Influence of plant direction, layer and spacing on the infestation levels of Anthonomus eugenii (Coleoptera: Curculionidae) in open jalapeño pepper fields in north Florida

Authors: WU, PENGXIANG - Institute Of Zoology - China; HASEEB, MUHAMMAD - Florida A & M University; DIEDRICK, WORREL - Florida A & M University; OUYANG, HAOYONG - Institute Of Zoology - China; ZHANG, RUNZHI - Institute Of Zoology - China; KANGA, LAMBERT - Florida A & M University; Legaspi, Jesusa

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2019
Publication Date: 9/30/2019
Citation: Wu, P., Haseeb, M., Diedrick, W., Ouyang, H., Zhang, R., Kanga, L.H., Legaspi, J.C. 2019. Influence of plant direction, layer and spacing on the infestation levels of Anthonomus eugenii (Coleoptera: Curculionidae) in open jalapeño pepper fields in north Florida. Florida Entomologist. 102(3):501-508. https://doi.org/10.1653/024.102.0319.
DOI: https://doi.org/10.1653/024.102.0319

Interpretive Summary: Pepper weevil is a major insect pest of peppers in north Florida. To minimize crop damage by this pest, proper monitoring of the fruit infestation and population numbers of weevils is important as part of an effective control strategy. Scientists at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Tallahassee, FL, in collaboration with researchers from Florida A&M University evaluated the infestation levels and numbers of pepper weevils in different layers, directions and spacing of plants throughout the season to determine the best time to apply control measures. During a growing season, pepper weevil numbers begin increasing when plants start to produce buds and flowers. Three major peaks of fruit infestation occurred during the summer with the maximum occurring in mid-summer. Fruits on the eastern part and top third of the pepper plants as well as those planted about 40 cm apart had the lowest fruit infestation. Fruits in the central portion and bottom of the plants had the highest pepper weevil numbers. These studies indicate that targeted control measures such as insecticide applications to specific parts of plants may be more efficacious delivering better management of the pepper weevil.

Technical Abstract: Pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a most serious pest of peppers in north Florida. To analyze A. eugenii infestation levels on Jalapeño peppers as a reference for effectively controlling pepper weevil, the infestation and population dynamics of A. eugenii, and influence of plant direction, layer, and spacing were studied in open fields in north Florida. The results showed that adult pepper weevil infestation started in late Apr when plants started to produce buds and flowers. Three infestation peaks were recorded on 9 Jun, 24 Jul, and 11 Sep. The second peak showed highest infestation level (14.6 ± 2.7 infested fruits per plant). The density curve of A. eugenii larvae within fruits lagged about 2-4 wks behind the curve of infestation level in the field. Three peaks occurred on 10 Jul, 21 Aug, and 25 Sep. Fruits on the eastern part and top third of pepper plants had lowest infestation levels, as did plants spaced at 40 cm distance apart. This study, focusing on the preferred locations of A. eugenii, will help improve sampling technique and pest management applications, and thus enhance the effectiveness of pesticide application and ultimately reduce ecological damage.