ARS | Publication request: Patterns and consequences of mating behavior of the Diaprepes root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae) in the field

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 22, 2008
Publication Date: September 1, 2008
Citation: Sirot, L.K., Lapointe, S.L. 2008. Patterns and consequences of mating behavior of the Diaprepes root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae) in the field. Florida Entomologist. 91:400-406.

Interpretive Summary: The root weevil, Diaprepes abbreviatus, is a major pest of citrus, sugar cane, and many ornamental plants of economic importance. It was accidentally introduced from the Caribbean into Florida in the 1960¿s and its range within the United States has now expanded to include Texas and California. Thus far, no safe and effective control method has been developed for this species. Little is known about its reproductive behavior under field conditions. Mating patterns were studied by observing the behavior of marked weevils in the field. Matings occurred throughout the day but peaked during the middle of the day. Mating duration ranged from less than three hours to over nine hours. Both males and females mated frequently, and sometimes with the same partner multiple times. We found no short-term benefits of multiple mating but we found that female fertility decreased dramatically if females are not allowed to remate. These studies shed light on the mating behavior of an important pest species and will contribute to control efforts that target key behavioral traits such as mating and aggregation. Why these root weevils spend such considerable time mating remains a mystery.

Technical Abstract: The root weevil, Diaprepes abbreviatus, is a major pest of citrus, sugar cane, and ornamental plants. It was accidentally introduced from the Caribbean into Florida in the 1960¿s and its range within the United States has now expanded to include Texas and California. No safe and effective control method has been developed for this species. Little is known about its reproductive behavior under field conditions. We examined mating patterns of D. abbreviatus in a plant nursery in Florida by studying behavior of individually marked beetles. Matings occurred throughout the day but peaked during the middle of the day. Mating duration ranged from <3 h to >9 h. Males and females mated frequently, sometimes with the same partner multiple times. Intrasexual and extra-pair mountings occurred at low frequencies. We tested for direct benefits of multiple matings to females by examining the short-term effects of multiple matings on female fecundity and fertility and the effect of time since mating on female fertility. We found no short-term direct benefits of multiple mating but we found that female fertility decreased dramatically by 2 wks after mating if females are not allowed to remate. Thus, female D. abbreviatus may remate, in part, to replenish sperm stores.