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Simple Summary: Urban cockroaches raise health concerns due to their association with pathogens. However, their microbial associates can enhance their physiological and reproductive functions. This article details the bacterial community associated with the oriental cockroach Blatta orientalis Linnaeus, 1758 (Blattodea: Blattidae) using metabarcoding for the first time. We analyze bacterial communities on the exoskeleton and within the gut of this cosmopolitan pest. Specimens were collected from the urban area of Santiago, Chile. DNA extraction and metabarcoding were performed for analysis. Our findings reveal a variety of bacterial lineages, including mutualistic symbionts and pathogenic strains. We examined the metabolic functions of these bacterial communities and their implications for B. orientalis as a pathogen reservoir and vector of zoonosis. Lastly, we consider how the microbial diversity in cockroaches might facilitate their adaptation to human-altered environments. Pest cockroaches share urban habitats with us; their prevalence in urban areas prompts concerns regarding their effect on human health, as synanthropic cockroaches often host pathogenic microorganisms. Nonetheless, microbial associates in these insects can also be related to their biology, contributing to their physiological homeostasis and reproductive success. In this article, we present in detail, for the first time, the bacterial community associated with the oriental cockroach Blatta orientalis, one of the world's five most prominent pest cockroaches. We report the composition of the communities of bacteria found over the exoskeleton and inside the gut of this global pest. We collected B. orientalis in Santiago, Chile's capital city, and the urban nucleus in this country. We conducted DNA extractions and metabarcoding analysis. We found diverse bacterial lineages, including mutualist symbiotic strains, and microorganisms considered pathogenic to humans. We also analyzed the metabolic functions of the bacterial communities identified and discussed the role of B. orientalis as a reservoir and vector of pathogens in urban areas. We discuss to what extent the diversity of functions of the microbial community associated with cockroaches may contribute to emergent properties enabling these insects to inhabit human-modified habitats. [ABSTRACT FROM AUTHOR] more...

In a recent commentary, Nespolo (2003) makes reference to his personal experience as exattendant to the course of evolution imparted by Dr. Humberto Maturana and Dr. Jorge Mpodozis at the Facultad de Ciencias of the Universidad de Chile to construct a negative criticism of Chilean undergraduate teaching of evolution. As ex-attendants of the mentioned course of evolution we have had an experience that is directly comparable to that of Dr. Nespolo. Here we wish to point out our opinion regarding this course, which is markedly different. First, it is a caricature to state that in this course natural selection is taught as being wrong. A serious and critical revision of natural selection, the synthetic theory, and evolutionary ecology is a fundamental part of the course. These and other topics are presented by researchers from those fields, such as Drs. Germán Manríquez and Rodrigo Medel. The scientific contributions of both researchers receive positive comments in Nespolo (2003). more...

Background: Sympatric congeneric plants might share pollinators, or each species might avoid competition by evolving specialized traits that generate partitions in pollinator assemblages. In both cases, pollen limitation (a decrease in the quality and quantity of compatible reproductive pollen) can occur, driving the plant mating system to autogamy as a mechanism of reproductive assurance. We assessed the relationships between pollinator assemblages and mating systems in a group of sympatric congeneric plants. We attempted to answer the following questions: (i) How similar are pollinator assemblages among sympatric cactus species? (ii) Which mating systems do sympatric cactus species use? Methods: We studied sympatric Eriosyce taxa that inhabit a threatened coastal strip in a mediterranean-type ecosystem in central Chile. We performed field observations on four taxa and characterized pollinators during the years 2016 and 2017. We estimated differences in the pollinator assemblages using the Bray–Curtis index. To elucidate the mating systems, we conducted hand-pollination experiments using three treatments: manual cross-pollination, automatic self-pollination, and control (unmanipulated individuals). We tested differences in seed production for statistical significance using Kruskal–Wallis analysis. Results: Eriosyce subgibbosa showed a distinctive pollinator assemblage among the sympatric species that we studied (similarity ranged from 0% to 8%); it was visited by small bees and was the only species that was visited by the giant hummingbird Patagona gigas. Pollinator assemblages were similar between E. chilensis (year 2016 = 4 species; 2017 = 8) and E. chilensis var. albidiflora (2016 = 7; 2017 = 4); however, those of E. curvispina var. mutabilis (2016 = 7; 2017 = 6) were less similar to those of the aforementioned species. E. curvispina var. mutabilis showed the highest interannual variation in its pollinator assemblage (18% similarity). Reproduction in E. subgibbosa largely depends on pollinators, although it showed some degree of autogamy. Autonomous pollination was unfeasible in E. chilensis, which depended on flower visitors for its reproductive success. Both E. chilensis var. albidiflora and E. curvispina var. mutabilis showed some degree of autogamy. Discussion: We observed differences in pollinator assemblages between E. subgibbosa and the remaining Eriosyce taxa, which depend on hymenopterans for pollen transfer. Pollinator assemblages showed considerable interannual variation, especially those of E. subgibbosa (ornithophilous syndrome) and E. curvispina var. mutabilis (melitophilous syndrome). Autogamous reproduction in these taxa may act as a reproductive assurance mechanism when pollinator availability is unpredictable. Our study contributes to improving our understanding of the reproductive systems of ecological interactions between threatened species in a Chilean mediterranean-type ecosystem. [ABSTRACT FROM AUTHOR] more...