Biological Calendars: Using Growing Degree-Days and Plant Phenology to Predict Pest Activity

Transcription

1 Biological Calendars: Using Growing 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

2 Phenology: The study of recurring biological events.

3 Phenology: the foundational science of human existence Serpent Mound Fort Ancient University of Cincinnati

4 Climate change and phenology at Walden Pond We determined that plants bloomed seven days earlier on average than they did in Thoreau s times. Miller-Rushing and Primack Global warming and flowering times in Thoreau s Concord: a community perspective. Ecology 89:

5 Climate change and phenology at Sand County, WI The mean of regressions for the 55 phenophases studied was day / yr, an overall increase in phenological earliness Bradley et al Phenological changes reflect climate change in Wisconsin. PNAS 96:

6 OARDC is part of the National Phenology Network that has documented earlier springs in NA Lilac bloom as a phenological indicator of continental-scale climate change.

7 New USDA Plant Hardiness Zone Map: much of Ohio updated to warmer zone

8 D.G. Nielsen, Ohio State University Black vine weevil now emerging 2-3 weeks earlier than in 1970 D.G. Nielsen, Ohio State University Gina Penny Multiflora rose, Rosa multiflora

9 High biodiversity in landscapes and nurseries creates IPM challenges

10 Objectives: 1. Heat Units (Growing Degree-Days) 2. Phenology and biological calendars

11 Development rate of plants and insects is temperature dependent.

12 Daily temperature readings can be used to calculate growing degree-days, which is a measure of accumulated heat.

13 Growing Degree-Days (Heat Units): GDD = Avg Temp Base Temp Max = 80, Min = 60, Base = = 20 GDD

14 Growing Degree - Day (Heat Units): Amount of heat accumulated over a specified base temperature during a 24 hour day.

15 Base Temperature: Temperature above which degree-day accumulation is calculated. Ideally, the lower temperature threshold Common base temps: 50 F, 42 F, 32 F

16 Lower Temperature Threshold: Temperature below which no growth or development occurs in the species of interest.

17 Cumulative Degree - Days: Number of degree-days accumulated during a specified time interval (i.e. since the beginning of the year).

18 Key Point: Degree-days only have meaning if base temperature and starting date are specified.

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

20 Average Method: DD = Avg Temp Base Temp Max = 70, Min = = 5 DD

21 Modified Average Method: When minimum temperature drops below base temperature, set minimum = base temp. More accurate when minimum drops below base.

22 Max = 70, Min = 40 Average Method: = 5 DD Modified Average Method: = 10 DD

23 Modified Sine Wave Method:

24 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.

25 Since plant development is temperature-dependent, phenological events of plants can also be used to track degree-days and predict pest development.

26 Hypothesis: the flowering sequence of ornamental plants can be used as a biological calendar to predict pest activity and schedule pest management appointments.

27 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.

28 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).

29 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

30 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.

31 Red maple, Acer rubrum

32 Corneliancherry Dogwood, Cornus mas

33 Border Forsythia, Forsythia x intermedia Star Magnolia, Magnolia stellata

34 Eastern tent caterpillar egg hatch

35 Bradford Callery Pear, Pyrus calleryana Bradford Saucer Magnolia, Magnolia soulangiana

36 European pine sawfly egg hatch

37 Serviceberry, Amelanchier grandiflora PJM Rhododendron, Rhododendron x PJM

38 Spruce spider mite egg hatch

39 Redbud, Cercis canadensis

40 Gypsy moth egg hatch

41 Crabapple, Malus spp.

42 Koreanspice Viburnum, Viburnum carlesi

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44 Birch leafminer adult emergence

45 Common lilac, Syringa vulgaris

46 Pine needle scale egg hatch

47 Black cherry, Prunus serotina

48 Optimal timing for aerial Bt applications for gypsy moth

49 Miss Kim Lilac, Syringa patula Miss Kim

50 Oystershell scale egg hatch

51 Black locust, Robinia pseudoacacia

52 Emerald Ash Borer: Agrilus planipennis June 2006 August 2009

53 Multiflora rose, Rosa multiflora

54 Black vine weevil adult emergence

55 Black vine weevil phenology in field nurseries: the key to effective management

56 Mountain-laurel, Kalmia latifolia

57 Twospotted Spider Mite

58 Littleleaf Linden, Tilia cordata

59 Japanese Beetle

60 Key premise: phenological sequence remains constant from year-to-year.

61 How accurate is a sequence that was developed in another region?

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