Carmen Pozo

LAND CHANGE IN THE SOUTHERN YUCATÁN AND CALAKMUL BIOSPHERE RESERVE: EFFECTS ON HABITAT AND BIODIVERSITY

The southern Yucatán contains the largest expanse of seasonal tropical forests remaining in Mexico, forming an ecocline between the drier north of the peninsula and the humid Petén, Guatemala. The Calakmul Biosphere Reserve resides in the center of this region as part of the Mesoamerican Biological Corridor. The reserves functions are examined in regard to land changes throughout the region, generated over the last 40 years by increasing settlement and the expansion and intensification of agriculture. These changes are documented from 1987/1988 to 2000, and their implications regarding the capacity of the reserve to protect the ecocline, forest habitats, and butterfly diversity are addressed. The results indicate that the current landscape matrix serves the biotic diversity of the reserve, with several looming caveats involving the loss of humid forests and the interruption of biota flow across the ecocline, and the amount and proximity of older forest patches beyond the reserve. The highly dynamic land cover changes underway in this economic frontier warrant an adaptive management approach that monitors the major changes underway in mature forest types, while the paucity of systematic ecological and environment-development studies is rectified in order to inform policy and practice.

Beyond the Colours: Discovering Hidden Diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA Barcoding

Background Recent studies have demonstrated the utility of DNA barcoding in the discovery of overlooked species and in the connection of immature and adult stages. In this study, we use DNA barcoding to examine diversity patterns in 121 species of Nymphalidae from the Yucatan Peninsula in Mexico. Our results suggest the presence of cryptic species in 8 of these 121 taxa. As well, the reference database derived from the analysis of adult specimens allowed the identification of nymphalid caterpillars providing new details on host plant use. Methodology/Principal Findings We gathered DNA barcode sequences from 857 adult Nymphalidae representing 121 different species. This total includes four species (Adelpha iphiclus, Adelpha malea, Hamadryas iphtime and Taygetis laches) that were initially overlooked because of their close morphological similarity to other species. The barcode results showed that each of the 121 species possessed a diagnostic array of barcode sequences. In addition, there was evidence of cryptic taxa; seven species included two barcode clusters showing more than 2% sequence divergence while one species included three clusters. All 71 nymphalid caterpillars were identified to a species level by their sequence congruence to adult sequences. These caterpillars represented 16 species, and included Hamadryas julitta, an endemic species from the Yucatan Peninsula whose larval stages and host plant (Dalechampia schottii, also endemic to the Yucatan Peninsula) were previously unknown. Conclusions/Significance This investigation has revealed overlooked species in a well-studied museum collection of nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization. The utility of barcoding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyperdiverse tropical insect assemblages.

Seasonality and phenology of the butterflies (Lepidoptera : Papilionoidea and Hesperioidea) of Mexico's Calakmul Region

Abstract The phenology of butterflies was analyzed in the Calakmul Region (CR) in the state of Campeche, México, over the course of 3 years. Altogether, 60,662 individuals were recorded, consisting of 359 species in 207 genera, 18 subfamilies, 5 families, and 2 superfamilies. Greatest species diversity was recorded during Oct and Nov. Monthly fluctuation in diversity was defined by rare species. Hesperiidae (135 species) and Nymphalidae (111 species) were the most diverse families, and showed the greatest variation with respect to distribution of species richness throughout the year. Papilionidae showed the greatest species richness during the dry season. Pieridae, Nymphalidae, and Lycaenidae showed peaks of greatest species richness and relative abundance during the rainy season. Results were compared to faunal studies of the Sierra de Atoyac de Álvarez, in the state of Guerrero, and of the Sierra de Manantlán, in Jalisco and Colima. Important similarities were observed among phenological patterns in the butterfly fauna of the 3 regions, especially between CR and Manantlán. The phenology of species with greater relative abundance was analyzed in relation to wingspan as a parameter of adult size. The small and medium-sized groups, taken together, showed variations in species richness. An analysis of species seasonality was conducted with NMDS, ANOSIM and SIMPER, in the program PRIMER 4.0. Differences among the composition of butterfly communities with respect to the seasons were found.

Distribution Patterns of the American Species of the Freshwater Genus Eucyclops (Copepoda: Cyclopoida)

ABSTRACT Based on the superposition of 19 individual tracks of American species of the freshwater copepod genus Eucyclops, two generalized tracks were found. The Western Amazonian track (southern Peru, eastern Brazil, and central Colombia) corresponding to the Amazonian subregion and the South American Transition Zone, and the Mesoamerican-Northwestern South American track (central Colombia, Central America, and northeastern Mexico) corresponding to the Neotropical region, the Mexican Transition Zone, and the Nearctic region. One node was found in Colombia, an area where both generalized tracks intersect. The distributional patterns of Eucyclops apparently involve two cenocrons: one Holarctic, and another Paleotropical. The Western Amazonian generalized track can be correlated with the existence of rivers that function either as barriers or dispersal passageways, the uplift of the Andes, and the presence of the Miocene “Pebas lake/wetland system.” The Mesoamerican-Northwestern South American generalized track can be associated with climate changes resulting from the uplift of North American mountain ranges, the presence of marine barriers (Isthmus of Tehuantepec and Panama) and the uplift of mountains in southern Mexico and Central America. The closing of the marine barrier represented by the Isthmus of Panama seems to have been a key event in the northward and southward dispersal of Eucyclops in the Americas.

Panbiogeography of the Yucatan Peninsula Based on Charaxinae (Lepidoptera: Nymphalidae)

ABSTRACT We have studied the origin of the Charaxinae lepidopteran fauna of the Yucatan Peninsula in a panbiogeographical analysis. The expectation was that this biota had a single origin (one generalized track) from Central America. A database was generated with worldwide distributional records of Charaxinae. The panbiogeographical analysis used the program Trazos2004, an extension for Arc View. A total of 22,124 records and 304 species were obtained, and 226 individual tracks were generated. Seventeen generalized tracks were obtained for the Americas; 2 of these penetrate into the Yucatan Peninsula. We conclude that the origin of the Yucatec Charaxinae fauna is tropical, following in America the Neotropical pattern, the so-called Mexican biogeographic “Y”. This fauna originates from 2 putative Mesoamerican invasions: an older one (perhaps Miocene), that penetrated across the “Sierrita de Ticul” (a low mountain range); the other one more recent (Pliocene), which invaded along the Caribbean coast.

Updating Genomic Data of Lepidoptera

Among the insects, lepidopterans form the second most diverse group, with over 155,000 described species. Research on Lepidoptera has a long tradition in several fields, including taxonomy, phylogeny, ecology, population genetics, evolutionary biology, speciation, physiology, development and gene regulation, host–plant and insect–parasite interactions, and, in recent decades, genomics. These studies and genomic resources for them are widely distributed and often widespread in various databases. In this chapter, we analyze the state of the art for genomic resources for Lepidoptera in GenBank for the following genes: elongation factor-1α, wingless, cytochrome c oxidase I, ribosomal DNA and RNA, and in general a number of other protein and enzyme entries; complete mitochondrial genomes; complete nuclear genomes; and published work on barcode methodology. This information will help researchers find gaps in the available resources and direct research efforts in these areas.