing for aerial Bt applications for
gypsy moth
40
Miss Kim Lilac, Syringa patula Miss Kim
41
Oystershell scale egg hatch
42
Black locust, Robinia pseudoacacia
43
Bronze birch borer adult emergence
44
Littleleaf Linden, Tilia cordata
45
Egg hatch of soft scales
46
Key premise phenological sequence remains
constant from year-to-year.
47
http//www.oardc.ohio-state.edu/gdd
48
(No Transcript)
49
How accurate is a biological calendar developed
in one region when it is used in another? Well
soon find out.
50
The OSU Phenology Garden Network
Coordinators Denise Ellsworth Summit County
Extension Dan Herms OARDC
51
The concept a state-wide network of identical
gardens to quantify geographic patterns of
phenological and climatic variation across Ohio.
52
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 worlds oldest
science. Education provide infrastructure for
experimentation and demonstration projects.
53
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-Sharon 1347
54
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?
55

• Protocols
• Monitor plants regularly to record date
• of first and full (95) bloom, and
• number of cumulative degree-days.
• 2. Enter data promptly at website.
• Record and share your experiences.
• Be creative.
• 5. Have fun!

56
Cooperating Nurseries Cottage Gardens Herman
Losely Son Klyn Nurseries Roemer
Nursery Studebaker Nurseries Sunleaf
Nursery Willoway Nurseries
57
The National Phenology Network www.npn.uwm.edu C
oordinator Dr. Mark Schwartz University of
Wisconsin Milwaukee mds_at_uwm.edu
58
National Phenology Network Mission
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.
59
NPN Lilac Observations Syringa chinensis 'Red
Rothomagensis'
60

• Lilac Phenological Observations
• First leaf
• 95 leaf
• First bloom
• Full bloom
• End bloom

61
www.npn.uwm.edu
62
(No Transcript)
63
(No Transcript)
64
(No Transcript)
65
(No Transcript)
66
(No Transcript)
67
(No Transcript)
68
(No Transcript)
69
Full Leaf
First Leaf
widest part of leaf past tips of brown bud scales
95 of buds open
70
First Bloom
Full Bloom
at least 50 of flower clusters on the plant have
at least one open bud
at least 50 of flower clusters have all buds open
71
End of Bloom
95 of flowers have withered or dried and floral
display has ended.
72
End of Talk
95 of attention spans have withered or dried and
PowerPoint display has ended.
73
(No Transcript)