Grasshopper (Orthoptera: Acrididae) Community Composition in the Rangeland of the Northern Slopes of the Qilian Mountains in Northwestern China T
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Journal of Insect Science RESEARCH Grasshopper (Orthoptera: Acrididae) Community Composition in the Rangeland of the Northern Slopes of the Qilian Mountains in Northwestern China T. Sun,1,2 Z. Y. Liu,2,3 L. P. Qin,2,3 and R. J. Long2,3,4 1Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China 2International Centre for Tibetan Plateau Ecosystem Management, Lanzhou University, Lanzhou 730020, China 3College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China 4Corresponding author, e-mail: [email protected] Subject Editor: Henry Hagedorn J. Insect Sci. 15(6): 2015; DOI: 10.1093/jisesa/ieu171 ABSTRACT. In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species simi- larity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the So¨rensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. Key Words: density, diversity, rangeland type, species composition Grasshoppers (Orthoptera: Acrididae) are among the most important caused severe damage to rangelands and influenced the local economy native herbivores in Northwestern China, causing large losses in of these regions. The control of grasshoppers and locusts has been a pasture areas. In an average year, more than 20 million ha of rangeland very important part of the rangeland management, and many useful suffer from grasshopper outbreaks in Northwest China, where grass- studies have been conducted to help individual herders and government hoppers annually consume an average of 1.6 billion kg of grass dry mat- agencies reduce the risk of outbreaks. Several studies have been under- ter, equivalent to an estimated loss of $80 million USD (Zhu 1999). taken of grasshopper community composition and species diversity in Considerable manpower and material resources have been expended on the Inner Mongolia Autonomous Region (Li and Kang 1991), Pampas the study of this problem. Previous studies of these insects have mostly of Argentina (Cigliano et al. 2000; Torrusio et al. 2002), Great Plains of focused on understanding the life-history strategies and diapause char- North America (Lockwood et al. 1994), and southern Africa acteristics (Lockwood et al. 1994, Hao and Kang 2004a,b, Zhao et al. (Gebeyehu and Samways 2006). Geographical ranges (Schluter and 2005), chemical and behavioral ecology (Chen and Kang 2000, Chen Ricklefs 1993, Zhang and Jiang 1997) and spatial heterogeneity et al. 2003), livestock grazing and grasshopper population dynamics (Davidowitz and Rosenzweig 1998, Pandolfi 2002) play an important (Kang et al. 1989, Kang and Chen 1995), and grasshopper community role in determining a community’s composition, diversity, and other at- structure (Li and Kang 1991, He et al. 1997). More recently, emphasis tributes of its organization. More spatially heterogeneous rangelands has been placed on the study of the complex ecological interactions provide a greater range of micro-habitats, which can attract greater between intraspecific and interspecific competition (Joern 1992, numbers of species able to co-exist within that ecosystem (Zhang and Belovsky 1997, Liu et al. 2007, Unsicker et al. 2010), climate conditions Jiang 1997, Davidowitz and Rosenzweig 1998). Thus, areas exhibiting (Kemp and Cigliano 1994, Belovsky and Slode 1995, Cigliano et al. greater floristic heterogeneity generally support more species of grass- 2002, Weiss et al. 2013), vegetation structure (Morris 2000, Sirin et al. hoppers than less heterogeneous areas (Otte 1976). However, few at- 2010, Hochkirch and Gro¨ning 2012), and their host plants (Branson and tempts have been made to analyze the relative abundance and species Sword 2007, Franzke et al. 2010, Bazelet and Samways 2011). composition of grasshopper communities in the rangeland of the north- The rangeland of the northern slopes of the Qilian Mountains is the ern slopes of the Qilian Mountains to help in developing management main stockbreeding base of Gansu Province in Northwestern China, strategies for controlling grasshopper numbers. The objective of this ar- which plays an important role in servicing the ecological environment ticle is to describe grasshopper species composition, richness, diversity, and socio-economics of the region (Wang et al. 2010). Various range- density, and abundance in different rangelands of this region and pro- land communities are used for raising yaks and sheep. However, grass- vide a rational basis for scientists, extension personnel, and rangeland hoppers, as the primary consumers and main component in rangeland managers when making decisions concerning research and manage- ecosystems, affect rangeland productivity and compete with domestic ment policies. Additional aims of the present study are to draw conclu- animals for food resources (Hewitt and Onsager 1983). At various sions regarding grasshopper communities of the Qilian Mountains and times in history, such as in the late 1980s and early 1990s, grasshoppers to offer an alternative method to control grasshopper in this area. VC The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected] 2 JOURNAL OF INSECT SCIENCE VOLUME 15 Table 1. Characteristics of the different RTs in the Qilian Mountains Characteristic Desert rangeland Mountain rangeland Alpine rangeland Alpine Altitude (m) 1,400–2,300 1,400–3,000 3,000–3,800 2,900–3,800 Mean annual precipitation (mm) 173–220 260–491 200–280 300–500 Yearly mean temperature (C) 3.6–6.0 0.2–2.1 À3.1 À5.4 to 0 Dominant grass species Kalidium foliatum, Stipa spp., Stipa purpurea, Cyperus spp., Artemisia spp. Artemisia spp. Elymus nutans Polygonum spp. Plant cover (%) 35–47 45–75 50–80 75–90 Height cm (cm) 20–35 20–30 15–20 10–15 Materials and Methods (Thunberg) (Acrididae), Chorthippus dubius (Zubovski), Chorthippus Study Area. The study area was located in the center of an area fallax (Zubovski), Gomphocerus licenti (Chang), Omocestus haemor- known as the Hexi (Gansu) Corridor and the northern slopes of the rhoidalis (Charpentier), Angaracris rhodopa (Fischer Walheim)) that Qilian Mountains, in the northwest of China. Longitude and latitude are were found in more than two RTs was compared among habitats and 37 280–39 490 N and 97 200–102 130 E, respectively, and the altitude years. ranges from 1,327 to 3,816 m. The climate is an extreme continental, Statistical analysis was conducted by ANOVA using SPSS with the desert, and plateau climate, with an annual average air temperature of GLM procedure (IBM, www.ibm.com). The model used for analyzing 4C. January is the coldest month, with temperatures reaching À24.9C data of the experiment included the factor (with RT and year as factors). and a daily average of À10.9C, while July is the warmest month, with Probability values at the P < 0.05 value were accepted as statistically an average daily temperature of 14.1C. Total annual precipitation and significant. evaporation averages 253 and 1,828 mm, respectively. The major soil type is the mountain chestnut soil, mountain chernozem soil. This Results region encompasses different available rangeland types (RTs) in the Species Composition and Taxonomic Diversity. In total, 4,350 country. In total, 20 sites were selected and classified into four catego- specimens of grasshoppers were collected during the 3 years, belonging ries (desert rangeland, mountain rangeland, alpine rangeland, and to 55 species, three families, and six subfamilies (Table 2). Average spe- alpine shrubland) according to the characteristics of vegetation and cies richness ranged from 10 to 23.7 species per category among the climate