Species A - took 23 hours for the egg to reach first instar and the eggs were collected from the scene and kept at a constant temperature of 78 degrees Fahrenheit. What was the ADH at 28 hours for the 2nd instar?

Accumulated degree hour (ADH) is the given amount of thermal energy which an egg-based animal or insect requires to develop from one stage to the next of its life, especially during the incubation period.

The formula for calculating ADH is given as:

ADH = Time (hrs.) X (Average temp. – Minimum development threshold temperature).

Data and Calculations:

Number of hours for the egg to reach the first instar = 23 hours

Storage temperature of the eggs = 78 degrees Fahrenheit

Number of hours at the second instar = 28 hours

Assumed minimum development temperature threshold for eggs = 51 degrees Fahrenheit

ADH = Time (hrs.) X (Average temp. – Minimum development threshold temperature)

= 756 {28 x (78 - 51)}

Thus, the ADH at 28 hours for the 2nd instar is 756. Though, ordinarily, an egg requires 1,890 ADH (70 x 27) to grow from the first instar to the 2nd instar.

Learn more about instar development at https://brainly.com/question/11659006