Jacobi W R, Koski R D, Harrington T C, Witcosky J J
Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins 80523.
Department of Plant Pathology, Iowa State University, Ames 50011.
Plant Dis. 2007 Mar;91(3):245-247. doi: 10.1094/PDIS-91-3-0245.
The smaller European elm bark beetle, Scolytus multistriatus, has been the primary vector of the Dutch elm disease fungus, Ophiostoma novo-ulmi, in elm trees in Colorado since 1948. An exotic from Asia, the banded elm bark beetle, Scolytus schevyrewi, was found in Siberian elm, Ulmus pumila, in Colorado in April of 2003; this was the first report of S. schevyrewi in North America. S. schevyrewi is now found throughout much of Colorado and in at least 21 other states. The similarities in breeding and feeding habits between S. schevyrewi and S. multistriatus have raised concerns about the ability of S. schevyrewi to serve as a vector for O. novo-ulmi. The objective of this preliminary study was to determine if O. novo-ulmi could be isolated from adult S. schevyrewi emerging from diseased elm trees. S. schevyrewi and S. multistriatus were allowed to infest diseased stem segments of American elm, Ulmus americana. The infested stem segments were caged and isolations were made from the adult brood that emerged. O. novo-ulmi was isolated from most of the adults of both beetle species, showing that S. schevyrewi could acquire the pathogen as effectively as S. multistriatus. Future studies are needed to determine if S. schevyrewi can effectively transmit the pathogen to healthy trees.
自1948年以来，体型较小的欧洲榆小蠹（Scolytus multistriatus）一直是荷兰榆树病真菌新榆枯萎病菌（Ophiostoma novo-ulmi）在科罗拉多州榆树中的主要传播媒介。带状榆小蠹（Scolytus schevyrewi）是一种来自亚洲的外来物种，2003年4月在科罗拉多州的西伯利亚榆（Ulmus pumila）中被发现；这是北美首次报道发现带状榆小蠹。目前在科罗拉多州的大部分地区以及至少其他21个州都发现了带状榆小蠹。带状榆小蠹和欧洲榆小蠹在繁殖和取食习性上的相似性引发了人们对带状榆小蠹作为新榆枯萎病菌传播媒介能力的担忧。这项初步研究的目的是确定是否能从患病榆树中羽化出的成年带状榆小蠹体内分离出新榆枯萎病菌。让带状榆小蠹和欧洲榆小蠹侵染美国榆（Ulmus americana）的患病茎段。将被侵染的茎段装入笼中，并从羽化出的成虫后代中进行分离。在这两种甲虫的大多数成虫体内都分离到了新榆枯萎病菌，这表明带状榆小蠹获取病原体的能力与欧洲榆小蠹相当。未来需要开展研究来确定带状榆小蠹是否能有效地将病原体传播给健康树木。
