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Genetic structure of a population can be molded by the resistance of the landscape or the distance between populations that function as barriers to gene flow. We analyzed the population genetic structure of Abies religiosa on a fine spatial scale and examined isolation models by resistance and distance. We collected vegetative tissue from populations located at the altitudinal extremes of the distribution range of the species on three slopes of La Malinche National Park (LMNP) (South, North, and East) in central Mexico. Genomic DNA was obtained using the CTAB 2X method, and eight microsatellite chloroplast loci were amplified. The genetic structure was identified based on an Analysis of Molecular Variance, a Discriminant Analysis of Principal Components with cross-validation and a spatial Principal Component Analysis using the Gabriel-type connectivity network. The isolation hypotheses were evaluated by constructing partial Mantel tests using Reciprocal Causal Modeling and Maximum Likelihood Population Effects models. A genetic structure of isolation by resistance to elevation was identified, and two genetic groups were recognized: one including populations of the South slope and the other comprising populations of the North and East slopes. We detected in Abies religiosa populations of the LMNP an isolation by resistance to elevation that determines the genetic structure, and the greatest genetic exchange between groups of populations located at higher altitudes. It is suggested to promote the connectivity between slopes through assisted migration and immediately halt land-use changes, as part of the actions to preserve genetic diversity in the LMPN. This study contributes to the knowledge of the spatial genetic structure of species at risk in the Mexican temperate forest for their conservation. [ABSTRACT FROM AUTHOR]

In this study, we examined whether the genetic diversity of Didelphis marsupialis is structured or their populations maintain high gene flow as expected in common species. Forty-eight Tomahawk traps were set for four consecutive nights in The Highlands and the Central Depression, State of Chiapas, Mexico. Eight microsatellites were amplified to examine genetic diversity. Genetic structure was evaluated in terms of the null allele-corrected pairwise global Fst estimates, according to the ENA and INA methods. An Analysis of Molecular Variance and a Bayesian analysis were carried out classifying the opossums by region and population. We found a moderate genetic diversity (He = 0.57–0.62) and an intermediate genetic differentiation between population (Fst = 0.11, P = 0.009). Genetic distances showed a closer relationship between individuals from populations that had a similar disturbance level. The Bayesian analysis showed a marked structure both between regions and between populations. Our results show in the common opossum moderate levels of gene flow, limited possibly by the habitat fragmentation due to anthropogenic disturbance. Further genetics studies and conservation efforts on this marsupial are recommended. Our findings are relevant for the conservation of common marsupial species in Mexico. [ABSTRACT FROM AUTHOR]

Male mating success depends on various traits and factors, and correctly identifying these traits can be key in the context of pest management. For tephritid pests, controlled through the sterile insect technique (SIT) traits, such as male size, can be manipulated through mass-rearing procedures. Thus, it is particularly important to understand whether male size can favor mating success. Here, we evaluated mating success of males of different sizes in Anastrepha ludens and Anastrepha obliqua, two species controlled through SIT. For both species, a morphometric analysis was performed of mated and unmated mass-reared and wild males in field cages. In both A. ludens and A. obliqua, wild females did not discriminate their mates based on male size and mated more frequently with wild males regardless of size. For mass-reared males, we found no evidence of an advantage of the large males compared to small males in mating success. However, we did find differences between the morphometric traits of mass-reared and wild males. In A. ludens, traits associated to mating success were Face Width (FW), Head Width (HW), Thorax Length (TL) and Wing Length (WL), and for A. obliqua were FW, HW, WL and WW (Wing Width). Overall, FW and TL were more consistent predictors of mating success. In conclusion, female choice seems to suggest multivariate selection, confirming that overall body size (expressed as pupal diameter, which is highly correlated with weight) is not a decisive factor in male mating success in these two species. However, morphological traits such as FW, HW, TL, WL and WW may be relevant in mating preference of wild female. [ABSTRACT FROM AUTHOR]

The knowledge of the diversity and genetic structure of pest insects under management contributes to the improvement of control strategies. An experiment was run to investigate whether the addition of the fungus Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) (BB) and compost to soil affects the presence and genetic diversity of adults and larvae of Phyllophaga obsoleta Blanch (Coleoptera: Melolonthinae) larvae in maize crops. We collected adults in and used mating pairs under four treatments (BB, compost, soil, blank). Genetic diversity and structure were determined through five allo/iso-enzymatic loci. Beauveria bassiana affected the presence and mortality of P. obsoleta in the laboratory but not under field conditions. The genetic diversity of P. obsoleta ranged from moderate to high (Ho = 0.26–0.31), with a low genetic differentiation among localities or treatments (Phi < 0.05), indicating high levels of gene flow. Our results showed a weak effect of B. bassiana on P. obsoleta in the field. Still, our laboratory observations suggest that the fungus may be a suitable alternative for biological control. [ABSTRACT FROM AUTHOR]

We studied the population viability of two common marsupials, Didelphis marsupialis and Didelphis virginiana, based on field data and published ecological and genetic information. Using the VORTEX v. 10. 2.6 program, a 100-year simulation was performed with 1000 iterations for five populations of D. marsupialis and six of D. virginiana. A low probability of extinction was observed in both species, particularly for D. virginiana (0.000–0.007). Population size is higher considering a metapopulation dynamics approach versus individual populations for the two marsupials: 498.25 individuals for D. marsupialis and 367.41 individuals for D. virginiana. The estimated mean genetic diversity was high for both D. marsupialis (He = 0.77–0.78) and D. virginiana (He = 0.79–0.82). The survival of both species over time could be expected to increase if a metapopulation dynamics is favored over the coming decades, despite a 1.3% loss rate of forest cover. The monitoring of population size and genetic diversity is highly recommended to validate the trends suggested by the model; this is especially true for D. marsupialis, a species associated with conserved areas that are becoming progressively less abundant. This research provides information on the responses of common mammalian species to environmental changes such as deforestation. [ABSTRACT FROM AUTHOR]

Phyllostomid bats display a variety of social structures and mating systems; the influence of these features on the distribution of genetic diversity within and between bat populations is currently unknown. Based on the mitochondrial DNA D-loop region, we investigated the relationship between genetic structure and social characteristics in four species of phyllostomid bats (Sturnira hondurensis, Artibeus jamaicensis, Carollia sowelli, and Dermanura tolteca) inhabiting Selva El Ocote Biosphere Reserve (REBISO). According to their ecological characteristics, we expected a relatively high genetic diversity and stable populations, as well as a weak genetic structure in S. hondurensis and C. sowelli, and a moderate one in A. jamaicensis and D. tolteca. The demographic history and mismatch distribution were inferred. Besides, we estimated the time elapsed from demographic change (in number of generations). Finally, we calculated standard genetic diversity indicators and determined the genetic structure, haplotype networks, and conducted spatial autocorrelation analyses. Genetic diversity was higher in S. hondurensis, intermediate in C. sowelli, and low in A. jamaicensis and D. tolteca. The neutrality tests indicated population expansion in A. jamaicensis, C. sowelli, and D. tolteca; S. hondurensis showed differentiation between populations with no apparent demographic changes. The extent of genetic differentiation was high in S. hondurensis, intermediate in C. sowelli, weak in A. jamaicensis, and nil in D. tolteca. The spatial autocorrelation revealed genetic structure at certain geographic distances in A. jamaicensis, C. sowelli, and S. hondurensis, while D. tolteca displayed a low structure at the greatest geographic distances. No clear relationship was evident between ecological attributes and genetic structure in the bat species studied, probably due to the slight differences in the ecological characteristics of these species. Further studies should include ecological factors such as resource availability and habitat selection, as well as nuclear markers, to obtain a biparental genetic estimation. This study highlights the need of conduct further research about the relationship of ecological and genetic traits of tropical bats in high-biodiversity reserves. [ABSTRACT FROM AUTHOR]