Oviposition, emergence, female progeny, and development of boll weevils were determined at five different photoperiods (24:0, 14:10, 12:12, 10:14 and 0:24 h) in the laboratory. Circadian rhythms of oviposition and emergence were not affected by the photoperiods. We observed that 51.0-66.6% of their eggs were deposited between 0700-1500 h, 19.1-27.8% between 1500-1900 h, and 13.1-18.1% between 1900-0700 h during a 24 h period. The fecundities at 24, 14, or 12 h photophases were 6.6-7.2 eggs/female/day, which was significantly higher than those (2.3-4.0 eggs/female/day) at 10 or 0 h photophases. At 24, 14, or 12 h photophases female progeny were 3.2-fold higher and development time 1.7-fold shorter than those under 10 or 0 h photophases. We also observed that 54.6-71.9% of adults emerged between 0700-1900 h in all photoperiods tested.