Taxonomía y sistemática Conceptos taxonómicos, fenología y epifitismo: el caso de Ceratozamia tenuis (Zamiaceae) Taxonomic concepts, phenology and epiphytism: the case of Ceratozamia tenuis (Zamiaceae)
As an evolutionary lineage cycads are rare, and the extinction risk is high for many species. The genus Ceratozamia, one of the most diverse in Mexico, is experiencing drastic reductions of its habitat. Ceratozamia is widely distributed along the Sierra Madre Oriental, a complex mountain range, in a region characterized by high ecological and cultural diversity. Since 1990, various conservation and management strategies have been applied to this taxon in Mexico but evidence for the effectiveness of these measures is lacking. Ceratozamia in the Mexican Sierra Madre Oriental is highly diverse and endemic, offering a model for analysing geographical distribution patterns with ecological niche modelling. It also presents an opportunity for assessing the success of conservation and management strategies that have been implemented in this area. Here, we examined three aspects that are considered fundamental for the development and evaluation of conservation strategies: (1) taxonomy, (2) ecology and (3) sociocultural anthropology. Our findings suggest a pessimistic outlook for the long-term survival of Ceratozamia species in their natural environment, indicating the need to review the current IUCN Cycad Action Plan for the genus. To improve the protection of Ceratozamia and other taxonomic and/or ecological assemblages, we encourage a multidisciplinary approach, with increased collaboration between natural and social scientists.
The taxonomy of Lomechusini Fleming has a complex history. Recent studies have shown that this group is polyphyletic; however, little is known about the evolutionary interrelationships among its constituent genera. The goals of the present study are to infer the phylogenetic relationships of Falagonia Sharp and closely related genera; to define the boundaries of those genera based on synapomorphic characters; and to explore the evolution of myrmecophily within the lineage. The phylogenetic analyses are based exclusively on morphological characters of adults. A total of 36 operational taxonomic units were used for the analysis. The best trees were selected based on maximum parsimony and Bayesian inference. During the parsimony reconstruction, different weighting strategies were used to recover the most robust phylogenetic hypothesis. Although minor differences were observed in the results of the different analyses, the topologies were consistent throughout. Several groups of genera proposed by Seevers (1965), such as the ‘Tetradonia’ and ‘Ecitopora’ groups, were not recovered. Thus, these may represent nonmonophyletic groups that were based on nonsynapomorphic diagnostic characters. Our analyses consistently recovered the genera Asheidium Santiago‐Jiménez, Delgadoidium Santiago‐Jiménez, Falagonia, Newtonidium Santiago‐Jiménez, Pseudofalagonia Santiago‐Jiménez, Sharpidium Santiago‐Jiménez, Tetradonia Wasmann and Thayeridium Santiago‐Jiménez, forming a monophyletic group that we have called the ‘Asheidium complex’. Falagonia mexicana Sharp shows seven autapomorphies, none of which were used to establish the genus. Based on the phylogenetic results, myrmecophily has evolved independently at least three times within the lineage. This study, based on morphological characters, is one of the first approaches towards gaining an understanding of the phylogenetic relationships within the polyphyletic tribe Lomechusini.
As part of efforts to identify native herbivores of Mexican palo verde, Parkinsonia aculeata L. (Leguminosae: Caesalpinioideae), as potential biological control agents against this invasive weed in Australia, ten species of Tortricidae (Lepidoptera) were reared from Guatemala, Mexico, Nicaragua, and Venezuela: Amorbia concavana (Zeller), Platynota rostrana (Walker), Platynota helianthes (Meyrick), Platynota stultana Walsingham (all Tortricinae: Sparganothini), Rudenia leguminana (Busck), Cochylis sp. (both Tortricinae: Cochylini), Ofatulena duodecemstriata (Walsingham), O. luminosa Heinrich, Ofatulena sp. (all Olethreutinae: Grapholitini), and Crocidosema lantana Busck (Olethreutinae: Eucosmini). Significant geographic range extensions are provided for O. duodecemstriata and R. leguminana. These are the first documented records of P. aculeata as a host plant for all but O. luminosa. The four species of Sparganothini are polyphagous; in contrast, the two Cochylini and three Grapholitini likely are specialists on Leguminosae. Ofatulena luminosa is possibly host specific on P. aculeata. Host trials with Rudenia leguminana also provide some evidence of specificity, in contrast to historical rearing records. To examine the possibility that R. leguminana is a complex of species, two data sets of molecular markers were examined: (1) a combined data set of two mitochondrial markers (a 781-basepair region of cytochrome c oxidase I (COI) and a 685-basepair region of cytochrome c oxidase II) and one nuclear marker (a 531-basepair region of the 28S domain 2); and (2) the 650-basepair “barcode” region of COI. Analyses of both data sets strongly suggest that individuals examined in this study belong to more than one species.
Dos nuevas especies de Pharaxonotha Reitter, 1875 son descritas desde México. Ilustraciones y una clave para identificar las especies conocidas de Pharaxonotha del Nuevo Mundo son dadas. El género Ceratozamia Brongn (Zamiaceae) se registra como hospedero de Pharaxonotha mexicana sp. nov. y P. tenuis sp. nov. por primera vez. Los especímenes fueron colectados directamente en los conos de machos y hembras de C. tenuis
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