Tsen Hua
Department of Entomology, National Chung Hsing University, Taichung 402, Taiwan
Department of Plant Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
Hui-Yi Li
Department of Entomology, National Chung Hsing University, Taichung 402, Taiwan.
Cheng-Lung Tsai
Department of Entomology, National Chung Hsing University, Taichung 402, Taiwan
Department of Biology, National Museum of Natural Science, Taichung 404, Taiwan.
Wing Wei Wang
Taiwan Forestry Research Institute, Taipei 100, Taiwan.
Chao-Yuan Lin
Department of Soil and Water Conservation, National Chung Hsing University, Taichung 402, Taiwan.
Wen-Bin Yeh
Department of Entomology, National Chung Hsing University, Taichung 402, Taiwan.
Communicated by Shen-Horn Yen
Plant communities that colonize high-elevation zones generally have short growing seasons, which leads to specialized adaptations in such zones. In montane areas of Taiwan, Yushan bamboo (YB, Yushania niitakayamensis) is dominant at elevations ranging from 2500 to 3300 m and grows in a grassland-like open habitat. In this study, hexapods were collected from YB bimonthly between 2009 and 2012 by using a sweeping net. The composition of and several bioindices for the hexapods were determined, and multivariate analyses were conducted to explore the dynamics and seasonal distribution of the hexapods. A total of 32,000 individuals belonging to 11 orders and 113 families were collected, with adult individuals being collected more frequently in warmer seasons (from June to October). Of the sampled individuals, 90% belonged to the orders Collembola (42%), Hemiptera (35%), and Hymenoptera (13%). The number of individuals belonging to Hemiptera were stable in all seasons, and the number of hymenopteran wasps was influenced by temperature and exhibited a stable dynamic pattern. The number of individuals belonging to Collembola fluctuated drastically. The multivariate analyses revealed that the collected hexapods could be divided into two major family groups according to survey season (i.e., summer and winter groups). Several families were collected only in summer, but a few were collected only in winter. Eigenvalues obtained from a principal component analysis revealed that the families Chironomidae, Delphacidae, Entomobryidae, Hypogastruridae, Sminthuridae, and Thripidae (all dominant) were the major contributors to the winter group. These families were abundant all year, although some were more abundant during winter. The three dominant orders Collembola, Hemiptera, and Hymenoptera, each of which has a distinct community structure and dynamic pattern, may have their own adaptive mechanisms in the subtropical regions of Taiwan. Hemiptera individuals, which feed on YB, were most abundant in the adult stage in summer and in the nymphal stage in winter. The abundance of parasitic hymenopteran wasps, which had stable dynamic patterns, was associated with that of their host insects and temperature. The drastic fluctuations in the abundance of Collembola may have been caused by abiotic factors, such as precipitation and microhabitat factors. The early onset of spring and the late onset of winter might also affect the dynamics of the studied hexapods.
Supplementary materials
Individuals belonging to the dominant families Cicadellidae (diamond), Entomobryidae (triangle), and Sminthuridae (circle) as identified in the bimonthly surveys during 2009–2012.
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Spatial distribution of the insect families identified in all surveys during 2009–2012, as determined through nonmetric multidimensional scaling analysis. The similarities between the group patterns and statistical results are displayed.
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Hierarchical clustering analysis based on the unweighted pair-group average method for hexapod families identified in all bimonthly surveys during 2009–2012. The summer group, winter group, and the similarities between clusters are displayed.
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Relative abundance of the dominant hexapod families—as determined through principal component analysis—identified in surveys during 2009–2012. The size of the circle below each panel is proportional to the number of individuals collected. (A) Cicadellidae, (B) Entomobryidae, (C) Sminthuridae, (D) Chironomidae, and (E) Delphacidae.
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Numbers of individuals in the Hymenoptera (triangle), Insecta (square), and Hemiptera (gray circle) families identified during 2009–2012. Temperature is presented in empty circles. The Pearson correlation coefficients (
r) of Hymenoptera, Insecta, and Hemiptera with Temperature are displayed.
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Daily temperature, humidity, and precipitation in the survey area on Mt. Shei. The red shading indicates the bimonthly survey day.
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List of all 11 orders along with the numbers of individuals belonging to each of the 113 families.
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Pertinent information for the hexapod collection in the survey area on Shei Moutain in 2009- 2012.
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Eigenvalues derived from the principal component analysis of the morphospecies of each hexapod family.
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