The almond moth, Ephestia cautella (Walker) (Lepidoptera: Pyralidae), is a major pest of stored fruit of date palm trees, Phoenix dactylifera L. The biological performance of adult almond moths at different sex ratios (female∶male) and pairing durations (time that a male and a female were confined together) were investigated under constant conditions. The sex-ratio experiment was performed for six treatments: normal sex ratio (1F∶1M), two male-bias sex ratios (1F∶2M and 1F∶3M), two female-bias sex ratios (2F∶1M and 3F∶1M), and virgin females alone (1F∶0M). The pairing-durations experiment was performed for treatments of 1, 3, 5, 7 days, and the entire lifespan (until either the male or female died). A strong female-bias sex ratio (3F∶1M) caused a delay in the maximum number of eggs deposited from the second to the fourth day, reduced the number of laid eggs, and significantly reduced egg hatchability to 77%. A strong male-bias sex ratio (1F∶3M) significantly reduced female longevity. A pairing duration over the entire lifespan of the mating pairs significantly reduced male longevity. However, there was no significant effect on number and hatchability of eggs among different pairing duration treatments, which indicates that one day of male confinement with a female is sufficient to have optimum mating and fertilize all the E. cautella potential eggs.