Entomology Kit
Climate Data Analysis Tutorial
Vandalia Science Education
Updated November 2011
Degree-Hour Determination
A degree-hour is a unit of measure for charting insect growth. It
is just an expression for the amount of time spent at a specific
temperature.
For example, flies that are incubated at 90 degrees for one hour
will have the same level of development as those that are
kept at 45 degrees for two hours.
90 degrees * 1 hour = 90 degree-hours
45 degrees * 2 hours = 90 degree-hours
30 degrees * 3 hours = 90 degree-hours
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Elapsed degree-hours for each day
Lab Procedure 2, Step 2: Determine the number of degree hours for each day using the
weather service data. To do this, multiply the average temperature times 24 hours for
each day. This can be performed in a spreadsheet.
• Every daily average temperature in the month
will be multiplied by 24 except June 20.
• The collection time was 3:00PM on June 20,
this tells us to multiply the average
temperature on this day by 15 hours
(12:00AM through 3:00PM = 15hrs) instead of
24 hours
Elapsed degree-hours for each day
DAY MAX
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
TURE
TURE
WATER FALL,
PELLETS SPEED SPEED
COVER
OCCURENCES
FROM
FROM
EQUIV
ICE
OR ICE ON (MPH) (KPH) SUNRISENORMAL NORMAL
PELLETS GROUND
SUNSET
PEAK degree
WIND hours
(KPH)
S 18.7
1
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8
22.08
6
0
386.666667
SE 26.2
360
SW 33.3
3
17.2 9.4 12.8
-5.2
-2.9
5.6
0.0
0.19
0
0
17.2
27.52
8
5
4
20.0 10.6 13.3
-4.7
-2.6
5.0
0.0
0.28
0
0
12.3
19.68
9
1
306.666667
W 38.6
320
W 28.3
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1
17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
8.1
12.96
6
0
466.666667
SW 24.3
493.333333
S 16.7
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
6.3
10.08
8
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
13.2
21.12
8
0
466.666667
S 27.9
386.666667
SE 10.3
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
-1.9
-1.0
0.0
0.0
0.00
0
0
4.2
6.72
3
0
6
0
453.333333
S 22.7
10 25.0 12.6 16.1
8.88 14.208
386.666667
S 32.4
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
0
19.6
31.36
6
3,5
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
T
0
23.5
37.6
8
1,3,5
367.2
SW 43.8
252
S 29.8
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
0
0
14.2
22.72
7
1,2
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
0.02
0
0
10.5
16.8
8
1
290.4
S 24.5
360
SW
15 16.5 8.9 12.8
-5.2
-2.9
0.0
0.0
T
0
0
11.9
19.04
4
0
16 18.9 10.7 13.3
-4.7
-2.6
0.0
0.0
0.00
0
0
6.4
10.24
3
0
23
306.666667
W 19.2
320
S 27.2
17 16.8 9.5 12.9
-5.1
-2.8
0.0
0.0
0.00
0
0
9.5
15.2
3
0
18 19.4 10.7 16.4
-1.6
-0.9
0.0
0.0
0.00
0
0
11.1
17.76
2
0
19 19.1 10.9 15.9
-2.1
-1.2
0.0
2.8
0.00
0
0
4.6
7.36
1
0
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
20 22.0 12.8 18.4
0.4
0.2
0.0
5.0
0.00
0
0
7.4
11.84
1
0
276
Elapsed degree-hours for each day
DAY MAX
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
TURE
TURE
WATER FALL,
PELLETS SPEED SPEED
COVER
OCCURENCES
FROM
FROM
EQUIV
ICE
OR ICE ON (MPH) (KPH) SUNRISENORMAL NORMAL
PELLETS GROUND
SUNSET
PEAK degree
WIND hours
(KPH)
S 18.7
1
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8
22.08
6
0
386.666667
SE 26.2
360
SW 33.3
3
17.2 9.4 12.8
-5.2
-2.9
5.6
0.0
0.19
0
0
17.2
27.52
8
5
4
20.0 10.6 13.3
-4.7
-2.6
5.0
0.0
0.28
0
0
12.3
19.68
9
1
306.666667
W 38.6
320
W 28.3
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1
17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
8.1
12.96
6
0
466.666667
SW 24.3
493.333333
S 16.7
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
6.3
10.08
8
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
13.2
21.12
8
0
466.666667
S 27.9
386.666667
SE 10.3
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
-1.9
-1.0
0.0
0.0
0.00
0
0
4.2
6.72
3
0
6
0
453.333333
S 22.7
10 25.0 12.6 16.1
8.88 14.208
386.666667
S 32.4
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
0
19.6
31.36
6
3,5
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
T
0
23.5
37.6
8
1,3,5
367.2
SW 43.8
252
S 29.8
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
0
0
14.2
22.72
7
1,2
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
0.02
0
0
10.5
16.8
8
1
290.4
S 24.5
360
SW
15 16.5 8.9 12.8
-5.2
-2.9
0.0
0.0
T
0
0
11.9
19.04
4
0
16 18.9 10.7 13.3
-4.7
-2.6
0.0
0.0
0.00
0
0
6.4
10.24
3
0
23
306.666667
W 19.2
320
S 27.2
17 16.8 9.5 12.9
-5.1
-2.8
0.0
0.0
0.00
0
0
9.5
15.2
3
0
18 19.4 10.7 16.4
-1.6
-0.9
0.0
0.0
0.00
0
0
11.1
17.76
2
0
19 19.1 10.9 15.9
-2.1
-1.2
0.0
2.8
0.00
0
0
4.6
7.36
1
0
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
20 22.0 12.8 18.4
0.4
0.2
0.0
5.0
0.00
0
0
7.4
11.84
1
0
276
On June 20 we multiply the average temperature by 15 hours to get degree-hours
for that day
Elapsed degree-hours for each day
DAY MAX
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
TURE
TURE
WATER FALL,
PELLETS SPEED SPEED
COVER
OCCURENCES
FROM
FROM
EQUIV
ICE
OR ICE ON (MPH) (KPH) SUNRISENORMAL NORMAL
PELLETS GROUND
SUNSET
PEAK degree
WIND hours
(KPH)
S 18.7
1
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8
22.08
6
0
386.666667
SE 26.2
360
SW 33.3
3
17.2 9.4 12.8
-5.2
-2.9
5.6
0.0
0.19
0
0
17.2
27.52
8
5
4
20.0 10.6 13.3
-4.7
-2.6
5.0
0.0
0.28
0
0
12.3
19.68
9
1
306.666667
W 38.6
320
W 28.3
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1
17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
8.1
12.96
6
0
466.666667
SW 24.3
493.333333
S 16.7
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
6.3
10.08
8
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
13.2
21.12
8
0
466.666667
S 27.9
386.666667
SE 10.3
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
-1.9
-1.0
0.0
0.0
0.00
0
0
4.2
6.72
3
0
6
0
453.333333
S 22.7
10 25.0 12.6 16.1
8.88 14.208
386.666667
S 32.4
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
0
19.6
31.36
6
3,5
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
T
0
23.5
37.6
8
1,3,5
367.2
SW 43.8
252
S 29.8
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
0
0
14.2
22.72
7
1,2
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
0.02
0
0
10.5
16.8
8
1
290.4
S 24.5
360
SW
15 16.5 8.9 12.8
-5.2
-2.9
0.0
0.0
T
0
0
11.9
19.04
4
0
16 18.9 10.7 13.3
-4.7
-2.6
0.0
0.0
0.00
0
0
6.4
10.24
3
0
23
306.666667
W 19.2
320
S 27.2
17 16.8 9.5 12.9
-5.1
-2.8
0.0
0.0
0.00
0
0
9.5
15.2
3
0
18 19.4 10.7 16.4
-1.6
-0.9
0.0
0.0
0.00
0
0
11.1
17.76
2
0
19 19.1 10.9 15.9
-2.1
-1.2
0.0
2.8
0.00
0
0
4.6
7.36
1
0
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
20 22.0 12.8 18.4
0.4
0.2
0.0
5.0
0.00
0
0
7.4
11.84
1
0
276
For every other day, we multiply the average temperature by 24 hours to get
degree-hours for that day
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Degree-hours for each life stage: Species A
Lab Procedure 2, Step 3: Determine the number of degree-hours required for each life
stage of both species. To do this, multiply the number of hours by the degrees Celsius
given in the life cycle table.
Temp °C
Egg
1st
Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21 hrs
31 hrs
26 hrs
50 hrs
118 hrs
240 hrs
21 hrs
*21˚C =
441
deg-hrs
31*21 =
651
26*21 =
546
50*21 =
1050
118*21 =
2478
240*21 =
5040
Degree-hours for each life stage: Species B
Lab Procedure 2, Step 3: Determine the number of degree hours required for each life
stage of both species. To do this, multiply the number of hours by the degrees Celsius
given in the table.
Temp °C
Egg
1st
Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
25 hrs
37 hrs
31 hrs
60 hrs
124 hrs
286 hrs
25*21 =
525
37*21 =
777
31*21 =
651
60*21 =
1260
124*21 =
2604
286*21 =
6006
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
546+1092
= 1638
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
546+1092 1050+1638
= 1638
= 2688
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
546+1092 1050+1638
= 1638
= 2688
2478+2688
=5166
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
546+1092 1050+1638
= 1638
= 2688
2478+2688
=5166
5040+5166
=10206
Cumulative degree-hours for each life stage:
Species A
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
21
31
26
50
118
240
Deg Hrs
441
651
546
1050
2478
5040
Cum.
Deg Hrs
441
651+441
= 1092
546+1092 1050+1638
= 1638
= 2688
2478+2688
=5166
5040+5166
=10206
Adult degree-hours = ∑ degree hours at each stage
= cumulative degree hours
= 10206
Now we will repeat the Cumulative degreehours calculation for Species B
Cumulative degree-hours for each life stage:
Species B
Lab Procedure 2, Step 4: By adding all the degree hours for each of the six life stages
together, you calculate the cumulative degree hours required for an adult fly to develop
at 21°C.
Temp °C
Egg
1st Instar
2nd Instar
Feeding 3rd
Instar
Migrating
3rd Instar
Pupa
21
25
37
31
60
124
286
Deg Hrs
525
777
651
1260
2604
6006
Cum.
Deg Hrs
525
777+525
= 1302
651+1302 1260+1953
= 1953
= 3213
2604+3213
= 5817
6006+5817
= 11823
Adult degree-hours = ∑ degree hours at each stage
= cumulative degree hours
= 11823
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Cumulative degree-hours for each day
Lab Procedure 2, Step 5: Calculate elapsed degree hours for each of the days in the
climatological data provided. To do this, add the degree hours for each day to the one
before it starting at the 20th of the month.
DAY MAX
1
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
PEAK degree
TURE
TURE
WATER FALL, PELLETS SPEED SPEED
COVER OCCURENCES WIND hours
FROM
FROM
EQUIV
ICE OR ICE ON (MPH) (KPH) SUNRISE(KPH)
NORMAL NORMAL
PELLETS GROUND
SUNSET
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
cumulative
degree
hours
S 18.7 386.66666
7
SE 26.2
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8 22.08
6
0
3
4
17.2 9.4 12.8
20.0 10.6 13.3
-5.2
-4.7
-2.9
-2.6
5.6
5.0
0.0
0.0
0.19
0.28
0
0
0
0
17.2 27.52
12.3 19.68
8
9
5
1
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1 17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
10 25.0 12.6 16.1
-1.9
-1.0
0.0
0.0
0.00
0
0
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
14 19.3 9.3 15.0
-3.0
-1.7
0.0
15
16
17
18
12.8
13.3
12.9
16.4
-5.2
-4.7
-5.1
-1.6
-2.9
-2.6
-2.8
-0.9
19 19.1 10.9 15.9
20 22.0 12.8 18.4
-2.1
0.4
-1.2
0.2
16.5
18.9
16.8
19.4
8.9
10.7
9.5
10.7
8.1
12.96
6
0
6.3
10.08
8
0
13.2 21.12
8
0
3
0
8.88 14.208
6
0
0
19.6 31.36
6
3,5
T
0
23.5
8
1,3,5
0.23
0
0
14.2 22.72
7
1,2
0.0
0.02
0
0
10.5
8
1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
T
0.00
0.00
0.00
0
0
0
0
0
0
0
0
11.9 19.04
6.4 10.24
9.5
15.2
11.1 17.76
4
3
3
2
0
0
0
0
0.0
0.0
2.8
5.0
0.00
0.00
0
0
0
0
1
1
0
0
4.2
4.6
7.4
6.72
37.6
16.8
7.36
11.84
360
SW 33.3 306.66666
7
W 38.6
320
W 28.3 466.66666
7
SW 24.3 493.33333
3
S 16.7 466.66666
7
S 27.9 386.66666
7
SE 10.3 453.33333
3
S 22.7 386.66666
7
S 32.4
367.2
SW 43.8
252
S 29.8
290.4
S 24.5
360
SW 23 306.66666
7
W 19.2
320
S 27.2
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
276
381.6 + 276 =657.6
657.6
276
Cumulative degree-hours for each day
Lab Procedure 2, Step 5: Calculate elapsed degree hours for each of the days in the
climatological data provided. To do this, add the degree hours for each day to the one
before it starting at the 20th of the month.
DAY MAX
1
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
PEAK degree
TURE
TURE
WATER FALL, PELLETS SPEED SPEED
COVER OCCURENCES WIND hours
FROM
FROM
EQUIV
ICE OR ICE ON (MPH) (KPH) SUNRISE(KPH)
NORMAL NORMAL
PELLETS GROUND
SUNSET
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
cumulative
degree
hours
S 18.7 386.66666
7
SE 26.2
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8 22.08
6
0
3
4
17.2 9.4 12.8
20.0 10.6 13.3
-5.2
-4.7
-2.9
-2.6
5.6
5.0
0.0
0.0
0.19
0.28
0
0
0
0
17.2 27.52
12.3 19.68
8
9
5
1
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1 17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
10 25.0 12.6 16.1
-1.9
-1.0
0.0
0.0
0.00
0
0
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
15
16
17
18
12.8
13.3
12.9
16.4
-5.2
-4.7
-5.1
-1.6
-2.9
-2.6
-2.8
-0.9
0.0
0.0
0.0
0.0
19 19.1 10.9 15.9
20 22.0 12.8 18.4
-2.1
0.4
-1.2
0.2
0.0
0.0
16.5
18.9
16.8
19.4
8.9
10.7
9.5
10.7
8.1
12.96
6
0
6.3
10.08
8
0
13.2 21.12
8
0
3
0
8.88 14.208
6
0
0
19.6 31.36
6
3,5
T
0
23.5
8
1,3,5
0
0
14.2 22.72
7
1,2
0.02
0
0
10.5
8
1
0.0
0.0
0.0
0.0
T
0.00
0.00
0.00
0
0
0
0
0
0
0
0
11.9 19.04
6.4 10.24
9.5
15.2
11.1 17.76
4
3
3
2
0
0
0
0
2.8
5.0
0.00
0.00
0
0
0
0
1
1
0
0
4.2
4.6
7.4
6.72
37.6
16.8
7.36
11.84
360
SW 33.3 306.66666
7
W 38.6
320
W 28.3 466.66666
7
SW 24.3 493.33333
3
S 16.7 466.66666
7
S 27.9 386.66666
7
SE 10.3 453.33333
3
S 22.7 386.66666
7
S 32.4
367.2
SW 43.8
252
S 29.8
290.4
S 24.5
360
SW 23 306.66666
7
W 19.2
320
S 27.2
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
276
393.6 + 657.6=1051.2
1051.2
657.6
276
Cumulative degree-hours for each day
Lab Procedure 2, Step 5: Calculate elapsed degree hours for each of the days in the
climatological data provided. To do this, add the degree hours for each day to the one
before it starting at the 20th of the month.
DAY MAX
1
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
PEAK degree
TURE
TURE
WATER FALL, PELLETS SPEED SPEED
COVER OCCURENCES WIND hours
FROM
FROM
EQUIV
ICE OR ICE ON (MPH) (KPH) SUNRISE(KPH)
NORMAL NORMAL
PELLETS GROUND
SUNSET
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
6.3
10.08
6
0
cumulative
degree
hours
S 18.7 386.66666
7
SE 26.2
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8 22.08
6
0
3
4
17.2 9.4 12.8
20.0 10.6 13.3
-5.2
-4.7
-2.9
-2.6
5.6
5.0
0.0
0.0
0.19
0.28
0
0
0
0
17.2 27.52
12.3 19.68
8
9
5
1
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1 17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
10 25.0 12.6 16.1
-1.9
-1.0
0.0
0.0
0.00
0
0
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
15
16
17
18
12.8
13.3
12.9
16.4
-5.2
-4.7
-5.1
-1.6
-2.9
-2.6
-2.8
-0.9
0.0
0.0
0.0
0.0
19 19.1 10.9 15.9
20 22.0 12.8 18.4
-2.1
0.4
-1.2
0.2
0.0
0.0
16.5
18.9
16.8
19.4
8.9
10.7
9.5
10.7
8.1
12.96
6
0
6.3
10.08
8
0
13.2 21.12
8
0
3
0
8.88 14.208
6
0
0
19.6 31.36
6
3,5
T
0
23.5
8
1,3,5
0
0
14.2 22.72
7
1,2
0.02
0
0
10.5
8
1
0.0
0.0
0.0
0.0
T
0.00
0.00
0.00
0
0
0
0
0
0
0
0
11.9 19.04
6.4 10.24
9.5
15.2
11.1 17.76
4
3
3
2
0
0
0
0
2.8
5.0
0.00
0.00
0
0
0
0
1
1
0
0
4.2
4.6
7.4
6.72
37.6
16.8
7.36
11.84
360
SW 33.3 306.66666
7
W 38.6
320
W 28.3 466.66666
7
SW 24.3 493.33333
3
S 16.7 466.66666
7
S 27.9 386.66666
7
SE 10.3 453.33333
3
S 22.7 386.66666
7
S 32.4
367.2
SW 43.8
252
S 29.8
290.4
S 24.5
360
SW 23 306.66666
7
W 19.2
320
S 27.2
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
276
309.6 + 1051.2=1360.8
1360.8
1051.2
657.6
276
Cumulative degree-hours for each day
Lab Procedure 2, Step 5: Calculate elapsed degree hours for each of the days in the
climatological data provided. To do this, add the degree hours for each day to the one
before it starting at the 20th of the month.
DAY MAX
MIN
AVG DEPAR- DEPAR- HEATING COOLING TOTAL SNOW- SNOW, ICE AVG
AVG
SKY
WEATHER
PEAK degree
TURE
TURE
WATER FALL, PELLETS SPEED SPEED
COVER OCCURENCES WIND hours
FROM
FROM
EQUIV
ICE OR ICE ON (MPH) (KPH) SUNRISE(KPH)
NORMAL NORMAL
PELLETS GROUND
SUNSET
1
18.3 10.6 16.1
-1.9
-1.0
2.2
0.0
0.00
0
0
10.08
6
0
2
19.4 12.8 15.0
-3.0
-1.7
3.3
0.0
0.09
0
0
13.8 22.08
6
0
3
4
17.2 9.4 12.8
20.0 10.6 13.3
-5.2
-4.7
-2.9
-2.6
5.6
5.0
0.0
0.0
0.19
0.28
0
0
0
0
17.2 27.52
12.3 19.68
8
9
5
1
5
21.1 12.8 19.4
1.4
0.8
0.0
1.1
0.00
0
0
11.1 17.76
7
1,2
6
25.6 16.7 20.6
2.6
1.4
0.0
2.2
0.00
0
0
7
23.9 15.2 19.4
1.4
0.8
0.0
1.1
0.07
0
0
8
20.6 12.8 16.1
-1.9
-1.0
0.0
0.0
0.11
0
0
9
22.1 13.9 18.9
0.9
0.5
0.0
0.6
0.00
0
0
10 25.0 12.6 16.1
-1.9
-1.0
0.0
0.0
0.00
0
0
11 22.1 8.9 15.3
-2.7
-1.5
0.0
0.0
0.67
0
12 14.5 9.4 10.5
-7.5
-4.2
0.0
0.0
1.13
13 16.7 7.2 12.1
-5.9
-3.3
0.0
0.0
0.23
14 19.3 9.3 15.0
-3.0
-1.7
0.0
0.0
15
16
17
18
12.8
13.3
12.9
16.4
-5.2
-4.7
-5.1
-1.6
-2.9
-2.6
-2.8
-0.9
0.0
0.0
0.0
0.0
19 19.1 10.9 15.9
20 22.0 12.8 18.4
-2.1
0.4
-1.2
0.2
0.0
0.0
16.5
18.9
16.8
19.4
8.9
10.7
9.5
10.7
6.3
8.1
12.96
6
0
6.3
10.08
8
0
13.2 21.12
8
0
3
0
8.88 14.208
6
0
0
19.6 31.36
6
3,5
T
0
23.5
8
1,3,5
0
0
14.2 22.72
7
1,2
0.02
0
0
10.5
8
1
0.0
0.0
0.0
0.0
T
0.00
0.00
0.00
0
0
0
0
0
0
0
0
11.9 19.04
6.4 10.24
9.5
15.2
11.1 17.76
4
3
3
2
0
0
0
0
2.8
5.0
0.00
0.00
0
0
0
0
1
1
0
0
4.2
4.6
7.4
6.72
37.6
16.8
7.36
11.84
S 18.7 386.66666
7
SE 26.2
360
SW 33.3 306.66666
7
W 38.6
320
W 28.3 466.66666
7
SW 24.3 493.33333
3
S 16.7 466.66666
7
S 27.9 386.66666
7
SE 10.3 453.33333
3
S 22.7 386.66666
7
S 32.4
367.2
SW 43.8
252
S 29.8
290.4
S 24.5
360
SW 23 306.66666
7
W 19.2
320
S 27.2
309.6
W 26.3
393.6
SW 17.8
381.6
W 23.1
276
cumulative
degree
hours
7283.73333
6897.06667
6537.06667
6230.4
5910.4
5443.73333
4950.4
4483.73333
4097.06667
3643.73333
3257.06667
2889.86667
2637.86667
2347.46667
1987.46667
1680.8
1360.8
1051.2
657.6
276
From the 20th at
3:00PM til the
1st at 12:00AM
there were a
total of 7283.7
degree-hours
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Which day the adult insect laid eggs on
the body: Species A
Lab Procedure 2, Step 6a: Examine the species A life stages collected as evidence and
identify the oldest species A life stage collection for the adult male.
DAY degree
hours
1
cumulative
degree
hours
386.66666
7
2
Feeding 3rd
Instar
Migrating 3rd
Instar
50
118
1050
2478
1050+1638 =
2688
2478+1638 =
5166
7283.73333
360
306.66666
3
7
4
320
466.66666
5
7
493.33333
6
3
466.66666
7
7
386.66666
8
7
453.33333
9
3
386.66666
10
7
6897.06667
11
367.2
3257.06667
12
252
2889.86667
13
290.4
2637.86667
14
360
306.66666
7
320
309.6
393.6
2347.46667
15
16
17
18
19
20
381.6
276
657.6
276
6537.06667
6230.4
5910.4
5443.73333
4950.4
4483.73333
4097.06667
3643.73333
1987.46667
1680.8
1360.8
1051.2
On Day 11, the cumulative degree-hours were 3257.
Species A takes 2688 degree-hours to complete
development in the Feeding 3rd Instar and begin
development in the Migration stage of the 3rd Instar.
The temperature data alone suggests that the eggs
were laid on the 12th, but there was a storm then, so
we know that the eggs were laid before then since
flies are not active during thunderstorms.
Which day the adult insect laid eggs on
the body: Species B
Lab Procedure 2, Step 6a: Examine the species A life stages collected as evidence and
identify the oldest species B life stage collection for the adult male.
DAY degree
hours
1
cumulative
degree
hours
386.66666
7
2
7283.73333
360
306.66666
3
7
4
320
466.66666
5
7
493.33333
6
3
466.66666
7
7
386.66666
8
7
453.33333
9
3
386.66666
10
7
6897.06667
11
367.2
3257.06667
12
252
2889.86667
13
290.4
2637.86667
14
360
306.66666
7
320
309.6
393.6
2347.46667
15
16
17
18
19
20
381.6
276
657.6
276
6537.06667
6230.4
5910.4
1st Instar
2nd Instar
37
31
777
651
777+525 =
1302
651+1302 =
1953
5443.73333
4950.4
4483.73333
4097.06667
3643.73333
1987.46667
1680.8
1360.8
1051.2
On Day 17, the cumulative degree-hours were 1360.
Species B takes 1302 degree-hours to complete
development in the 1st Instar and begin development
in the 2nd Instar.
Degree-Hour Determination
Knowns
• Bodies discovered at 1:00PM on June 20
• Insects collected at 3:00PM on June 20
• Weather type (sunny, partly cloudy, overcast)
• Weather events (rain, thunderstorms, snow)
• Daily average temperature
• Male and Female had the same species and lifecycles present
(Migrating 3rd Instar Species A, 2nd Instar Species B)
Unknowns
• Elapsed degree-hours for each day
• Degree-hours for each life stage of both species
• Cumulative degree-hours for each life stage of both species
• Cumulative elapsed degree hours for each day
• Which day the adult insect from both species laid its eggs
• Earliest and latest time the insects began developing
Calculating the PMI
DAY degree
hours
cumulative
degree
hours
10
453.33333
3
386.66666
7
11
367.2
3257.06667
12
252
2889.86667
13
290.4
2637.86667
14
2347.46667
15
16
17
18
360
306.66666
7
320
309.6
393.6
19
20
381.6
276
657.6
276
9
4097.06667
3643.73333
1987.46667
1680.8
1360.8
1051.2
Post Mortem Interval = ∑ hours(day)
= h(20) + h(19) + h(18) + h(17) … + h(11)
= 15 + 24 + 24 + 24 … + 24
= 207 hours
= 8 days, 15 hours
Conclusion: Bodies have been dead for
a minimum of 8 days, 16 hours
DAY degree
hours
cumulative
degree
hours
10
453.33333
3
386.66666
7
11
367.2
3257.06667
12
252
2889.86667
13
290.4
2637.86667
14
2347.46667
15
16
17
18
360
306.66666
7
320
309.6
393.6
19
20
381.6
276
657.6
276
9
4097.06667
3643.73333
1987.46667
1680.8
1360.8
1051.2
Post Mortem Interval = ∑ hours(day)
= h(20) + h(19) + h(18) + h(17) … + h(11)
= 15 + 24 + 24 + 24 … + 24
= 207 hours
= 8 days, 15 hours
THUNDERSTORM
The post mortem interval was calculated to be 8 days, 15
hours, but we know that the storm occurred on the
evening of the 11th, so we conjecture that the flies were
active at least an hour on the 11th to give them time to lay
the eggs, thus bringing our PMI to a minimum of 8 days,
16 hours. The actual PMI, which is unknown, may vary up
to 12 hours more than this calculation due to weather.
Students’ calculations may vary by up to a day later.
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