Influence of Parental Age on Reproductive Potential and Embryogenesis in the Pepper Weevil, Anthonomus eugenii (Cano) (Col.: Curculionidae)

Abstract

The pepper weevil (Anthonomus eugenii Cano) is a devastating pest that inflicts severe damage to pepper crops, leading to substantial economic losses. This study investigated the impact of aging on the reproductive success of the pepper weevil. Pepper weevil-infested fruit were harvested from pepper fields and subsequently transferred into an insect cage to facilitate the emergence of adults. The emerged adults were housed in separate cages and allowed to mature until they reached specified ages: 10 days old (young), 20 days old (middle-aged), and 30 days old (old) individuals. Eggs laid by each age group were carefully collected and incubated under controlled laboratory conditions (28 ± 1.5 °C). Several reproductive variables including the number of eggs laid, the percentage of hatched eggs, and the egg incubation period were recorded for each age group. Embryonic development was also monitored daily using a VHX digital microscope at a magnification of 200×. Differences in developmental stages such as the blastoderm, germ band, gastrulation, segmentation, and appendage formation were observed, and the time span of every stage was recorded. The results show that the 10-day-old weevils laid the most eggs and had the highest hatching rate and the shortest developmental time. The 30-day-old weevils laid the fewest eggs and had the lowest hatching rate and longest developmental time. Thus, the pepper weevil age significantly influenced the fecundity, length of time for each embryonic development stage, hatching rate, and incubation period, and should be considered when studying the reproductive biology of this pest insect. This first report of the effect of aging on the reproductive potential of the pepper weevil should enable pepper growers to adopt cultural practices aimed at reducing the pepper weevil populations, thereby helping to protect their crop from this important pest.