Population monitoring and morphometrics of Helicoverpa armigera (Hübner), Helicoverpa zea (Boddie), and their hybrids (Lepidoptera: Noctuidae) in Puerto Rico

dc.contributor.advisor Verle-Rodrigues, José C. Trujillo, Darío X. College of Agricultural Sciences en_US
dc.contributor.committee Ferwerda, Feiko
dc.contributor.committee Gallardo, Fernando
dc.contributor.department Department of Crops and Agro-Environmental Sciences en_US
dc.contributor.representative Acosta, Jaime 2018-09-11T18:01:12Z 2018-09-11T18:01:12Z 2018-07-20
dc.description.abstract Helicoverpa armigera and H. zea are serious pests in many crops; H. armigera was detected in 2014 in Puerto Rico. In the period February 2016 to January 2017, 112 traps with a lure for H. armigera were installed in Guanica, Santa Isabel, Guayama, Isabela, Lajas, Juana Diaz, Añasco, Aguadilla, Sabana Grande, Mayagüez, San Juan, Gurabo, Villalba, and Jayuya. The two lepidopterans were identified with morphology. Insects identified as H. armigera with morphology were corroborated with molecular tools. Comparisons of Helicoverpa populations between localities and among crops in each locality were done with non-parametric tests. Data of moth capture by a bell pepper farm in Santa Isabel was used to analyze relationship with weather variables. A total of 5,122 Helicoverpa specimens were captured, four were identified as H. armigera, and the remaining were H. zea. In San Juan, Gurabo, Villalba, and Jayuya any Helicoverpa was captured. The highest H. zea populations were in the period February to May. Santa Isabel had the highest H. zea populations. In the comparisons among crops, only okra in Guanica had higher H. zea populations over sunflower. In Santa Isabel, populations of H. zea had a significantly negative relationship with maximum temperature, and precipitation depending on the period analyzed. F1 hybrids between H. armigera and H. zea were obtained at the Center for Excellence in Quarantine and Invasive Species. For morphological comparison, the following variables were analyzed: number of lobes, number of cornuti, length of valves, length of aedeagus, and depth in the posterior excavation in the eighth sternite. The species H. armigera is characterized by the presence of one lobe while F1 hybrids and H. zea showed three lobes. Statistical analysis with the other quantitative variables showed that H. zea had the biggest structures or more cornuti, followed by the hybrids, and finally H. armigera with the smallest size of structures and a minor number of cornuti. The principal components analysis of quantitative variables showed that F1 hybrids were closer to H. zea. Currently, we can infer that using only morphology is very difficult to identify one Helicoverpa as a hybrid or distinguish a true hybrid from a parental species. en_US
dc.description.graduationSemester Summer en_US
dc.description.graduationYear 2018 en_US
dc.description.sponsorship I want to thank the Department of Agriculture of United States (USDA), Animal and Plant Health Inspection Service (APHIS), National Institute of Food and Agriculture (NIFA), projects USDA-APHIS AP17PPQS&T00C189, USDA-APHIS 8130-0613-CA, and USDA-NIFA AGFEI 2017-70004-27294 for the support for this research. en_US
dc.language.iso en en_US
dc.rights.holder (c) 2018 Darío Trujillo en_US
dc.rights.license All rights reserved en_US
dc.subject Old World Bollworm en_US
dc.subject Invasive Species en_US
dc.subject.lcsh Helicoverpa --Identification en_US
dc.subject.lcsh Helicoverpa -- Monitoring en_US
dc.subject.lcsh Helicoverpa armigera --Puerto Rico --Morphology en_US
dc.subject.lcsh Heliothis Zea -- Morphology en_US
dc.subject.lcsh Bell pepper -- Diseases and pests -- Control -- Puerto Rico en_US
dc.subject.lcsh Lepidoptera -- Puerto Rico en_US
dc.subject.lcsh Regression analysis en_US
dc.title Population monitoring and morphometrics of Helicoverpa armigera (Hübner), Helicoverpa zea (Boddie), and their hybrids (Lepidoptera: Noctuidae) in Puerto Rico en_US
dc.type Thesis en_US
dspace.entity.type Publication Crop Protection en_US M.S. en_US
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