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文獻來源: Elkinton et al. 2009. Survey for Winter Moth (Lepidoptera: Geometridae) in Northeastern North America With Pheromone-Baited Traps and Hybridization With the Native Bruce Spanworm (Lepidoptera: Geometridae). Ann. Entomol. Soc. Am. 103(2): 135. [link]
簡 介
本文以費洛蒙陷阱調查北美地區之歐洲外來冬尺蛾winter moth (Operophtera brumata)與原生種 Bruce spanworm (O. bruceata)之野外族群分布範圍，並依據粒腺體DNA COI序列與雄性外生殖器鉤狀突(uncus)進行兩物種鑑定，以及測量鉤狀突所得到的中間型個體來推測兩物種間存在雜交的可能，再以核DNA G6PD基因序列來驗證此假設(COI序列為母系遺傳，僅能作物種鑑定無法檢驗雜交)。所得到的結果顯示北美此兩物種的(1) COI序列差異達7.45%; (2) 由G6PD序列確認的確有自然雜交個體存在，然而比例上並沒有過去認知的高，於158個取樣僅出現3個體 (1.9%); (3) 鉤狀突測量呈現一個相當大的變異範圍，且中間型的個體在COI序列鑑定為O. brumata，顯示鉤狀突並不是 一個可精確區分兩物種的特徵。
ABSTRACT
We used pheromone-baited traps to survey the distribution of winter moth, Operophtera brumata (L.) (Lepidoptera: Geometridae), a new invasive defoliator from Europe in eastern New England. The traps also attracted Bruce spanworm, Operophtera bruceata (Hulst) (Lepidoptera: Geometridae), native to North America.We distinguished between the two species by examining male genitalia and sequencing the mitochondrial cytochrome oxidase subunit 1 (COI) gene, the DNA barcoding region. In 2005, we recovered winter moths at sites stretching from eastern Long Island, southeastern Connecticut, all of Rhode Island, eastern Massachusetts, coastal New Hampshire, and southern coastal Maine. At sites further west and north we captured only Bruce spanworm. In 2006, we conformed that both winter moth and Bruce spanworm are present in Nova Scotia and in coastal Maine, but only Bruce spanworm was recovered in coastal New Brunswick, Canada; Pennsylvania; Vermont; or Quebec City, Canada. In 2007, we collected Bruce spanworm, but no winter moths, in New Brunswick and the interior areas of Maine, New Hampshire, and New York. Winter moth and Bruce spanworm differed in the COI sequence by 7.45% of their nucleotides. The prevalence of intermediate genitalia in the zone of overlap suggested that hybridization between the two species may be occurring. To confirm the presence of hybrids, we sequenced the nuclear gene, glucose-6-phosphate dehydrogenase (G6PD). We identified six nucleotides that routinely distinguished winter moth and Bruce spanworm, of which three were always diagnostic. We showed that eggs produced by hybridizing the two species in the laboratory contained copies of both species at these six sites. We found that most of the moths collected in the field with intermediate genitalia had winter moth CO1 and G6PD sequences and thus were not hybrids (or at least F1 hybrids). We found three hybrids out of 158 moths with intermediate genitalia in the region where both species were caught. We conclude that hybrids occur in nature, but are not as common as previously reported. Introgression of genes between the two species may still be significant.
簡 介
本文以費洛蒙陷阱調查北美地區之歐洲外來冬尺蛾winter moth (Operophtera brumata)與原生種 Bruce spanworm (O. bruceata)之野外族群分布範圍，並依據粒腺體DNA COI序列與雄性外生殖器鉤狀突(uncus)進行兩物種鑑定，以及測量鉤狀突所得到的中間型個體來推測兩物種間存在雜交的可能，再以核DNA G6PD基因序列來驗證此假設(COI序列為母系遺傳，僅能作物種鑑定無法檢驗雜交)。所得到的結果顯示北美此兩物種的(1) COI序列差異達7.45%; (2) 由G6PD序列確認的確有自然雜交個體存在，然而比例上並沒有過去認知的高，於158個取樣僅出現3個體 (1.9%); (3) 鉤狀突測量呈現一個相當大的變異範圍，且中間型的個體在COI序列鑑定為O. brumata，顯示鉤狀突並不是 一個可精確區分兩物種的特徵。
ABSTRACT
We used pheromone-baited traps to survey the distribution of winter moth, Operophtera brumata (L.) (Lepidoptera: Geometridae), a new invasive defoliator from Europe in eastern New England. The traps also attracted Bruce spanworm, Operophtera bruceata (Hulst) (Lepidoptera: Geometridae), native to North America.We distinguished between the two species by examining male genitalia and sequencing the mitochondrial cytochrome oxidase subunit 1 (COI) gene, the DNA barcoding region. In 2005, we recovered winter moths at sites stretching from eastern Long Island, southeastern Connecticut, all of Rhode Island, eastern Massachusetts, coastal New Hampshire, and southern coastal Maine. At sites further west and north we captured only Bruce spanworm. In 2006, we conformed that both winter moth and Bruce spanworm are present in Nova Scotia and in coastal Maine, but only Bruce spanworm was recovered in coastal New Brunswick, Canada; Pennsylvania; Vermont; or Quebec City, Canada. In 2007, we collected Bruce spanworm, but no winter moths, in New Brunswick and the interior areas of Maine, New Hampshire, and New York. Winter moth and Bruce spanworm differed in the COI sequence by 7.45% of their nucleotides. The prevalence of intermediate genitalia in the zone of overlap suggested that hybridization between the two species may be occurring. To confirm the presence of hybrids, we sequenced the nuclear gene, glucose-6-phosphate dehydrogenase (G6PD). We identified six nucleotides that routinely distinguished winter moth and Bruce spanworm, of which three were always diagnostic. We showed that eggs produced by hybridizing the two species in the laboratory contained copies of both species at these six sites. We found that most of the moths collected in the field with intermediate genitalia had winter moth CO1 and G6PD sequences and thus were not hybrids (or at least F1 hybrids). We found three hybrids out of 158 moths with intermediate genitalia in the region where both species were caught. We conclude that hybrids occur in nature, but are not as common as previously reported. Introgression of genes between the two species may still be significant.
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