Horizontal transmission and recombination of Wolbachia in the butterfly tribe Aeromachini Tutt, 1906 (Lepidoptera: Hesperiidae)

Wolbachia is arguably one of the most ubiquitous heritable symbionts among insects and understanding its transmission dynamics is crucial for understanding why it is so common. While previous research has studied the transmission pathways of Wolbachia in several insect lineages including Lepidoptera, this study takes advantage of data collected from the lepidopteran tribe Aeromachini in an effort to assess patterns of transmission. Twenty-one of the 46 species of Aeromachini species were infected with Wolbachia. Overall, 25% (31/125) of Aeromachini specimens tested were Wolbachia positive. All Wolbachia strains were species specific except for the wJho strain which appeared to be shared by three host species with a sympatric distribution based on a co-phylogenetic comparison between Wolbachia and the Aeromachini species. Two tests of phylogenetic congruence did not find any evidence for cospeciation between Wolbachia strains and their butterfly hosts. The co-phylogenetic comparison, divergence time estimation and Wolbachia recombination analysis revealed that Wolbachia acquisition in Aeromachini appears to have mainly occurred mainly through horizontal transmission rather than codivergence.

Genetic Introgression and Morphological Variation in Naked-Back Bats (Chiroptera: Mormoopidae: Pteronotus Species) along Their Contact Zone in Central America

Two sibling bare-backed bat species (Pteronotus fulvus and P. gymnonotus) have been traditionally differentiated by their size. However, intermediate specimens between the two species have been found in sympatric populations along southern Mexico and it has been suggested that they may be the outcome of a hybridization process between the two species. We used one mitochondrial (COI), three nuclear markers (PRKCL, STAT5A and RAG2) and 13 microsatellites to explore the evolutionary relationships between these two species and elucidate whether the intermediate morphotypes correspond to hybrid individuals. These markers have been analyzed in sympatric and allopatric populations of the two species plus the closely related species Pteronotus davyi. We confirmed the species-level differentiation of the three lineages (P. fulvus, P. davyi and P. gymnonotus), but the phylogenetic hypotheses suggested by the nuclear and mitochondrial markers were discordant. We confirm that the discordance between markers is due to genetic introgression through the mitochondrial capture of P. fulvus in P. gymnonotus populations. Such introgression was found in all P. gymnonotus specimens across its sympatric distribution range (Mexico to Costa Rica) and is related to expansion/retraction species distribution pulses associated with changes in forest distribution during the Quaternary climate cycles. Microsatellite analyses showed contemporary genetic contact between the two sympatric species and 3.0% of the samples studied were identified as hybrids. In conclusion, we found a historical and asymmetric genetic introgression (through mitochondrial capture) of P. fulvus into P. gymnonotus in Mexico and Central America and a limited contemporary gene exchange between the two species. However, no relationship was found between hybridization and the intermediate-sized specimens from southern Mexico, which might likely result from a clinal variation with latitude. These results confirm the need for caution when using forearm size to identify these species in the field and when differentiating them in the laboratory based on mitochondrial DNA alone.

Molecular evidence of the hybrid origin of Cryptocoryne ×purpurea Ridl. nothovar. purpurea (Araceae)

Natural hybridization has been considered a source of taxonomic complexity in Cryptocoryne. A combined study of DNA sequencing data from the internal transcribed spacer (ITS) of nuclear ribosomal DNA and the trnK-matK region of chloroplast DNA was used to identify the parents of Cryptocoryne putative hybrids from Peninsular Malaysia. Based on the intermediate morphology and sympatric distribution area, the plants were tentatively identified as the hybrid Cryptocoryne ×purpurea nothovar. purpurea. The plants were pollen sterile and had long been considered as hybrids, supposedly between two related and co-existing species, C. cordata var. cordata and C. griffithii. The status of C. ×purpurea nothovar. purpurea was independently confirmed by the presence of an additive ITS sequence pattern from these two parental species in hybrid individuals. An analysis of the chloroplast trnK-matK sequences showed that the hybridization is bidirectional with the putative hybrids sharing identical sequences from C. cordata var. cordata and C. griffithii, indicating that both putative parental species had been the maternal parent in different accessions.

Megadiversity in the Ant Genus Melophorus: The M. rufoniger Heterick, Castalanelli and Shattuck Species Group in the Top End of Australia’s Northern Territory

This study contributes to an understanding of megadiversity in the arid-adapted ant genus Melophorus by presenting an integrated genetic, morphological and distributional analysis of diversity within the M. rufoniger group in the 400,000 km2 Top End (northern region) of Australia’s Northern Territory. An earlier study of the Top End’s ant fauna lists eleven species from the M. rufoniger group, but a recent revision of Melophorus described the taxon as a single species occurring throughout most of the Australian mainland. CO1 sequences were obtained for 120 Top End specimens of the M. rufoniger group, along with a specimen from just outside the Top End. We recognize a total of 30 species among the sequenced specimens from the Top End, based on marked CO1 divergence (mean > 9%) in association with morphological differentiation and/or sympatric distribution. The sequenced specimen from just outside the Top End represents an additional species. Our unpublished CO1 data from other specimens from elsewhere in monsoonal Australia indicate that all but two of the 30 sequenced Top End species are endemic to the region, and that such diversity and endemism are similar in both the Kimberley region of far northern Western Australia and in North Queensland. The total number of species in the M. rufoniger group is potentially more than the 93 total species of Melophorus recognized in the recent revision. It has previously been estimated that Melophorus contains at least 1000 species, but our findings suggest that this is a conservative estimate.

Molecular evidence for the hybrid origin of Cryptocoryne ×purpurea Ridl. nothovar. purpurea (Araceae)

Natural hybridization has been considered a source of taxonomic complexity in Cryptocoryne. A combined study of DNA sequencing data from internal transcribed spacer (ITS) of nuclear ribosomal DNA and trnK-matK region of chloroplast DNA was used to identify the parents of Cryptocoryne putative hybrids from Peninsular Malaysia. Based on the morphological intermediary and sympatric distribution, the plants were tentatively identified as the hybrid Cryptocoryne ×purpurea nothovar. purpurea; plants were pollen sterile and had long been considered to be hybrids, possibly between two related and co-existing species, C. cordata var. cordata and C. griffithii. The C. ×purpurea nothovar. purpurea status was independently confirmed by the presence of an additive ITS sequence pattern from these two parental species in hybrid individuals. Analysis of the chloroplast trnK-matK sequences showed that the hybridization is bidirectional with the putative hybrids sharing identical sequences from C. cordata var. cordata and C. griffithii, indicating that both putative parental species had been the maternal parent in different accessions.

A new genus of Rhinebothriidea from species of Psammobatis (Rajiformes: Arhynchobatidae) off Argentina

Two species of a new genus of Rhinebothriidea have been collected from species of Psammobatis Günther along the coast of Argentina. Semiorbiseptum gen. nov. is considered a rhinebothriidean for the presence of facially loculated bothridia borne on stalks and cirrus covered with spinitriches. The genus is unique in the arrangement of loculi and septa on the distal bothridial surface, including semicircular septa in the middle region. Despite the anterior-posterior orientation of bothridia, Semiorbiseptum gen. nov. fits well in the description of the family Rhinebothriidae by lacking a myzorhynchus at the adult stage and postvaginal testes, and by having vitelline follicles that are not interrupted at the level of the ovary. The two new species differ from each other in the number of facial bothridial loculi and in the microthrix pattern on the proximal bothridial surface. Unlike the majority of rhinebothrideans in the marine environment, which show high specificity for their definitive host, Semiorbiseptum mariae sp. nov. was found in two species of Psammobatis, the smallthorn sand skate Psammobatis rudis Günther and shortfin sand skate Psammobatis normani McEachran. These species have a sympatric distribution, similar to the hosts of most rhinebothrideans that parasitize more than one host. On the contrary, Semiorbiseptum alfredoi sp. nov. was found only in P. normani. This study shows that some of the characters previously proposed as possible synapomorphies for the order have interspecific variability or can be equivocally interpreted (e.g. the entrance of the vas deferens into the cirrus sac, bothridial stalk shape).

Use of microhabitat and activity patterns of two lizard species from a seasonal dry forest in northern Colombia

In this work, the microhabitat use and activity patterns of two lizard species with sympatric distribution were evaluated in a dry forest fragment within the department of Sucre, northern Colombia. Data was collected in May, June, September and October of 2017, using the active search method limited by time (7:00 and 19:00 hours). Substrates used, spatial distribution and time of capture were recorded for individuals of the species Loxopholis rugiceps (Cope 1869) and Lepidoblepharis sanctaemartae (Ruthven 1916). Complementarily, environmental and physical parameters were recorded, which allowed us to characterise the microhabitats of the species. A total of 276 lizards were recorded, 177 belonging to the species Loxopholis rugiceps and 99 to Lepidoblepharis sanctaemartae. The results showed similar resource use by the two species for the spatial dimension, with both exploiting different terrestrial elements mainly from the interior forest, followed by the riverbed stream and forest edge. Differences were found in the daily activity patterns between species, with individuals of L. sanctaemartae more frequently recorded in the morning hours and L. rugiceps in the afternoon hours. The activity patterns did not differ by age groups: juveniles and adults. Both species were more frequently found in the litter substrate within the forest, followed by rocks and bare ground. Our results indicate that both species are tolerant to matrix conditions, however, they require internal forest conditions to exploit food resources and refuge.

Two new species of Pristimantis (Anura: Craugastoridae) with notes on the distribution of the genus in northeastern Colombia

We describe two new species of the genus Pristimantis from the western margin of the Eastern Cordillera of Colombia. The species have a sympatric distribution and are found in the humid tropical forests of the lower part of the Tamá National Natural Park (PNN Tamá) and its buffer zone. The new species were described from morphological comparisons and phylogenetic reconstruction from the sequencing of three mitochondrial and two nuclear genes. With these two new species, the number of Pristimantis species known in the department of Norte de Santander has increased to 10. In addition, we included new sequences for the species P. anolirex, P. nicefori, P. mondolfii, and P. yukpa. Our explorations in the last decade indicate that there are probably between five and 10 species that have not been described in the northeastern part of Colombia, especially in areas where the armed conflict has predominated in the last five decades.

Aboveground biomass and seasonal patterns of aboveground net primary productivity in five bamboo species in northern Laos

Aims Accurate estimates of bamboo biomass and net primary productivity (NPP) are required to evaluate the carbon sequestration potential of bamboo forests. However, relevant data that are important for climate change mitigation, have rarely been collected in regions outside of East Asia and India. Information on seasonal patterns of NPP and its components will enable the quantification of factors that influence the carbon balance in bamboo forests. In this study, we quantified the aboveground biomass (AGB) and aboveground NPP of five major bamboo species in northern Laos using monthly data collected over a 12-month period. Methods All live culms in 10, 2 m × 2 m plots (for one monopodial bamboo species: Indosasa sinica) and 30 clumps per species (for four sympodial bamboo species: Bambusa tulda, Cephalostachyum virgatum, Dendrocalamus membranaceus and Gigantochloa sp.) were numbered and measured at breast height. We set 10 or 20 litter traps per species to collect litterfall. Censuses of dead and recruited culms and litterfall collection were performed once per month for 12 months. Important Findings The AGB was highest in I. sinica (59.87 Mg ha−1) and lowest in C. virgatum (11.54 Mg ha−1), and was mostly below the plausible global range for bamboos (32–256 Mg ha−1). The sympatric distribution of multiple bamboo species at the study sites may have suppressed the AGB in four of the five studied species. The aboveground NPP estimates were between 3.43 and 14.25 Mg ha−1 yr−1; those for D. membranaceus (8.20 Mg ha−1 yr−1) and I. sinica (14.25 Mg ha−1 yr−1) were comparable to mean global estimates for temperate evergreen forests (8.78 Mg ha−1 yr−1) and tropical moist forests (10.56 Mg ha−1 yr−1). High culm recruitment rates (15.20–23.39% yr−1) were major contributors to aboveground NPP estimates. Seasonal patterns of aboveground NPP were largely influenced by the phenology of the new culms. In the four sympodial bamboo species, new culms began to emerge following the onset of persistent rainfall, mainly in July and August. However, the sprouting of new culms in the monopodial species I. sinica followed a trend of increasing temperatures, mainly in March and April. Thus, our results indicate that bamboos have considerable potential for sequestering carbon in northern Laos, but that this potential may be affected by climate change.

Comparative studies on population genetic structure of two closely related selfing and outcrossing Zingiber species in Hainan Island

How mating system impacts the genetic diversity of plants has long fascinated and puzzled evolutionary biologists. Numerous studies have shown that self-fertilising plants have less genetic diversity at both the population and species levels than outcrossers. However, the phylogenetic relationships between species and correlated ecological traits have not been accounted for in these previous studies. Here, we conduct a comparative population genetic study of two closely related selfing and outcrossing Zingiber species, with sympatric distribution in Hainan Island, and obtain a result contrary to previous studies. The results indicate that selfing Z. corallinum can maintain high genetic diversity through differentiation intensified by local adaptation in populations across the species’ range. In contrast, outcrossing Z. nudicarpum preserves high genetic diversity through gene exchange by frequent export of pollen within or among populations. Contrary to expectations, the major portion of genetic variation of outcrossing Z. nudicarpum may exist among populations, depending on the dispersal ability of pollen and seed. Our results also reveal that the main factor affecting population structure of selfing Z. corallinum is mountain ranges, followed by a moist climate, while that of outcrossing Z. nudicarpum is likely moisture, but not mountain ranges, due to gene flow via pollen.