Dung Beetle
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2022 ◽  
Vol 170 ◽  
pp. 104260
Renato Portela Salomão ◽  
Diego de Alcântra Pires ◽  
Fabricio Beggiato Baccaro ◽  
Juliana Schietti ◽  
Fernando Zagury Vaz-de-Mello ◽  

2021 ◽  
Julliana Barretto ◽  
Martha L Baena ◽  
Israel Huesca Domínguez ◽  
Federico Escobar

Abstract While theory suggests that at conception the sex ratio should be balanced (1:1), this can be variable across space and time in wild populations. Currently, studies of the environmental factors that regulate adult sex ratio (ASR) in species with different life-history traits are scarce. Using capture-recapture over a year, we analyzed the influence of habitat type (forest and non-forest) and season (rainy and dry) on variation in ASR, male aggregation and the trajectory movement of two dung beetle species with different life-history traits: Deltochilum mexicanum (a hornless roller species) and Dichotomius satanas (a tunneler species with horns on its head and thorax). We found opposite tendencies. The D. mexicanum population tends to be female-biased, but the population of D. satanas tends to be predominantly male, and observed values were not related to habitat type or season. However, the 95% confidence intervals estimated were highly variable between seasons depending on habitat. On examining the monthly variation in ASR for both habitats, we found that it depends on the species. In addition, male aggregation differed between species depending on habitat type and season, and species movement patterns were closely related to their habitat preferences. Based on our results, we argue that comparative population studies of species with different life-history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.

Victor Moctezuma ◽  
Gonzalo Halffter ◽  
Viridiana Lizardo

The Phanaeus tridens species group is revised and found to consist of twelve species: P. tridens Castelnau, 1840, P. moroni Arnaud, 2001 stat. rev., P. balthasari Arnaud, 2001 stat. rev., P. daphnis Harold, 1863, P. coeruleus Bates, 1887 stat. rev., P. herbeus Bates, 1887 stat. rev., P. substriolatus Balthasar, 1939 stat. rev., P. furiosus Bates, 1887, P. pseudofurcosus Balthasar, 1939 stat. rev., P. nimrod Harold, 1863, P. victoriae Moctezuma sp. nov., and P. eximius Bates, 1887. The majority of the name-bearing types of the group were revised. The neotype for P. tridens is suggested herein. The following junior subjective synonymies are recognized: P. frankenbergeri Balthasar, 1939 = P. tridens Castelnau, 1840, P. tricornis Olsoufieff, 1924 = P. herbeus Bates, 1887, and P. babori Balthasar, 1939 = P. nimrod Harold, 1863; while P. furcosus Felsche, 1901 = P. furiosus Bates, 1887 is recognized as a junior objective synonymy. The species within the P. tridens species group are diagnosed by the morphology of the pronotum and elytra, while the genital morphology of males is found to be homogeneous and uninformative for species delimitation. Most species within the group show a wide diversity of colouration (showing green, red, and blue chromatic phases). This probably led to taxonomical confusion by previous authors. Here, we present a new identification key, species distribution models. Habitus photographs and character illustrations for all the species within the group are provided. The climatic niches overlap widely in P. herbeus and P. daphnis, but the other species within the group show a reduced overlap in their climatic niches. Consequently, the P. tridens species group is proposed as a case of morphological stasis that might be explained by a trade-off between the evolution of pronotal structures and genitalia, while differences in the ecological niche might promote speciation.

The Holocene ◽  
2021 ◽  
pp. 095968362110604
Bert Kohlmann ◽  
Alfonsina Arriaga-Jiménez ◽  
Renato Portela Salomão

Several studies have tested the Elevational Rapoport Rule (ERR) in arthropods, especially in the Neotropical mountains. Nonetheless, different approaches should be used for a more nuanced comprehension of ERR patterns and assemblage altitudinal distribution patterns, such as the biogeographical, ecological, and evolutionary contexts. This study aims to test the ERR for elevational gradients in Mexican mountains. For this study, dung beetle assemblages of the genus Onthophagus were used as a model organism, and their distribution was studied in several different mountain ranges of the Mexican tropics. Altitudinal distribution of Onthophagus species was analyzed, including ecological traits and biogeographical/phylogenetical contexts as covariables. The increase of altitude was positively correlated to the assemblage altitudinal range. Furthermore, altitudinal range, relative abundance, body size, and mountain’s topographic prominence were positively correlated to the mean altitudinal range of Onthophagus species. Nonetheless, different altitudinal relationships were observed, depending on the mountain. The results support the idea that species that inhabit higher altitudes appear to be more environmentally plastic and occur in wider altitudinal ranges than species from lower altitudes, thus supporting the ERR. The present findings stress that biogeographical, ecological, phylogenetical, and historical aspects, besides body size, are essential drivers of the altitudinal distribution of Onthophagus dung beetles.

2021 ◽  
Vol 11 (1) ◽  
Honest Machekano ◽  
Chipo Zidana ◽  
Nonofo Gotcha ◽  
Casper Nyamukondiwa

AbstractTropical organisms are more vulnerable to climate change and associated heat stress as they live close to their upper thermal limits (UTLs). UTLs do not only vary little across tropical species according to the basal versus plasticity ‘trade-off’ theory but may also be further constrained by low genetic variation. We tested this hypothesis, and its effects on ecosystem function using a diurnally active dung rolling beetle (telecoprid), Allogymnopleurus thalassinus (Klug, 1855) that inhabits arid environments. Specifically, (i) we tested basal heat tolerance (critical thermal maxima [CTmax] and heat knockdown time [HKDT]), and (ii) ecological functioning (dung removal) efficiency following dynamic chronic acclimation temperatures of variable high (VT-H) (28–45 °C) and variable low (VT-L) (28–16 °C). Results showed that A. thalassinus had extremely high basal heat tolerance (> 50 °C CTmax and high HKDT). Effects of acclimation were significant for heat tolerance, significantly increasing and reducing CTmax values for variable temperature high and variable temperature low respectively. Similarly, effects of acclimation on HKDT were significant, with variable temperature high significantly increasing HKDT, while variable temperature low reduced HKDT. Effects of acclimation on ecological traits showed that beetles acclimated to variable high temperatures were ecologically more efficient in their ecosystem function (dung removal) compared to those acclimated at variable low temperatures. Allogymnopleurus thalassinus nevertheless, had low acclimation response ratios, signifying limited scope for complete plasticity for UTLs tested here. This result supports the ‘trade-off’ theory, and that observed limited plasticity may unlikely buffer A. thalassinus against effects of climate change, and by extension, albeit with caveats to other tropical ecological service providing insect species. This work provides insights on the survival mechanisms of tropical species against heat and provides a framework for the conservation of these natural capital species that inhabit arid environments under rapidly changing environmental climate.

Zootaxa ◽  
2021 ◽  
Vol 5067 (1) ◽  
pp. 122-128

The Onthophagus chevrolati Harold, 1869 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) species complex was recently studied, and a majority of its species were newly described or redescribed (see Moctezuma & Halffter 2020). Onthophagus viridichevrolati Moctezuma & Halffter, 2020 was the only species within the O. chevrolati species complex recognized to occur in the Mexican state of Jalisco (Moctezuma & Halffter 2020). Recently, new material belonging to the O. chevrolati species complex was collected from the maple (Acer; Sapindaceae) forests of Talpa de Allende, Jalisco, Mexico. The examination of these specimens showed that they are morphologically similar to O. chevrolati Harold, 1869 and belong to an undescribed species. In this study, we provide photographs of the habitus (male and female) and male genitalia of O. acernorus   new species; an identification key to separate it from O. chevrolati, and an updated distribution map of the O. chevrolati species complex.  

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