Distribution patterns and habitat preference for the genera-group Blepharida s.l. in Sub-Saharan Africa (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

Up and down from North to South: Latitudinal Distribution of Flea Beetle Genera in Continental Africa (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

The distribution of global biodiversity can be investigated based on comprehensive datasets and many methods to process them. The taxonomic diversity of phytophagous insects is typically linked to plant diversity, which increases from temperate to tropical latitudes. In this paper, we explored the latitudinal distribution of the flea beetle genera (Coleoptera, Chrysomelidae, Galerucinae, Alticini) on the African continent. We divided the area into latitudinal belts and looked for possible correlations with the number and types of vegetational divisions, the area of each belt, and the bioclimatic variables. The number of flea beetle genera is related to the number and types of vegetation divisions rather than the area of each belt. Some bioclimatic variables are highly related to the number of genera, which is higher within those belts where climate factors limit the oscillation of temperature over the year and favor high precipitations, especially in the warmest months. These biotic and abiotic factors lead to a two-peak trend in the taxonomic richness of flea beetle genera from north to south. Genera endemic to restricted areas are linked to the presence of high mountain systems and increase the taxonomic richness of the belt they belong to.

Climatic Niche, Altitudinal Distribution, and Vegetation Type Preference of the Flea Beetle Genus Arsipoda in New Caledonia (Coleoptera Chrysomelidae)

New Caledonia is one of the major biodiversity hotspots. The flea beetle genus Arsipoda (Coleoptera Chrysomelidae) is present with 21 species, all endemic. We investigated, using GIS analyses and ecological niche models, the habitat preferences of these species in terms of vegetation types, altitude, and climate, and assessed the adequacy of knowledge on the spatial parameters affecting the distribution of the genus in New Caledonia. Altitude and geology seem to play an important role in shaping species distribution. Volcanic substrate allows the growth of ultramafic vegetation, which includes most of their host plants. From a biogeographic and conservation perspective, our results report a deep link between Arsipoda species and their habitats, making them particularly sensitive to environmental modifications.

Taxonomy, Habitat Preference, and Niche Overlap of Two Arrow-Poison Flea Beetle Species of the Genus Polyclada in Sub-Saharan Africa (Coleoptera, Chrysomelidae)

Simple Summary

The taxonomy of many African Coleoptera species is remains poorly known, and the knowledge of their ecological requirements is worse still. Starting with original data, we describe morphological differences and ecological data for two flea beetle species, Polyclada bohemani and P. pectinicornis, which traditionally have been used by the Bushmen people in sub-Saharan Africa to poison their arrows. Moreover, we evidence differences in the formations of vegetation used by these two species, which are known to occur mainly in savannah and open forest habitats. Also, we identify differently suitable areas in terms of climatic preferences, in addition to a common territory in East Africa. We also supply, for the first time, the description of the shape of the aedeagus and the spermatheca of both species, supplying important new diagnostic characters for their identification.

Abstract

Coupling the geographic distribution and the ecological requirements of species often supports taxonomy and biogeography. In this contribution, we update the distribution of two flea beetle species of ethno-entomological interest, Polyclada bohemani and P. pectinicornis, by analyzing original data. In addition, we supply their main morphological diagnostic characters, describing their aedeagal and spermathecal shapes for the first time. We also assess their niche differences in terms of climatic and vegetation needs, by means of ecological niche modelling and remote sensing techniques. Several new localities were identified to improve knowledge of the geographical distribution of both species. Moreover, we located a wide climatic suitability overlap in East Africa for these two flea beetle species, while in other areas they show a clear separation. Our analysis also reports that P. bohemani is associated with areas of denser tree cover than P. pectinicornis. Finally, the lectotypes of Diamphidia bohemani Baly, 1861, Clytra pectinicornis Olivier, 1791, and Diamphidia compacta Fairmaire, 1887 are here designated and the new synonymy Clytra pectinicornis Olivier = Diamphidia compacta Fairmaire syn.nov. is proposed.

Calotheca nigromaculata species-group from sub-Saharan Africa with descriptions of two new species from KwaZulu-Natal (Chrysomelidae, Galerucinae, Alticini)

Calotheca Heyden is a flea beetle genus with a largely sub-Saharan distribution and currently comprising 34 species. The examination of new material is revealing an increase in species richness and intraspecific variability. Calotheca carolineaesp. nov. and C. wanatisp. nov., both from KwaZulu-Natal in the Republic of South Africa, are here described and attributed to the C. nigromaculata (Jacoby) species group, mainly based on genitalic characters. Photographs of the main diagnostic characters are provided, including the habitus, median lobe of the aedeagus, and spermatheca. Information on the geographic distribution and host plants of these species is also provided.

DBSCAN and GIE, Two Density-Based "Grid-Free" Methods for Finding Areas of Endemism: A Case Study of Flea Beetles (Coleoptera, Chrysomelidae) in the Afrotropical Region

Areas of endemism (AoEs) are a central area of research in biogeography. Different methods have been proposed for their identification in the literature. In this paper, a "grid-free" method based on the "Density-based spatial clustering of applications with noise" (DBSCAN) is here used for the first time to locate areas of endemism for species belonging to the beetle tribe Chrysomelidae, Galerucinae, Alticini in the Afrotropical Region. The DBSCAN is compared with the "Geographic Interpolation of Endemism" (GIE), another "grid-free" method based on a kernel density approach. DBSCAN and GIE both return largely overlapping results, detecting the same geographical locations for the AoEs, but with different delimitations, surfaces, and number of detected sinendemisms. The consensus maps obtained by GIE are in general less clearly delimited than the maps obtained by DBSCAN, but nevertheless allow us to evaluate the core of the AoEs more precisely, representing of the percentage levels of the overlap of the centroids. DBSCAN, on the other hand, appears to be faster and more sensitive in identifying the AoEs. To facilitate implementing the delimitation of the AoEs through the procedure proposed by us, a new tool named "CLUENDA" (specifically developed is in GIS environment) is also made available.

Habitat Specificity, Host Plants and Areas of Endemism for the Genera-Group Blepharida s.l. in the Afrotropical Region (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

Simple Summary

Knowledge of the processes that generate biodiversity is a core-issue of any conservation strategy because it allows predicting the effects of environmental changes in the number and distribution of target taxa. Some phytophagous insects can be good potential indicators of such processes, thanks to their wide distribution and their sensitivity to climate change, due to the association with specific environments and host plants. Unfortunately, this ecological information is often lacking. However, statistical tools allow reconstructing the ecological features of interest, based on the presence–absence data of the taxa, the climatic and vegetational features of their distributional areas, and the available data about their host plants. In this paper, we apply some geostatistical methods to identify processes and patterns of biodiversity at a continental scale, focusing on a group of phytophagous insects widespread in sub-Saharan Africa.

Abstract

The genus Calotheca Heyden (Chrysomelidae) is mainly distributed in the eastern and southern parts of sub-Saharan Africa, with some extensions northward, while Blepharidina Bechyné occurs in the intertropical zone of Africa, with two subgenera, Blepharidina s. str. and Blepharidina(Afroblepharida) Biondi and D’Alessandro. These genera show different ecological preferences. Through an up-to-date presence–absence dataset, in the light of the terrestrial ecoregions of sub-Saharan Africa and the distribution of their possible host plants, we interpreted the pattern of occurrence of these three supraspecific taxa, by geostatistical analyses in GIS and R environments. The separation of Blepharidina from Calotheca was probably driven by changes in climate as adaptation to more xeric and warm environments with a major occupancy of semidesert and savannah habitats, especially in the Afroblepharida species. Based on our data and analyses, Calotheca is mainly associated with Searsia (Anacardiaceae), and Blepharidina is likely associated with Commiphora (Burseraceae). This hypothesis is also corroborated by the widespread and even dominance of the Commiphora plants in the ecoregions where both Blepharidina s.str. and, above all, Afroblepharida, are more common. The main areas of endemism of the two genera are also differently located: Calotheca in the temperate zone; Blepharidina within the intertropical belt.

Phylogenetics and population structure of the steppe species Hycleus polymorphus (Coleoptera: Meloidae: Mylabrini) reveal multiple refugia in Mediterranean mountain ranges

Many continental species distributed in the Eurasian steppe occur as relict populations in the mountains of Western Europe. Their biogeographical responses to Quaternary climate changes have been poorly studied; however, they could have responded as cold-adapted species. We investigated the biogeographic history of a steppe beetle, Hycleus polymorphus, using mitochondrial and nuclear DNA sequences (COI, CAD, ITS2), and species distribution modelling (SDM) under present and past bioclimatic envelopes. We first performed a phylogenetic assessment to define species boundaries within the H. polymorphus species group. Specimens previously treated as Hycleus humerosus on morphological grounds are assigned to H. polymorphus, and those identified as Hycleus zebraeus assigned to Hycleus atratus. ITS2 data analyses revealed a strong phylogeographical structure of H. polymorphus populations, with four haplogroups corresponding to the (i) Italian Alps, (ii) French Alps and Pyrenees, (iii) South Balkan and Pontic mountains, and (iv) North Dinaric Alps. Based on these analyses and the SDM, we propose that during a glacial period, following the spread of steppic habitat, H. polymorphus underwent a range expansion from Asia to South-West Europe. Within the Mediterranean area, during the last interglacial the climatic suitability for the species was limited to mountains that acted as refugia and prompted allopatric divergence into four main lineages.

Investigating the Current and Future Co-Occurrence of Ambrosia artemisiifolia and Ophraella communa in Europe through Ecological Modelling and Remote Sensing Data Analysis

The common ragweed Ambrosia artemisiifolia has spread throughout Europe since the 1800s, infesting croplands and causing severe allergic reactions. Recently, the ragweed leaf beetle Ophraella communa was found in Italy and Switzerland; considering that it feeds primarily on A. artemisiifolia in its invaded ranges, some projects started biological control of this invasive plant through the adventive beetle. In this context of a ‘double’ invasion, we assessed the influence of climate change on the spread of these alien species through ecological niche modelling. Considering that A. artemisiifolia mainly lives in agricultural and urbanized areas, we refined the models using satellite remote-sensing data; we also assessed the co-occurrence of the two species in these patches. A. artemisiifolia is predicted to expand more than O. communa in the future, with the medium and high classes of suitability of the former increasing more than the latter, resulting in lower efficacy for O. communa to potentially control A. artemisiifolia in agricultural and urbanized patches. Although a future assessment was performed through the 2018 land-cover data, the predictions we propose are intended to be a starting point for future assessments, considering that the possibility of a shrinkage of target patches is unlikely to occur.