El progresivo aumento del turismo de aventura en el entorno de las dunas de Erg Chebbi, amenaza, desde hace casi dos décadas, la conservación del único complejo dunar (Erg) de todo Marruecos. Con el propósito de valorar algunos de los efectos de esta actividad sobre la comunidad de mamíferos locales, entre marzo y abril de 2018 se llevó a cabo un muestreo intensivo utilizando 5 métodos de detección distintos. El objeto principal era evaluar la presencia y distribución actual de las especies de mamíferos presentes, teniendo como referencia las citadas en la zona desde 1900 (Aulagnier et al., 2017). De las 16 especies históricamente citadas, 9 han sido detectadas en el presente trabajo, lo que representa un 56.2%. Resulta de interés la ausencia total de datos sobre 5 de las especies potencialmente más abundantes como son: Gerbillus amoenus (de Winton, 1902), Gerbillus gerbillus Olivier, 1801, Gerbillus tarabuli (Thomas, 1902), Pachyuromis duprasi Lataste, 1880 y Psammomys obesus Cretzschmar, 1828. Algunos datos apuntan a la drástica reducción de los recursos hídricos experimentada en los últimos años, como una de las causas de la aparente reducción de sus poblaciones. Al mismo tiempo, otras especies de requerimiento hídricos menores, tales como: Meriones libycus Lichtenstein, 1823 o Jaculus jaculus Linnaeus, 1758, presentan un aparente buen estado de conservación. Se confirma la presencia de Poecilictis libyca Hemprich & Ehrenberg, 1833, tras 32 años de ausencia de datos.
A new approach to landscape ecology involves the application of the eco-field hypothesis and the General Theory of Resources. In this study, we describe the putative eco-field of bark beetles as a spatial configuration with a specific meaning-carrier for every organism-resource interaction. Bark beetles are insects with key roles in matter and energy cycles in coniferous forests, which cause significant changes to forestry landscapes when outbreaks occur. Bark beetles are guided towards host trees by the recognition of semiotic signals using a specific eco-field. These signals mainly comprise a group of scents, which are called the odourtope. Their interactions with other organisms (fungi, bacteria, nematodes, predators, etc.) occur by sharing relevant information from the eco-field networks (representamen networks) in the forest ecosystem. The eco-field networks modulate the expansion of the realized semiotic niche of the bark beetle towards the potential semiotic niche. Moreover, the niche construction process can be initiated by interchanging signals among species living in the same place, where these signals allow the exploitation of the required resources. If different organisms are interdependent on signals in eco-field networks, then this process may result in the establishment of mutualistic relationships. This is an example of how evolutionary processes are initiated by the recognition of signals in a network of eco-fields.
Cosmodela Rivalier, 1961, represents a genus of tiger beetles that currently contains 13 described species widely distributed across Southeast Asia. A phylogenetic analysis based on the mitochondrial DNA fragments 16S and COI and the nuclear marker wingless and a phylogeographic analysis using a COI fragment were carried out on two subspecies of Cosmodela aurulenta (C. a. juxtata and C. a. aurulenta). The results support the hypothesis that these two subspecies are significantly different to be considered as separate species that diverged during the Pleistocene. TAXONDNA analysis was used to investigate the capability of the COI region as a marker for discriminating both entities and to quantify intra‐ and intertaxa genetic variation. The minimum distance between C. aurulenta and C. juxtata was 2.7837%, and no overlap of intra‐ and intertaxa genetic divergence was observed. Both taxa, here considered as valid species, occur in sympatry in the Malay Peninsula, with C. aurulenta most probably originating from the area and C. juxtata a secondary colonizer that expanded southwards from the Asian mainland. Our data infer a continental origin of the Indonesian samples of C. aurulenta, and they most likely dispersed across the land bridges that emerged during glacial maxima to form Sundaland.
South–east Iberia is the southernmost limit of this species in Europe. Squirrels in the region mainly inhabit coniferous forests of Pinus. In this study, we analyzed the pattern of mitochondrial genetic variation of southern Iberian red squirrels. Fragments of two mitochondrial genes, a 350–base pair of the displacement loop (D–loop) and a 359–bp of the cytochrome b (Cytb), were sequenced using samples collected from 88 road–kill squirrels. The genetic variation was low, possibly explained by a recent bottleneck due to historical over–exploitation of forest resources. Habitat loss and fragmentation caused by deforestation and geographic isolation may explain the strong genetic subdivision between the study regions. Six new haplotypes for the D–loop and two new haplotypes for the Cytb fragments are described. A Cytb haplotype of south–east Iberia was found to be present in Albania and Japan, suggesting local extinction of this haplotype in intermediate areas. No significant clustering was found for the south–east of Spain or for the other European populations (except Calabria) in the phylogenetic analysis.
Meiotic behavior based on observations of the first and second divisions was studied in males of four taxa of the Australian tiger beetle genus Pseudotetracha of the tribe Megacephalini (Coleoptera). Pseudotetracha blackburni clade 1 shows 10 pairs of autosomes plus a trivalent that is hypothesized to be the result of either a translocation or a fusion in which the original heterosomes (very likely XY) and an autosomal pair are involved, giving rise to a recently established neo-X1X2Y sex chromosome system of chiasmatic nature. The origin of this karyotype has been determined to have taken place 2.30–3.72 million years in the past using a molecular clock based on the 16S rRNA substitution rate. Pseudotetracha blackburni clade 2 shows a meioformula of the type n = 11 + XY, the same as that found in the related taxon P. australis. Previous data for P. whelani, with 12 pairs of autosomes and an XY sex chromosome system, are confirmed in this survey. The multiple chiasmatic sex chromosome system of P. blackburni clade 1 is considered to be of recent origin and with an evolutionarily short-life confined to this species, where close relatives exhibit simple genetic systems, in contrast to the long evolutionary life of the multiple achiasmatic sex chromosome system broadly found in the tribes Cicindelini and Collyrini. The implications of this chromosomal rearrangement in terms of recombination and speciation are discussed. The results of this work, together with the available cytogenetic data for other Megacephalini species, are interpreted in the light of recent molecular phylogenies of the tribe, showing evidence of a possible process of karyotypic orthoselection with recurrent cycles of incorporation of autosomes to the heterosome pair and subsequent loss of the Y chromosome in Tetracha and Pseudotetracha.
Our phylogenetic analysis of three endemic species of the Australian tiger beetle genus Pseudotetracha (Fleutiaux, 1864) from South Australia used sequences of two fragments of the mitochondrial genes 16S rRNA and cytochrome oxidase III. A matrix for each gene and two combined matrices were constructed. We compared these three riparian species, together with data from nine taxa of this genus available in GenBank, using parsimony and Bayesian methods. These molecular results are in agreement with the phylogenetic hypothesis for the blackburni/murchisona species complex previously proposed based on morphology, whereas other recent molecular analyses have questioned the existence of this species complex. In all of our analyses, samples of P. blackburni divided into two statistically supported clades, one of which is more closely related to P. mendacia and P. pulchra than to the other P. blackburni clade. This suggests the existence of a cryptic new species. Additionally, we analysed chromosomes of the second metaphase cells of members of the two clades. The observations showed different karyotypes as blackburni-1 has two types of second meiotic metaphase cells with 11 and 12 chromosomes, whereas in blackburni-2, all cells have 12 chromosomes, adding evidence for the putative existence of two species. Resumen Nuestro analisis de tres especies del genero endemico australiano Pseudotetracha Fleutiaux, 1864 recolectadas en Australia del Sur usa secuencias de dos fragmentos de los genes mitocondriales ARNr 16S y citocromo oxidasa III. Fue construida una matriz para cada gen y otras dos matrices combinadas. Comparamos estas tres especies riparias junto con datos de nueve taxones de este genero disponibles en la base de datos GenBank, por medio de metodos de parsimonia y bayesianos. Los resultados moleculares se muestran de acuerdo con la hipotesis filogenetica acerca del complejo de especies blackburni/murchisona propuesto previamente en base a la morfologia, mientras que otros estudios moleculares mas recientes han cuestionado la existencia de este complejo de especies. En todos los analisis, las muestras de P. blackburni se dividen en dos clados con soporte estadistico, separados por las secuencias de P. mendacia y P. pulchra, hecho que sugiere la existencia de una nueva especie criptica. Adicionalmente se han analizado cromosomas en celulas de la segunda division de la meiosis en miembros de ambos clados. Las observaciones mostraron cariotipos diferentes, asi blackburni-1 presento dos tipos de celulas en la segunda division meiotica con 11 y 12 cromosomas respectivamente, mientras que en blackburni-2 todas las celulas mostraron 12 cromosomas, proporcionando asi evidencias adicionales que apoyan la posible existencia de dos especies.
The chromosomes of 26 taxa from Mexico of the tribes Passalini (three species) and Proculini (23 species) have been studied, increasing the karyotypically known species of the family Passalidae to 56. Karyotypic dynamism is high since the diploid number varies from 18 to 44 in the tribe Proculini. and from 25 to 31 in the tribe Passalini. In addition, supernumerary chromosomes, chromosome heteromorphism, translocations and possible sex multivalents have been found. These results contrast with the numerical conservatism found in related families of the superfamily Scarabaeoidea. However, both tribes are conservative with regard to sex determination, as all species of Proculini have male XY chromosomes whereas species of the Passalini have male XO chromosomes. It is postulated that differences in patterns shown by these two tribes are mainly due to population structure, because many species of Proculini are endemic to restricted areas of Meso and South America, favouring the settlement of karyotypic changes, whereas species of Passalini are distributed over large areas in the lowlands. It is also postulated that the ancestral karyotypic formula of the family is close to 12–14 pairs of autosomes although the ancestral male sex determination may be either XY or XO. At present only a weak relationship between morphological and karyotypic evolution has been found, which together with the marked numerical variability found within and between genera make it difficult to obtain phylogenetic conclusions from karyotypic results.
The major ribosomal DNA (rDNA) loci were localized on meiotic and mitotic chromosomes and in interphase nuclei of 18 ground-beetle species belonging to three tribes of the supertribe Carabitae by fluorescence in situ hybridization (FISH), using a PCR-amplified 18S rDNA as a probe. Meiotic observations indicate that the 18S rDNA sequences are located on the largest autosomal bivalent in 12 species of Carabus, two species of Calosoma (both genera belonging to the tribe Carabini), and three sibling species of Ceroglossus chilensis (tribe Ceroglossini). The data suggest the occurrence of a conservative pattern in these three genera despite the chromosomal rearrangements that have led to karyotypes with higher chromosome numbers in Ceroglossus. A different result is found in Cychrus caraboides (tribe Cychrini), where ribosomal cistrons are located in two medium-sized autosomal pairs. Further species of Cychrini should be studied for corroborating the occurrence of molecular and karyotypical apomorphies in Cychrus with regard to the genera Carabus, Calosoma and Ceroglossus.
The Mediterranean pine shoot beetle Tomicus destruens is one of the most damaging bark beetles attacking Mediterranean pine forests in southern Europe and north Africa. We studied the attractiveness of the host volatiles alpha-pinene and ethanol at a range of release rates, alone or in combination, to T. destruens, in order to develop an attractive lure for the management of this beetle. T. destruens was attracted slightly to the host volatile alpha-pinene, but a strong synergistic effect was found in the attraction towards monoterpene when ethanol was added to the bait. The highest catches of T. destruens were obtained by the optimal blend releasing 300 mg/day of alpha-pinene and 900 mg/day of ethanol. In contrast to data reported for the related species T. piniperda, Mediterranean pine shoot beetles were clearly attracted to baits releasing ethanol alone (1350 mg/day). trans-Verbenol, which was also added to host volatiles in some tests, did not affect the response. The use of the attractive blend proposed would have a low impact on the natural enemy population of Thanasimus formicarius because of asynchronies in flight periods. Other non-target insects, such as the facultative predator or competitor Oxipleurus nodieri, were also significantly attracted. These results allow the development of an operative lure for the effective monitoring of T. destruens, although improvements by the addition of other host volatiles should be studied.
An extensive survey of mitochondrial haplotypes in honeybee colonies from the Iberian Peninsula has corroborated previous hypotheses about the existence of a joint clinal variation of African (A) and west European (M) evolutionary lineages. It has been found that the Iberian Peninsula is the European region with the highest haplotype diversity (12 haplotypes detected of the M lineage and 10 of the A lineage). The frequency of A haplotypes decreases in a SW-NE trend, while that of M haplotypes increases. These results are discussed in relation to hypotheses about the African origin of Apis mellifera and an early colonization of west Europe during intermediate Pleistocene glaciation events, followed by a regional differentiation. The extant pattern of haplotype frequency and distribution seems to be influenced at a regional scale by adaptation to local climatic conditions and the mobile beekeeping that has become a large-scale practice during the last decades. Other previous anthropogenic influences (Greek, Roman and Arab colonizations) are thought to be of minor importance in present day populations.
We investigated here the relation of environmental variables with the distribution of mitochondrial lineages using a bark beetle species of Mediterranean distribution as a model. We analysed a total number of 460 DNA sequences of Tomicus destruens provided by intensive and extensive collection and GenBank entries. We combined phylogeography and regression models to study the role of five environmental predictors at fine scale in the distribution of a local genealogy. The analysis revealed a high genetic diversity, with 52 haplotypes present in Sierra Espuna forest (SE Spain) and 21 haplotypes in the other 14 Spanish populations, all included in the western clade of the Mediterranean phylogeography of the species. We found a micro-distribution of the species related to altitude and putative niche segregation between lineages associated with the micro-environmental conditions of their host pine trees. We compared the phylogeographic hypothesis obtained here with the phylogeography obtained integrating our data with all data published elsewhere. Here, we demonstrate a relation between the environmental heterogeneity and the haplotypic diversity at Mediterranean Basin scale. This analysis allows us to support the evolutionary scenario where the phylogeography and current molecular diversity of T. destruens is a consequence of the recolonization from two principal refugia at both extremes of the Mediterranean Basin and, according to our data, we propose that the heterogeneity of habitats allows fixation of the mitochondrial lineages.
Mycoplasma agalactiae is the main causal agent of contagious agalactia syndrome in Spain. It is a severe disease of small ruminants, endemic in Mediterranean countries, that is characterized by mastitis, arthritis, and keratoconjunctivitis. This paper investigates the temporal, spatial, and host-related factors in the distribution of M. agalactiae infection from October 1996 to November 1998 and March 2002 to May 2003 in Spanish ibex (Capra pyrenaica) populations from Andalusia, in southern Spain. The predisposing factors to infection among previously selected factors (year of sampling, climatic season, geographic origin according to province, mountain range and metapopulation, sex, year of life, presence of scabies, and phase of the reproductive cycle) were established. We collected conjunctival and ear-canal swabs from 411 free-ranging ibexes. The frequency of infected ibexes was 11.2%. The peak frequency of infection occurred in 1998 and in summer. Granada was the province with greatest risk (odds ratio=2.6) of carriers (18.8% infected). The predisposing factors were sex (females), age (young animals), and metapopulation (Sierra Nevada). We identified a higher number of infected ibexes in the metapopulation "Sierra Nevada" (34/256) and significant differences among the three established metapopulations (P<0.01). Mycoplasma agalactiae infection represents a risk for population density and maintenance of these wild populations; infections can result in blindness, malnutrition, and polyarthritis leading to numerous deaths.
Saline inland waters are globally threatened habitats harbouring many specialised endemic species, which often have restricted geographic ranges, and occur as highly isolated populations. We studied the genetic variation and phylogeography of Ochthebius glaber Montes and Soler, a rare and endangered water beetle endemic to hypersaline streams in the South and Southeast of the Iberian Peninsula. We used a 633 bp fragment of cytochrome oxidase subunit 1 gene to determine the genetic diversity and phylogeographic structure within this species, and interpret this in the light of the speciesȁ9 conservation requirements. Thirteen populations were sampled across the speciesȁ9 geographic range, and genetic diversity found to be very high, with 37 haplotypes across the 71 specimens examined (p-distance 0.2–7.3%, average 3.1±0.4). Phylogeographic analyses revealed a surprisingly high degree of geographical structure, detectable among populations separated by relatively short geographical distances, with three main groups of haplotypes which have apparently been isolated for significant periods of time. Past fragmentation and contiguous range expansion events were inferred as the main causes of the detected geographical associations of haplotypes. The establishment of independent evolutionary lineages as conservation units is particularly important for species inhabiting saline habitats such as O. glaber, which is endangered by habitat loss across most of its distribution. However, given the natural instability of hypersaline environments, the conservation of a network of populations and potential habitats would be necessary to enable the preservation of the process generating and maintaining the diversity of the species.
The molecular diversity of the honey bee Apis mellifera in the province of Buenos Aires (Argentina) has been analysed through the study of the mitochondrial DNA. The mitochondrial haplotype corresponding to the intergenic region tRNA(leu)-COII has been determined in samples from 300 colonies from 150 apiaries distributed in 71 localities of the province of Buenos Aires. Eight different haplotypes have been found, four of the African, three of the West European and one of the East European evolutionary lineages. The frequency of these haplotypes corroborates that the European yellow honey bee Apis mellifera ligustica is predominant in the Buenos Aires province whereas the black European bee A. m. mellifera is rare. The presence of the African haplotypes A I and A4 common in Africanized honey bees, confirms a border of the africanization process located around the 30 degrees-35 degrees SL parallels. The other two African haplotypes (A8 and AII) are indicative of an Iberian or North African origin of some colonies. The influence of the transhumance and beekeeping practices is discussed in relation to the genetic variability detected.
Fifteen years after the publication of the first genomic sequence of a phytophagous beetle, we review here the wealth of genetic and genomic information generated so far for the species-rich beetle superfamilies Chrysomeloidea (longhorn, seed and leaf beetles) and Curculionoidea (weevils and bark beetles).In this review we briefly describe the most common methods used to investigate the beetle genomes and also compile the nucleotide sequence information stored in public gene databases until December 2004.The motivations and relevance of these research initiatives are described in certain detail, distinguishing among structural and population studies, phylogenetic research, the study of genes involved in development and diapause, energetic metabolism, vegetal tissue digestion, and genes for insect resistance and defence.
The molecular variability has been analysed at the mitochondrial level in 288 honeybee colonies from 28 localities distributed along the four Catalonian provinces. In total sixteen different haplotypes belonging to three evolutionary lineages were found. The west European M lineage has been found at a high frequency in the four provinces and is fixed in Lerida, whereas the African A lineage shows a cline of distribution being more frequent in the northern Catalonia. The east European C lineage has been found in three colonies (one in Gerona and two from Barcelona). These results are most likely attributable to natural evolution events but the human influence should also be considered as an agent causing recent changes in the distribution of the honeybee populations. New insights about the evolution of the honeybee populations from the Iberian Peninsula are discussed in the light of the new information provided.
SUMMARY The mitochondrial DNA of 260 honey bee (Apis mellifera) colonies located in eastern Spain was characterized through the RFLP analysis of the intergenic tRNAleu-COII region. In total, 16 different mitochondrial haplotypes were found, eight of which belong to the African evolutionary lineage and eight to the west European. The results indicate a high level of genetic diversity in this region. The haplotype frequency is congruent with a north-east-south-west gradient extending across the whole Iberian peninsula. Several beekeeping techniques (transhumance movements, purchase of queens and colonies) and recent laws about colony location are discussed in relation to the biodiversity of this honey bee population.
Meiotic chromosomes of eight Neotropical species of the genus Chauliognathus occurring in Southern Brazil were analysed from testis cells. The meioformula of all the species was n = 6 + X (with six pairs of autosomes and one X chromosome). This meioformula is also present in C. scriptus plus two other species of other genera of Cantharidae, suggesting an evolutionary tendency towards the compaction of the karyotype starting from the ancestral Polyphagan meioformula n = 9 + Xy(p). The presence of an XO sex chromosome mechanism in all cantharid species studied to date indicates that the reduction of the number of autosomes was probably paralleled by the loss of the small typical Polyphagan yp heterosome. Thus the meioformula n = 6 + X seems to be an apomorphy for Cantharidae and may have evolved soon after the separation of the ancestral cantharid from the other families of Polyphaga.
The genus Zabrus Clairville, 1806 is a Holomediterranean taxon that radiated into about a hundred species most likely during the Cenozoic.There are four endemic subgenera on the Iberian Peninsula, which include 28 species, Epomidozabrus (3 spp.), Euryzabrus (1 sp.), Platyzabrus (2 spp.) and Iberozabrus (22 spp.).A mitochondrial fragment comprising part of the cytochromeoxidase-I, tRNAleu, and part of the cytochrome-oxidase-II genes was sequenced of most of these species.Taxa of other subgenera of Zabrus (Macarozabrus, Polysitus, Zabrus, and Pelor), six species of Amara (the putative sister taxon of Zabrus), and representatives of tribes related to Zabrini were also sequenced.The results show that the genus Zabrus is a monophyletic taxon well separated from Amara.The four subgenera endemic to the Iberian Peninsula also make up a monophyletic clade, which stresses the association between the geographic distribution and the monophyly of many supraspecific taxa within this genus.The species-rich subgenus Iberozabrus seems to be the sister taxon of the clade made up of the three other subgenera endemic to the Iberian Peninsula.The Iberozabrus species-groups proposed by Andújar & Serrano in 2001, based on morphological and geographical grounds, are only partly corroborated by the molecular phylogeny.The lack of congruence between these data sets is mainly between those speciesgroups with large numbers of species and more complex geographic patterns.Some cases of incongruence are possibly due to homoplasic external characters appeared by convergent evolution.
Aim, Location Tomicus (Coleoptera, Scolytidae) species are some of the principal pests of Eurasian forest and are represented by three coexisting species in Spain, Tomicus piniperda (Linnaeus, 1758), Tomicus destruens (Wollaston, 1865) and Tomicus minor (Harting, 1834). The distribution of two taxa are unknown as they have until recently been considered separate species. Therefore, we model the potential distribution centres and establish the potential distribution limits of Tomicus species in Iberia. We also assess the effectiveness of different models by comparing predicted results with observed data. These results will have application in forest pest management.Methods Molecular and morphological techniques were used to identify species from 254 specimens of 81 plots. For each plot, a Geographical Information System was used to extract a set of 14 environmental (one topographic, six climatic) and biotic variables (seven host tree distributions). General Additive Models and Ecological Niche Factor Analysis models are applied for modelling and predicting the potential distribution of the three especies of Tomicus.Results The results of both modelling methodologies are in agreement. Tomicus destruens is the predominant species in Spain, living in low and hot areas. Tomicus piniperda occurs in lower frequency and prefers wet and cold areas of north-central Spain. We detected sympatric populations of T. destruens and T. piniperda in Northern coast of Spain, infesting mainly P. pinaster. Tomicus minor is the rarest species, and it occupies a fragmented distribution located in high and wet areas. The remarkable biotic variable is the distribution of P. sylvestris, incorporated into the models of T. destruens and T. piniperda.Main conclusions These results indicate that in wet areas of north-central Spain where T. piniperda occurs (and possibly the high altitudes of the southern mountains), T. destruens has a climatic distribution limit. In the northern border of this area, both species overlap their distributions and some co-occurrences were detected. Tomicus minor potentially occurs in high and wet fragmented areas.