Transcript CPHST Tools: NAPPFAST

Part 2
Model Creation
Log into NAPPFAST
at www.nappfast.org .
Then select the
Nappfast tool.
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From the ‘Action’ drop
down menu you can:
Edit: Make changes to
an existing model.
Add: Create a new
model.
Rename: Change the
name of an existing
model.
Delete: Delete an existing model.
Copy: Copy an existing model, give it a new name, and
create a new model.
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Template for the model.
The dates when the model will collect data.
The variables of the
model.
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Values differentiating
between infection and
non-infection.
Values in the legend
indicating number of
accumulative days where
conditions will favor the
development of the pest.
One can test the model.
Hit ‘Save’ to make any
changes to the model
Name to be displayed on
the maps and/or any
comments about the
construction of the
model.
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NAPPFAST MAPVIEW
Important Points

What models are used to make the
predictive maps in NAPPFAST?
Degree Day
 Infection
 Generic
 Climate matching
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Degree Day Model: Theory
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“Phenology and development of most
organisms follow a temperature dependent
time scale” (Allen 1976)
Attempts to integrate temperature and
time started 250 + years ago
Development is widely believed to follow a
sigmoid shape
Temp.

Dev.
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Degree Day Model: Theory
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Organisms have base developmental
temperature- minimum temperature below
which no development occurs
Organisms have set number of units to
complete development - physiological time:
measured in developmental units (DU) or
degree days (DD)
Parameters established from lab or field
studies
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Degree Day Model

Example: Light Brown Apple Moth
base temperature 7.5 C
requires ~640 DD to complete development
(egg, larvae, pupae, adult to egg)

Degree days are typically calculated from
average of high and low temperature for a 24
hour period above the base temperature
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Degree Day Model
Light Brown Apple Moth: Base temperature 7.5 C
640 DD for generation development
If average daily temp was 11C: 3.5 DD (11-7.5) are
accumulated and it would take 182 days at that
temperature to complete development
If average daily temp was 20C: 12.5 DD (20-7.5) are
accumulated and it would take 51.2 days at that
temperature to complete development
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P. japonica general information

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Univoltine- one generation per year
Overwinters typically as a third instar larvae
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Insect Development Database
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Model Parameters
Japanese Beetle
Stage
Overwintering stage
Low 10 C
Upper 34 C
DD in stage
First entry
second entry
3rd instar
400
0
400
Pupae
124
401
525
Adult
117
526
643
egg
140
644
784
first instar
222
785
1007
Second instar
419
1008
1427
third instar
720
1428
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Graphing tools
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Disease Infection Model

Plant pathologist
describe
interactions
between pathogen,
host and
environmental
conditions as the
disease triangle.
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Disease infection model
Infection is often the rate limiting step in an
epidemic because it requires moisture which is
often limited in terrestrial environments
Infection can be modeled by a temperature
/moisture response function - a mathematical
function that describes the response of an
organism to temperature and moisture
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Disease Infection Parameters
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Tmin = Min. temperature for infection, oC,
Tmax = Max. temperature for infection, oC,
Topt = Opt. temperature for infection, oC,
Wmin = Minimum wetness duration requirement, h
Parameters established in laboratory studies
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Temperature response function
Temperature Response
Low Topt
High Topt
1
0.8
0.6
0.4
0.2
0
0
5
10
15
20
25
30
35
Temperature C
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Temperature moisture response
function
Low Topt
High Wmin
High Topt
Low Wmin
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Sudden Oak Death,
Phytophthora ramorum
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Fungal disease in cool
wet weather.
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Currently in Western US:
California and Oregon
Source Ventana Wilderness Society
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Model Parameters
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Temperature requirement
3-28 C, 20 C optimum (Werres, 2001;
Orlikowski, 2002).
Moisture requirement
12 hours for zoospore infection (Huberli,2003)
Model description
Unpublished infection model uses Wang et al.
(1998 ) temperature response function scaled to a
wetness duration requirement.
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Multi-function Model
Allows for construction of many different
models using simple logical and
mathematical equations:
(X>A, X and Y, X or Y, X and (Y or Z),
X≥A and X≤B, A* exp(B * X), etc.)
 Some examples used to date are:
temperature exclusions (high and or low
lethal temperatures), frost free days, and
emergence dates
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