LONG-TERM COST OF REPRODUCTION WITH AND WITHOUT ACCELERATED SENESCENCE IN CALLOSOBRUCHUS-MACULATUS - ANALYSIS OF AGE-SPECIFIC MORTALITY

Age-specific mortality is measured to characterize the costs of reprod uction in the beetle Callosobruchus maculatus, providing explicit deta ils of the timing, duration, magnitude, and acceleration of mortality. We experimentally manipulated reproductive effort in four cohorts of 200 individually housed females by controlling exposure to males and t o an artificial oviposition substrate. We demonstrate that (1) early r eproduction produces long-term increases in age-specific mortality; (2 ) egg-laying effort affects the onset of age-specific mortality but no t its shape or rate of change; and (3) mating with subsequent reproduc tion increases the rate of change in age-specific mortality relative t o virgins. Accelerated senescence is defined demographically as an inc rease in the rate of change of age-specific mortality. Our results cha llenge the hypothesis that reproductive effort accelerates senescence but provides evidence that mating itself may have this effect.