|BARR, NORMAN - Animal And Plant Health Inspection Service (APHIS)|
|LEDEZMA, LISA - Animal And Plant Health Inspection Service (APHIS)|
|LEBLANC, LUC - University Of Hawaii|
|SAN JOSE, MICHAEL - University Of Hawaii|
|RUBINOFF, DANIEL - University Of Hawaii|
|FUJITA, BRIAN - Animal And Plant Health Inspection Service (APHIS)|
|BARTELS, DAVID - Animal And Plant Health Inspection Service (APHIS)|
|GARZA, DANIEL - Animal And Plant Health Inspection Service (APHIS)|
|KERR, PETER - California Department Of Agriculture|
|HAUSER, MARTIN - California Department Of Food And Agriculture|
|GAIMARI, STEPHAN - California Department Of Food And Agriculture|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2014
Publication Date: 10/20/2014
Citation: Barr, N.B., Ledezma, L.A., Leblanc, L., San Jose, M., Rubinoff, D., Geib, S.M., Fujita, B., Bartels, D., Garza, D., Kerr, P., Hauser, M., Gaimari, S. 2014. Genetic diversity of Bactrocera dorsalis (Diptera: Tephritidae) on the Hawaiian Islands: Implications for an introduction pathway into California. Journal of Economic Entomology. 107(5):1946-1958.
Interpretive Summary: Samples of oriental fruit fly (Bactrocera dorsalis) were collected from throughout the Hawaiian Islands (the four main islands) and the population structure of these flies was determined using a mitochondrial marker. This shows that there is very little genetic diversity in the Hawaiian Islands and that diversity is centered on two very closely related genetic types. In addition, these Hawaiian samples were compared to 165 oriental fruit flies that were trapped in California from 2006-2012 by examining the same mitochondrial region. If the genetic type in a particular fly is different than the genetic types sampled in Hawaii, then the assumption can be made that the California fly did not originate directly from a Hawaiian population. If the fly has the same genetic type as a Hawaiian fly, than the possibility that the fly originated from a Hawaiian population cannot be excluded. Examining the 165 flies, 69 of them had a genetic type similar or the same to a Hawaiian sample, while the rest had a distinct genetic type relative to the Hawaiian samples, suggesting a non-Hawaiian origin. Because of the high number of genetic types in California over time and space, this suggest California experienced multiple, independent introductions of oriental fruit fly from different sources.
Technical Abstract: Population genetic diversity of the oriental fruit fly, Bactrocera dorsalis, on the Hawaiian islands of Oahu, Maui, Kauai, and Hawaii (the Big Island) was estimated using DNA sequences of the mitochondrial cytochrome c oxidase subunit I gene. A total of 932 flies representing 36 sampled sites across the four islands were sequenced for a 1500 bp fragment of the gene named the C1500 marker. Genetic variation was low on the Hawaiian Islands with over 96% of flies having just two haplotypes: C1500-Haplotype 1 (63.2%) or C1500-Haplotype 2 (33.3%). The other 33 flies (3.5%) had haplotypes similar to the two dominant haplotypes. No population structure was detected among the islands or within islands. The two haplotypes were present at similar frequencies at each sample site suggesting that flies on the various islands can be considered one population. Comparison of the Hawaiian data set to DNA sequences of 165 flies from outbreaks in California between 2006 and 2012 indicates that a single-source introduction pathway of Hawaiian origin cannot explain many of the flies in California. Hawaii, however, could not be excluded as a maternal source for 69 flies. There was no clear geographic association for Hawaiian or non-Hawaiian haplotypes in the Bay Area or LA Basin over time. This suggests that California experienced multiple, independent introductions from different sources.