Entomology Kit Climate Data & Calculations Analysis Tutorial

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

Actual Lab data Species ASpecies B Eggs1 1 st Instar2 2 nd Instar12 3 rd Feeding 3 rd Migrating 3 Pre-Pupae Pupae Adult2 Species ASpecies B Eggs1 1 st Instar31 2 nd Instar52 3 rd Feeding 3 3 rd Migrating 4 Pre-Pupae Pupae Adult41 Adult Woman in CabinAdult Man in Cabin 3 rd Instar Migrating were the most developed larvae from Species A and 2 nd Instar were the most developed from Species B. The adult flies from each species represent those laying eggs NOT adults resulting from a full life cycle.

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 Average Temperature for the month of June Which day the adult insect from both species laid its eggs (PMI) 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 DAYAVGDEPAR- TURE FROM NORMAL HEATINGCOOLINGTOTAL WATER EQUIV SNOW-FALL, ICE PELLETS SNOW, ICE PELLETS OR ICE ON GROUND AVG SPEED (MPH) AVG SPEED (KPH) SKY COVER SUNRISE- SUNSET WEATHER OCCURENCES PEAK WIND (KPH) 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

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 Average Temperature for the month of June Which day the adult insect from both species laid its eggs (PMI) 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 Egg1 st Instar2 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 °C Egg1 st Instar2 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 Average Temperature for the month of June Which day the adult insect from both species laid its eggs (PMI) 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 Accumulated 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 Accum. Deg Hrs (ADH) = = = = =10206 Accumulated degree-hours (ADH) = Sum of degree hours at each stage = 10206

Now we will repeat the Accumulated 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 Accumulated 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 Accum. Deg Hrs (ADH) = = = = = Accumulated degree-hours (ADH) = Sum of the degree hours at each stage = 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 Accumulative degree-hours for each life stage of both species Average Temperature for the month of June Which day the adult insect from both species laid its eggs (PMI) Earliest and latest time the insects began developing

Elapsed degree-hours for each day DAYAVG Average temp for the month = 12.9◦C

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 Average Temperature for the month of June Which day the adult insect from both species laid its eggs Earliest and latest time the insects began developing

Calculating the PMI Post Mortem Interval = ADH/Average actual temp = 2688/12.9 = 208 hours (divide by 24) = 8.68 days (multiply.68*24 for hours) = 8 days, 15 hours Use the ADH from the Feeding 3 rd Instar – species A because that is the maximum amount of time needed (the ADH for 2 nd Instar – species B is only 1302 hrs)

Conclusion: Bodies have been dead for a minimum of 8 days, 16 hours DAYdegree hours THUNDERSTORM The post mortem interval was calculated to be 8 days, 16 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 = 8 days, 15 hours