P. Susai Nathan

Island ecosystems have significant conservation value owing to their higher endemic biotas. Moreover, studies of regional communities that compare differences in species composition (species dissimilarity) among islands and the mainland suggest that community assembly on islands is different from that on the mainland. However, the uniqueness of island biotic assembly has been little studied at the global scale, nor have phylogenetic information or alien species been considered in these patterns. We evaluate taxonomic and phylogenetic change from one community to the next, focusing on differences in species composition between mainland-mainland (M-M) pairs compared to differences between mainland-island pairs (M-I) and between island-island pairs (I-I), using herpetofauna on islands and adjacent mainland areas worldwide. Our analyses detect greater taxonomic and phylogenetic dissimilarity for M-I and I-I comparisons than predicted by M-M model, indicating different island herpetofauna assembly patterns compared with mainland counterparts across the world. However, this higher M-I dissimilarity has been significantly decreased after considering alien species. Our results provide global evidence on the importance of island biodiversity conservation from the aspect of both the taxonomic and phylogenetic uniqueness of island biotic assembly.

Predicting global change effects poses significant challenges due to the intricate interplay between climate change and anthropogenic stressors in shaping ecological communities and their function, such as pest outbreak risk. Termites are ecosystem engineers, yet some pest species are causing worldwide economic losses. While habitat fragmentation seems to drive pest-dominated termite communities, its interaction with climate change effect remains unknown. We test whether climate and habitat fragmentation interactively alter interspecific competition that may limit pest termite risk. Leveraging global termite co-occurrence including 280 pest species, we found that competitively superior termite species (e.g., large bodied) increased in large and continuous habitats solely at high precipitation. While competitive species suppressed pest species globally, habitat fragmentation drove pest termite risk only in humid biomes. Unfortunately, hu- mid tropics have experienced vast forest fragmentation and rainfall reduction over the past decades. These stressors, if not stopped, may drive pest termite risk, potentially via competitive release.

Sarcophagid experts have made several efforts to associate biodiversity data and comprehend where each species occurs, but comprehensive faunal inventories remain scarce. Our aim was to provide a list of distributional patterns and endemic species and allow assessment of the sampling effort conducted within Brazilian biomes. We produced a dataset of Brazilian sarcophagids and overlaid with a biome map, to investigate distributional patterns, endemism and to build species accumulation curves. Additionally, we calculated nonparametric asymptotic species richness estimators and extrapolation of species diversity (Hill numbers). Our dataset comprised 288 sarcophagid species, which 21 were identified as endemic. The biomes with the highest species richness were the Atlantic Rainforest and the Amazon Forest, and no biome exhibited a stabilized asymptotic curve. This is the first proposal of listing Sarcophagidae species by biomes and essential to understand the spatial distribution of this family in Brazil. We present maps and richness estimators that allow identifying gaps and guiding survey planning.

Biological invasions are among the threats to global biodiversity and social sustainability, especially on islands. Identifying the threshold of area at which non-native species begin to increase abruptly is crucial for early prevention strategies. The small-island effect (SIE) was proposed to quantify the nonlinear relationship between native species richness and area but has not yet been applied to non-native species and thus to predict the key breakpoints at which established non-native species start to increase rapidly. Based on an extensive global dataset, including 769 species of non-native birds, mammals, amphibians and reptiles established on 4277 islands across 54 archipelagos, we detected a high prevalence of SIEs across 66.7% of archipelagos. Approximately 50% of islands have reached the threshold area and thus may be undergoing a rapid increase in biological invasions. SIEs were more likely to occur in those archipelagos with more non-native species introduction events, more established historical non-native species, lower habitat diversity and larger archipelago area range. Our findings may have important implications not only for targeted surveillance of biological invasions on global islands but also for predicting the responses of both non-native and native species to ongoing habitat fragmentation under sustained land-use modification and climate change.

Global warming has seriously disturbed the Earth’s ecosystems, and in this context, Asian honeybee (Apis cerana) has experienced a dramatic decline in recent decades. Here, we examined both direct and indirect effects of climate change on A. cerana through ecological niche modeling of A. cerana, and its disease pathogens (i.e., Chinese sacbrood virus and Melissococcus plutonius) and enemies (i.e., Galleria mellonella and Vespa mandarinia). Ecological niche modeling predicts that climate change will increase the potential suitability of A. cerana, but it will also cause some of the original habitat areas to become unsuitable. Outbreak risks of Chinese sacbrood disease and European Foulbrood will increase dramatically, while those of G. mellonella and V. mandarinia will decrease only slightly. Thus, climate change will produce an unfavorable situation for even maintaining some A. cerana populations in China in the future. Genetic structure analyses showed that the A. cerana population from Hainan Island had significant genetic differentiation from that of the mainland, and there was almost no gene flow between the 2, suggesting that urgent measures are needed to protect the unique genetic resources there. Through taking an integrated planning technique with the Marxan approach, we optimized conservation planning, and identified potential nature reserves (mainly in western Sichuan and southern Tibet) for conservation of A. cerana populations. Our results can provide insights into the potential impact of climate change on A. cerana, and will help to promote the conservation of the keystone honeybee in China and the long-term sustainability of its ecosystem services.

Ceratitis capitata (Wiedemann), the Mediterranean fruit fly or medfly, is one of the world's most serious threats to fresh fruits. It is highly polyphagous (recorded from over 300 hosts) and capable of adapting to a wide range of climates. This pest has spread to the EPPO region and is mainly present in the southern part, damaging Citrus and Prunus. In Northern and Central Europe records refer to interceptions or short‐lived adventive populations only. Sustainable programs for surveillance, spread assessment using models and control strategies for pests such as C. capitata represent a major plant health challenge for all countries in Europe. This article includes a review of pest distribution and monitoring techniques in 11 countries of the EPPO region. This work compiles information that was crucial for a better understanding of pest occurrence and contributes to identifying areas susceptible to potential invasion and establishment. The key outputs and results obtained in the Euphresco project included knowledge transfer about early detection tools and methods used in different countries for pest monitoring. A MaxEnt software model resulted in risk maps for C. capitata in different climatic regions. This is an important tool to help decision making and to develop actions against this pest in the different partner countries.

Migration studies include spectacular examples from vertebrates, such as birds, bats, and turtles. However, insect migration studies have lagged due to a restrictive definition of what entails migration and because of constraints in tracking insect movement. This has changed in recent times with studies on migratory butterflies, moths, and dragonflies. However, studies on collective migration by social insects such as honey bees are still largely lacking, despite their impact on ecosystem services, food security, and biodiversity. In this review, we synthesise findings from scattered studies on migration in a subset of honey bee species to better understand this phenomenon and to provide impetus for future research. As a general trend, migration in the genus Apis begins with a shift from a statary to a migratory phase within colonies, characterised by greater scout activity and consensus-building with respect to the direction of departure using migratory waggle dances. Once air-borne, the finer details of a swarm’s movement are unknown for any Apis species. Swarms reportedly make multiple stops, and while temporarily existing as comb-less clusters at these sites, the decision-making process occurs repeatedly, until nest-selection dances occur and the migratory phase finally culminates. We highlight the need for studies into the drivers and mechanisms of honey bee migration, as well as the promise of initiatives such as citizen science and tools such as pollen metabarcoding in studying migration in honey bees. This is particularly needed, given that rapidly changing habitats and climate could affect honey bee migration and the pollination services they provide.

Our understanding of broad-scale biodiversity and functional trait patterns is largely based on plants, and relatively little information is available on soil arthropods. Here, we investigated the distribution of termite diversity globally and morphological traits and diversity across China. Our analyses showed increasing termite species richness with decreasing latitude at both the globally, and within-China. Additionally, we detected obvious latitudinal trends in the mean community value of termite morphological traits on average, with body size and leg length decreasing with increasing latitude. Furthermore, temperature, NDVI and water variables were the most important drivers controlling the variation in termite richness, and temperature and soil properties were key drivers of the geographic distribution of termite morphological traits. Our global termite richness map is one of the first high resolution maps for any arthropod group and especially given the functional importance of termites, our work provides a useful baseline for further ecological analysis.

Pollinators play an important role in ecosystems, but global climate change threatens the diversity and geographical distribution of pollinators. Bees are some of the most important pollinators and are particularly sensitive to climate change and environmental change. Apis laboriosa and Apis dorsata are two species of giant honeybees distributed in Asia, and play important roles in their ecosystems. In this study, we analyzed the key factors affecting the distribution of two species, as well as their potential suitable areas and possible co-existence regional changes under the global climate change. We collected and filtered global distribution data of A. laboriosa and A. dorsata, then used eight climatic variables and Community Climate System Model version 4 (CCSM4) to simulate their potential suitable areas for the past, present and future (using two different climate scenarios) using MaxEnt. Finally, we used ArcGIS 10.2 and ENMTools to calculate range overlap and niche overlap of the two species in order to infer areas of co-existence. Temperature-related variables had the largest contribution to the model simulation. Among these variables, temperature seasonality (Bio 4) and mean temperature of coldest quarter (Bio 11) showed the strongest influence on the distributions of two giant honeybees. Under the current climate scenario, the species overlap in Nepal and Yunnan of China, with low niche overlap index. Between the last-glacial maximum to the present both honeybees moved northwest to their present range. A. laboriosa is projected to move to the northeast and A. dorsata may move southeast. Only 6.6% of overlapping distribution is currently protected, and further work is needed to protect these key areas.

Warning coloration provides a textbook example of natural selection, but the frequent observation of polymorphism in aposematic species presents an evolutionary puzzle. We investigated biogeography and polymorphism of warning patterns in the widespread butterfly Danaus chrysippus using records from citizen science ( n = 5467), museums ( n = 8864) and fieldwork ( n = 2586). We find that polymorphism in three traits controlled by known mendelian loci is extensive. Broad allele frequency clines, hundreds of kilometres wide, suggest a balance between long-range dispersal and predation of unfamiliar morphs. Mismatched clines for the white hindwing and forewing tip in East Africa are consistent with a previous finding that the black wingtip allele has spread recently in the region through hitchhiking with a heritable endosymbiont. Light/dark background coloration shows more extensive polymorphism. The darker genotype is more common in cooler regions, possibly reflecting a trade-off between thermoregulation and predator warning. Overall, our findings show how studying local adaptation at the global scale provides a more complete picture of the evolutionary forces involved.