Entomology Kit Climate Data Analysis Tutorial Vandalia Science Education Updated 2/22/11

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 The collection time was 3:00PM on June 20, this tells us to multiply the first average temperature by 15 hours instead of 24 Every other daily average temperature in the month will be multiplied by 24 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

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 table. Temp °CEgg1 st Instar 2 nd InstarFeeding 3 rd Instar Migrating 3 rd Instar Pupa *21 = *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 *21 = *21 = *21 = *21 = *21 = *21 = 6006

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 = = = = = Adult degree-hours = ∑ degree hours at each stage = cumulative degree hours = 10206

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

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, multiply the number of hours by the average temperature that day. 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

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

Conclusion: Bodies have been dead for a minimum of 8 days, 16 hours DA Y degree hours cumulative degree hours THUNDERSTORM Post Mortem Interval = ∑ hours(day) = h(20) + h(19) + h(18) … h(10) = 207 hours = 8 days, 15 hours 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 at the flies were active at least an hour on the 11th, 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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