Decreasing Species Richness with Increase in Elevation and Positive Rapoport Effects of Crambidae (Lepidoptera) on Mount Taibai

Abstract

Rapoport’s rule proposes that a species’ range size increases with the increase in a gradient (such as latitude, altitude or water depth). However, altitudinal distributions and Rapoport’s rule have rarely been tested for Asian Lepidoptera. Pyraustinae and Spilomelinae (Lepidoptera: Crambidae) are extremely diverse in temperate Asia, including on Mount Taibai, which is considered a hotspot area for studying the vertical distribution patterns of insect species. Based on the investigation of altitudinal distribution data with identification by using both DNA barcoding and the morphological classification of Pyraustinae and Spilomelinae, this paper determines the altitudinal gradient pattern for these two subfamilies on the north slope of Mount Taibai, and provides a test of the universality of Rapoport’s rule in Lepidoptera by using four methods, including Stevens’ method, Pagel’s method, Rohde’s method, and the cross-species method. Our results show that the alpha diversity of Pyraustinae and Spilomelinae both decrease with rising altitude. By contrast, the species’ ranges increase with rising altitude. Three of the four methods used to test Rapoport’s rule yielded positive results, while Rohde’s results show a unimodal distribution model and do not support Rapoport’s rule. Our findings fill the research gap on the elevational diversity of Lepidoptera in temperate Asia.

Rapoport's rule explains the range size distribution of butterflies along the Eastern Himalayan elevation gradient

“…It is generally accepted that species range size often follows a log‐normal distribution with left skew across various taxa and regions due to the presence of a considerably greater number of small‐ranged species (Gaston, 1996; Gaston & Blackburn, 1996; Takashina et al., 2022). In the Rangeet valley, elevational range size distribution showed a perceived pattern of a left‐skewed distribution as most of the species displayed narrow elevational ranges consistent with other studies in butterflies (Acharya & Vijayan, 2015; Fleishman et al., 1998; Pyrcz et al., 2009) and moths (Chen et al., 2022). A greater number of narrow‐range species are especially observed in tropical environments, where most species are limited by physiological mechanisms that permit them to survive only in those environments close to their optimal thermal ranges (Deutsch et al., 2008).…”

“…On the other hand, species with mid‐points at the middle of the domain can show range extension towards both directions (Blackburn & Gaston, 1996; Colwell, & Hurtt., G. C., 1994). A similar pattern has been observed in moths (Chen et al., 2022), mammals (Luo et al., 2011) and plants (Li et al., 2022) where these methods were used in a complementary way to test Rapoport's rule. Differences in patterns influenced by the methodologies in our study suggest that the perceived pattern of spatial distribution can be greatly affected by the approaches used for the analysis.…”

“…These methods help in correcting biases and account for data non‐independency (Letcher & Harvey, 1994). Moreover, the fact that Rapoport's rule may not apply to a particular group (s) does not diminish its validity as an explanatory principle for understanding range size distribution in other organisms such as plants (Feng et al., 2016; Liang et al., 2021) and insects (Chen et al., 2022; Fleishman et al., 1998; Sanders, 2002) which have been found to support the rule. The insights on range size helps in understanding patterns of species diversity, abundance, and community composition (Jetz & Rahbek, 2002; Morin & Chuine, 2006).…”

Biodiversity and Spatiotemporal Variations of Mecoptera in Thailand: Influences of Elevation and Climatic Factors

“…The spatial distribution of insects has been reported in various insect groups, and the results revealed different relationships depending on the taxa [ 23 , 29 , 30 , 64 , 65 , 66 , 67 ]. Our result showed a hump-shaped distribution pattern of this insect, which was similar to previous reports from the Qinling mountains in Yunan province and the Sichuan Basin in Sichuan province, China, suggesting that the highest species numbers occurred in the middle elevation [ 22 , 68 ].…”

Vegetation Affects the Responses of Canopy Spider Communities to Elevation Gradients on Changbai Mountain, China

“…Mountain ranges are known to harbor exceptionally high biodiversity [ 1 , 2 ] and, thus, they provide an ideal condition for studying the variation in community structure along elevational gradients [ 3 ]. Many studies have focused on the effects of elevation on plants [ 4 ], mammals [ 5 ], anurans [ 6 ], birds [ 7 ], and arthropods [ 8 , 9 , 10 ]. Furthermore, some authors have studied the influence of multiple groups from different trophic levels [ 11 , 12 ].…”