2.5. Life table parameters
Life table parameters were calculated as follows: net repro-
ductive rate: R0 ¼ lxmx; generation time: T ¼ xlxmxx/R0;
intrinsic rate of natural increase: rm ¼ ln (R0)/T; and finite rate of
increase: l ¼ erm. Where lx was the survival rate for adults from
birth to age x; mx represented female offspring produced at age x; T
was the development time from egg to adult emergence and e is
Euler’s constant (approximately 2.7183), which is the base of nat-
ural logarithms (Birch, 1948).