Oviposition Behavior of the Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

Female bed bugs, Cimex lectularius, in strains from three widely separated geographic regions were evaluated for diel and daily periodicity in oviposition, as well as for the duration of oviposition per se and apparent egg marking behavior. Females that were mated and fed for the first time and laying their first clutch of eggs and females fed a second time before laying their second clutch of eggs both oviposited preferentially in the scotophase of a 14:10 L:D cycle. Oviposition began before the photophase ended, indicating it was not induced by the onset of darkness and suggesting that oviposition may be governed by a circadian rhythm. First-clutch females began to oviposit closer to the onset of darkness and 1-2 days later than second-clutch females, respectively, suggesting that first-clutch females were more strictly entrained to the L:D cycle and were still undergoing reproductive maturation. In all cases, oviposition of one clutch was finished by day 10, but the frequency distributions of eggs laid daily by first-clutch and second-clutch females, as well as those of females from the three different strains, were all significantly different. The acts of oviposition and subsequent apparent egg marking behavior (a novel observation) lasted mean durations of 4.7 s and 24.1 s, respectively. During apparent egg marking, a female would repeatedly touch the abdominal cuticle in the region of the scent glands with her metathoracic tarsi and then touch the newly laid egg while concurrently waving the tip of her abdomen back and forth across the surface of the egg.