Suppose that a lizard species eats only one type of insect and the populations follow Lotka‒Volterra dynamics. The intrinsic growth rate of insects in the absence of predators is 0.2 per week, and the mortality rate of the lizards in the absence of insects is 0.05 per week. The capture efficiency rate is 0.002, and the efficiency at which insect biomass is converted into predator biomass is 0.2.The lizard population will increase only if the number of insects is
A) above 125.
B) above 500.
C) above 625.
D) below 125.

Question

Quizplus · Accepted Answer

The lizard population will increase only if the number of insects is above 125. This is because the intrinsic growth rate of insects in the absence of predators is 0.2 per week, and the mortality rate of the lizards in the absence of insects is 0.05 per week. The capture efficiency rate is 0.002, and the efficiency at which insect biomass is converted into predator biomass is 0.2. Therefore, the number of insects that the lizards need to eat in order to maintain their population is 0.05 / 0.2 * 0.002 = 125.

Suppose That a Lizard Species Eats Only One Type of Insect