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 3 rd Instar Species A, 2 nd 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 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 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.
Elapsed degree-hours for each day DA Y MAXMINAVGDEPA R- TURE FROM NORM AL HEATIN G COOLIN G TOTA L WATE R EQUI V SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH ) AVG SPEED (KPH) SKY COVER SUNRISE -SUNSET WEATHER OCCUREN CES PEAK WIND (KPH) degree hours S SE SW W ,2 W SW S S SE S ,5S T ,3,5 SW ,2S S T SW W S W SW W
Elapsed degree-hours for each day DA Y MAXMINAVGDEPA R- TURE FROM NORM AL HEATIN G COOLIN G TOTA L WATE R EQUI V SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH ) AVG SPEED (KPH) SKY COVER SUNRISE -SUNSET WEATHER OCCUREN CES PEAK WIND (KPH) degree hours S SE SW W ,2 W SW S S SE S ,5S T ,3,5 SW ,2S S T SW W S W SW W On June 20 we multiply the average temperature by 15 hours to get degree-hours for that day
Elapsed degree-hours for each day DA Y MAXMINAVGDEPA R- TURE FROM NORM AL HEATIN G COOLIN G TOTA L WATE R EQUI V SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH ) AVG SPEED (KPH) SKY COVER SUNRISE -SUNSET WEATHER OCCUREN CES PEAK WIND (KPH) degree hours S SE SW W ,2 W SW S S SE S ,5S T ,3,5 SW ,2S S T SW W S W SW W 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 3 rd Instar Species A, 2 nd 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 °CEgg1 st Instar 2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa 2121 hrs31 hrs26 hrs50 hrs118 hrs240 hrs 21 hrs *21˚C = 441 deg-hrs 31*21 = *21 = *21 = *21 = *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 °CEgg1 st Instar 2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa 2125 hrs37 hrs31 hrs60 hrs124 hrs286 hrs 25*21 = *21 = *21 = *21 = *21 = *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 3 rd Instar Species A, 2 nd 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = = 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = = =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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = = = =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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = = = =10206 Adult degree-hours = ∑ degree hours at each stage = cumulative degree hours = 10206
Now we will repeat the Cumulative degree- hours 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 °CEgg1 st Instar2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa Deg Hrs Cum. Deg Hrs = = = = = 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 3 rd Instar Species A, 2 nd 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. DAYMAXMINAVGDEPAR- TURE FROM NORMA L HEATINGCOOLIN G TOTAL WATE R EQUIV SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH) AVG SPEED (KPH) SKY COVER SUNRISE- SUNSET WEATHER OCCURENC ES PEAK WIND (KPH) degree hours cumulative degree hours S SE SW W ,2 W SW S S SE S ,5 S T ,3,5 SW ,2 S S T SW W S W SW W =657.6
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. DAYMAXMINAVGDEPAR- TURE FROM NORMA L HEATINGCOOLIN G TOTAL WATE R EQUIV SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH) AVG SPEED (KPH) SKY COVER SUNRISE- SUNSET WEATHER OCCURENC ES PEAK WIND (KPH) degree hours cumulative degree hours S SE SW W ,2 W SW S S SE S ,5 S T ,3,5 SW ,2 S S T SW W S W SW W =1051.2
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. DAYMAXMINAVGDEPAR- TURE FROM NORMA L HEATINGCOOLIN G TOTAL WATE R EQUIV SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH) AVG SPEED (KPH) SKY COVER SUNRISE- SUNSET WEATHER OCCURENC ES PEAK WIND (KPH) degree hours cumulative degree hours S SE SW W ,2 W SW S S SE S ,5 S T ,3,5 SW ,2 S S T SW W S W SW W =1360.8
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. DAYMAXMINAVGDEPAR- TURE FROM NORMA L HEATINGCOOLIN G TOTAL WATE R EQUIV SNOW- FALL, ICE PELLET S SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEE D (MPH) AVG SPEED (KPH) SKY COVER SUNRISE- SUNSET WEATHER OCCURENC ES PEAK WIND (KPH) degree hours cumulative degree hours S SE SW W ,2 W SW S S SE S ,5 S T ,3,5 SW ,2 S S T SW W S W SW W From the 20 th at 3:00PM til the 1 st at 12:00AM there were a total of 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 3 rd Instar Species A, 2 nd 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. DAYdegree hours cumulative degree hours On Day 11, the cumulative degree-hours were Species A takes 2688 degree-hours to complete development in the Feeding 3 rd Instar and begin development in the Migration stage of the 3 rd Instar. The temperature data alone suggests that the eggs were laid on the 12 th, but there was a storm then, so we know that the eggs were laid before then since flies are not active during thunderstorms. Feeding 3 rd Instar Migrating 3 rd Instar = = 5166
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. DAYdegree hours cumulative degree hours On Day 17, the cumulative degree-hours were Species B takes 1302 degree-hours to complete development in the 1 st Instar and begin development in the 2 nd Instar. 1 st Instar2 nd Instar = = 1953
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 3 rd Instar Species A, 2 nd 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 DA Y degree hours cumulative degree hours Post Mortem Interval = ∑ hours(day) = h(20) + h(19) + h(18) + h(17) … + h(11) = … + 24 = 207 hours = 8 days, 15 hours
Conclusion: Bodies have been dead for a minimum of 8 days, 16 hours DA Y degree hours cumulative degree 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 11 th, so we conjecture that the flies were active at least an hour on the 11 th 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. Post Mortem Interval = ∑ hours(day) = h(20) + h(19) + h(18) + h(17) … + h(11) = … + 24 = 207 hours = 8 days, 15 hours
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