title: Ecological Genetics and Host Range Expansion by Busseola fusca (Lepidoptera: Noctuidae).
abstract: The host plant range of pests can have important consequences for its evolution, and plays a critical role in the emergence and spread of a new pest outbreak. This study addresses the ecological genetics of the indigenous African maize stem borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae), in an attempt to investigate the evolutionary forces that may be involved in the recent host range expansion and establishment of this species in Ethiopian and southern African sugarcane. We used populations from Ethiopia, Zimbabwe, and South Africa to examine whether the host range expansion patterns shared by the Ethiopian and the southern African populations of B. fusca have evolved independently. Base-pair differences in the cytochrome oxidase I (COI) gene were used to characterize haplotype diversity and phylogenetic relationships. There were seven haplotypes among the 30 sequenced individuals collected on four host plant species from 17 localities in the four countries. Of the seven COI haplotypes identified, the two major ones occurred in both sugarcane and maize. Genetic analyses revealed no detectable genetic differentiation between southern African B. fusca populations from maize and sugarcane (FST = 0.019; P = 0.24). However, there was strong evidence of variation in genetic composition between populations of the pest from different geographic regions (FST = 0.948; P < 0.001). The main implication of these findings is that the B. fusca populations in maize in southern Africa are more likely to shift to sugarcane, suggesting that ecological opportunity is an important factor in host plant range expansion by a pest.
authors: Department of Zoology and Entomology, University of Fort Hare, Faculty of Science and Agriculture, Private Bag X1314, Alice 5700, South Africa. yarmide@ufh.ac.za.
authors: Y
authors: Y
authors: Assefa
authors: South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe, 4300, South Africa. School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg, Scottsville 3209, South Africa.
authors: D E
authors: DE
authors: Conlong
authors: Unit of Environmental Sciences and Development, North-West University, Potchefstroom 2520, South Africa.
authors: J
authors: J
authors: Van Den Berg
authors: South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe, 4300, South Africa.
authors: L A
authors: LA
authors: Martin
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D005002:Ethiopia; D014644:Genetic Variation; D006239:Haplotypes; D060434:Herbivory; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013019:South Africa; D013045:Species Specificity; D015030:Zimbabwe
chemical_list: D019476:Insect Proteins; D003576:Electron Transport Complex IV
keywords: Busseola fusca; ecological genetics; host range expansion; sugarcane