Part 3: Using ADH from the Scene to Determine TOD

Dr. Krinsky used various entomological references in calculating the ADH to count back to the earliest possible time of egg laying by adult black blow flies. One of the references states that at a constant 80 degree temperature Fahrenheit, it takes between 10-12 days to go from the egg laying through the maggot and pupae stages into an adult fly.

Use the table that you previously made to answer questions 7 a-d. Record your answers on the able on your handout.

7 a. Calculate ADH at a constant 80 degrees F and fill in row A in the table on your handout.

b. Calculate the thermal heat provided at Dr. Krinsky's laboratory for the 25 flies that emerged on September 27. Go back to Part 2 and look at the laboratory work. Find the data for the 25 flies that emerged on September 27 at 4 PM. You will find the temperature there and you will need to calculate the amount of time between when the pupae were collected from the body and when they emerged as flies in hours. Use that to calculate the ADH from the laboratory to determine this number. You will use the same number in each day on row B on your handout.

c. Subtract B from A (remaining ADH value).

d. Use the information from row C and the last column in table 3 to make the best estimate of what date was the approximate date of egg laying.

Read the "Other Questions" below.

Answer the conclusion question and Analysis Questions on your handout to complete this exercise.