Southern Guatemala Research Articles

Postglacial northward expansion and genetic differentiation between migratory and sedentary populations of the broad‐tailed hummingbird (Selasphorus platycercus)

Unlike other migratory hummingbirds in North America, the broad-tailed hummingbird (Selasphorus platycercus) exhibits both long-distance migratory behaviour in the USA and sedentary behaviour in Mexico and Guatemala. We examined the evolution of migration linked to its northward expansion using a multiperspective approach. We analysed variation in morphology, mitochondrial and nuclear DNA, estimated migration rates between migratory and sedentary populations, compared divergence times with the occurrence of Quaternary climate events and constructed species distribution models to predict where migratory and sedentary populations resided during the Last Glacial Maximum (LGM) and Last Interglacial (LIG) events. Our results are consistent with a recent northward population expansion driven by migration from southern sedentary populations. Phylogeographical analyses and population genetics methods revealed that migratory populations in the USA and sedentary populations in Mexico of the platycercus subspecies form one admixed population, and that sedentary populations from southern Mexico and Guatemala (guatemalae) undertook independent evolutionary trajectories. Species distribution modelling revealed that the species is a niche tracker and that the climate conditions associated with modern obligate migrants in the USA were not present during the LIG, which provides indirect evidence for recent migratory behaviour in broad-tailed hummingbirds on the temporal scale of glacial cycles. The finding that platycercus hummingbirds form one genetic population and that suitable habitat for migratory populations was observed in eastern Mexico during the LIG also suggests that the conservation of overwintering sites is crucial for obligate migratory populations currently facing climate change effects.

Roberto Bolaño, Ciudad Juárez, and the Future of Nativism

Roberto Bolano’s novel 2666 is set in several countries in both europe and the americas, and thus might be conceived as belonging to the genre of the cosmopolitan or multinational novel. However, the novel’s longest and most famous section, “the Part about the Crimes,” is set in Ciudad Juarez, Mexico, and tells a story not of multinationalism but rather of indigenism and the local effects of U.S. and Mexican immigration and trade policies, specifically the decades-long record of murders of young indian women from southern Mexico, Guatemala, or points farther south. in this context, the article highlights two painful ironies: first, the irony that, at a time when postcolonial and other critics emphasize post-nationalism, cultural hybridity, and a borderless world, the U.S.-Mexico border is more fortified, and the rhetoric about illegal immigration more intense than at any time in living memory; and second, that the post-9/11 proliferation of nativist rhetoric and factions has occurred precisely at a time when immigration from the south is at its lowest in decades, and when american cities—especially border cities like el Paso—have never been safer (see ).

Land Use Change on Coffee Farms in Southern Guatemala and its Environmental Consequences

Changes in commodity prices, such as the fall in coffee prices from 2000 to 2004, affect land use decisions on farms, and the environmental services they provide. A survey of 50 farms showed a 35% loss in the area under coffee between 2000 and 2004 below 700 m with the majority of this area (64 %) being coffee agroforest systems that included native forest species. Loss of coffee only occurred on large and medium-scale farms; there was no change in area on cooperatives. Coffee productivity declined below 1,100 m altitude for sun and Inga shade coffee, but only below 700 m altitude for agroforest coffee. Coffee productivity was 37-53% lower under agroforests than other systems. Increases in rubber and pasture were related to low altitude large-scale farms, and bananas and timber plantations to mid-altitude farms. Average aboveground carbon stocks for coffee agroforests of 39 t C ha(-1) was similar to rubber plantations, but one-third to one half that of natural forest and timber plantations, respectively. Coffee agroforests had the highest native tree diversity of the productive systems (7-12 species ha(-1)) but lower than natural forest (31 species ha(-1)). Conversion of coffee agroforest to other land uses always led to a reduction in the quality of habitat for native biodiversity, especially avian, but was concentrated among certain farm types. Sustaining coffee agroforests for biodiversity conservation would require targeted interventions such as direct payments or market incentives specifically for biodiversity.

Stelis zootrophionoides (Orchidaceae: Pleurothallidinae), a New Species from Mexico

Background Stelis (Orchidaceae) encompasses approximately 1100 species of epiphytic orchids distributed throughout the Neotropics, with the highest diversity in Andean South America. Sixty-two species were recorded previously in Mexico.MethodsWe formally describe here Stelis zootrophionoides as a new species from Chiapas, Mexico. To determine its systematic position, we conducted a morphological comparison with other members of Pleurothallidinae and a phylogenetic analysis of nucleotide sequences from the plastid matK/trnK and trnL/trnF regions, as well as the nuclear ribosomal ITS region for 52 species of Pleurothallidinae. Sequences of 49 species were downloaded from GenBank and those of three species, including the new taxon, were newly generated for this work. The new species is described and illustrated; notes on its ecological preferences and a comparison with closely related species are presented.ConclusionsThe new species, known only from one location and apparently restricted to the cloud forest in the central highlands of Chiapas, Mexico, is considered a rare species. This small epiphyte is unique among the Mexican species of Stelis by the combination of dark purple flowers with the distal third of the dorsal sepal adhered to the apices of the lateral sepals, which are partially united into a bifid synsepal, leaving two lateral window-like openings, and sagittate labellum. Stelis jalapensis, known from southern Mexico and Guatemala, also has the apices of the sepals adhered to each other, but it is distinguished by its larger flowers with lanceolate, acute dorsal sepal, completely fused lateral sepals (i.e. the synsepal is not bifid), and oblong-elliptic labellum. The phylogenetic analysis shows that S. zootrophionoides is closely related to other Mexican Stelis and corroborates previous suggestions that fused sepal apices have arisen independently in different lineages of Pleurothallidinae.

Profundulus kreiseri, a new species of Profundulidae (Teleostei, Cyprinodontiformes) from northwestern Honduras

A new species of Profundulus, Profundulus kreiseri (Cyprinodontiformes: Profundulidae), is described from the Chamelecón and Ulúa Rivers in the northwestern Honduran highlands. Based on a phylogenetic analysis using cytochrome b and the presence of synapomorphic characters (dark humeral spot, a scaled preorbital region and between 32-34 vertebrae), this new species is placed in the subgenus Profundulus, which also includes Profundulus (Profundulus) oaxacae, Profundulus (Profundulus) punctatus and Profundulus (Profundulus) guatemalensis. Profundulus kreiseri can be distinguished from other members of the subgenus Profundulus by having less than half of its caudal fin densely scaled. Profundulus kreiseri can further be differentiated from Profundulus (Profundulus) oaxacae and Profundulus (Profundulus) punctatus by the absence of rows of dark spots on its flanks. The new species can further be differentiated from Profundulus (Profundulus) guatemalensis by the presence of fewer caudal- and pectoral-fin rays. The new species is distinguished from congeners of the profundulid subgenus Tlaloc (viz., Profundulus (Tlaloc) hildebrandi, Profundulus (Tlaloc) labialis, Profundulus (Tlaloc) candalarius and Profundulus (Tlaloc) portillorum) by having a scaled preorbital region and a dark humeral spot. Profundulus kreiseri and Profundulus portillorum are the only two species of Profundulus that are endemic to the region south of the Motagua River drainage in southern Guatemala and northwestern Honduras.

Phylogenetic relationships and biogeography of Pseudoxiphophorus (Teleostei: Poeciliidae) based on mitochondrial and nuclear genes

Phylogenetic relationships of species of genus Pseudoxiphophorus have been only tackled in detail based on morphology so far. However, phylogenetic evidence based on molecular data is still lacking. In this study, we have used five molecular markers (mitochondrial cytb, 16S, atp6-8, and nuclear actB and S7) to reconstruct a robust, inclusive phylogeny of Pseudoxiphophorus. Our phylogenetic results strongly disagree with the main morphological hypothesis, and indicate different phylogenetic relationships among the recognized species of Pseudoxiphophorus. Pseudoxiphophorus jonesii is recovered as the sister group of all other Pseudoxiphophorus lineages, and this initial splitting may be associated to the extension of the Mexican Neovolcanic Plateau at the Punta del Morro site (event used to calibrate our dating analysis). The branch leading to all other Pseudoxiphophorus separated subsequently into two major groups, one comprising those lineages occurring in southern Mexico and Guatemala–Belize, and another with those lineages that extended further southwards to Honduras and Nicaragua. This event took place during the Pliocene, and is likely associated with periods of inundation of the Polochic–Motagua fault area. The Isthmus of Tehuantepec also appears to have been a strong biogeographic barrier triggering cladogenesis in Pseudoxiphophorus. Heterandria formosa (traditionally placed as sister to Pseudoxiphophorus) is not sharing the most recent common ancestor with Pseudoxiphophorus, and is recovered as more distantly related to them. Furthermore, Pseudoxiphophorus bimaculatus (the most cosmopolitan species) is also recovered as a polyphyletic assemblage that appears to comprise those Pseudoxiphophorus that have not been assigned to the other eight, more localized species. All this suggests that Pseudoxiphophorus needs a major taxonomic revision as a whole in order to incorporate all existing diversity.

Bolbitis moranii (Dryopteridaceae), a new species from southern Guatemala

A new species, Bolbitis moranii, is described and illustrated. It is known only from two localities in the forests of southern Guatemala. It can be distinguished from its congeners in Mesoamerica principally by being an epipetric fern with mostly simple leaves (occasionally ternate) that bear subapical buds and lack prominent lateral secondary veins.

The potential distribution of Grimmia (Grimmiaceae) in Mexico

Hypothetically, the alpine and high elevation moss flora reached central Mexico by migration from northern latitudes following the western mountain ranges. Study of 774 specimens belonging to eighteen species of Grimmia identified four patterns of distribution in Mexico: species restricted to the Neovolcanic Belt, those mainly distributed in the northwestern states, widely distributed taxa, and endemic species. Track analysis showed that the generic distribution indeed followed the western mountains. Modeling was introduced to determine the potential ranges for most Mexican species of Grimmia and review the migration hypothesis. The resulting potential distribution maps using maximum entropy show that several species have discontinuous ranges in the northwestern states. Other taxa are restricted to the Neovolcanic Belt, and still others extend their potential distribution to stations in southern Mexico and Guatemala. Although the original hypothesis proposed that the high altitude moss flora was derived from temperate North America may still be acceptable, the South American distribution of various species indicate that migration may have also proceeded from the south.

First Report ofMegastigmussp. (Hymenoptera: Torymidae) DamagingAbiesspp. (Pinales: Pinaceae) Seeds in Veracruz, Mexico

Abies religiosa (Pinaceae) is native to mountains of central and southern Mexico and western Guatemala, A. hickeli is found only in Mexican states of Veracruz and Oaxaca. Fir forests grow at altitudes of 2000 to 3600 m and account for only 0.16% of the total area of the country. Megastigmus (Hymenoptera: Torymidae) larvae damage up to 57% of the seed production of Cupressaceae, Taxodiaceae and Pinaceae. We examined 8,809 seeds of A. religiosa and A. hickeli and found damage caused by an insect identified as Megastigmus sp. This is the first report of Megastigmus in seeds of Abies religiosa in the state of Veracruz and the first in A. hickeli, considered an endangered species. Data over three years revealed infestations between 8.56% and 10.55%. Our results establish a basis for monitoring Megastigmus population in the zone and for taking preventive management measures in case of increased damage to the seeds.

The Goblin Spider GenusCostarina(Araneae, Oonopidae), Part 1

ABSTRACT The type species of Costarina, C. plena (O. P.-Cambridge), is redescribed, has an unusually broad distribution (extending from southern Mexico to northern Costa Rica), and is sometimes sympatric with a relatively widespread new sibling species, C. subplena. The same region also houses 26 additional new species with much smaller distribution ranges: C. iviei, C. llama, C. oaxaca, C. mixtepec, C. naja, C. sepultura, and C. bochil from southern Mexico, C. belmopan, C. peten, C. macha, C. cahui, C. morales, and C. izabal from Belize and Guatemala, C. cortes, C. cofradia, C. cusuco, C. tela, C. ceiba, C. branstetteri, C. olancho, C. muralla, C. coma, and C. gracias from Honduras, and C. waspuk, C. musun, and C. blanco from Nicaragua. At least 11 of these highly localized, microdistributed species have been taken in sympatry with C. plena. Because C. plena and C. subplena are the only members of the genus that have been collected in western and southern Guatemala, we suspect that this area represents t...

Four new species of the genus Pseudocellus (Arachnida: Ricinulei: Ricinoididae) from Mexico

Four new species of ricinuleids are described: Pseudocellus chankin from caves and surface collections in southern Mexico (Chiapas & Tabasco) and Guatemala (Petén); Pseudocellus jarocho from a single surface collection in Veracruz, México; Pseudocellus oztotl, a troglobitic and troglomorphic species from Cueva de Las Tres Quimeras in the Sierra Negra, Puebla, Mexico; and Pseudocellus platnicki, also troglobitic and troglomorphic, known from a single cave in Coahuila, Mexico. The number of known species in the genus increases to 24, and Mexican species to 14. An identification key for adult males of the species found in Mexico and southern USA is provided.

A delineation of Nuclear Middle America biogeographical provinces based on river basin faunistic similarities

The biogeographical patterns of the obligate freshwater fishes of Nuclear Middle America, a region that expands from southern Guatemala to northern Nicaragua, are described herein. Historically, three broad ichthyological provinces have been assigned to Nuclear Middle America: the Usumacinta, and the San Juan in the Atlantic slope and the Chiapas-Nicaraguense in the Pacific slope. With the use of correspondence analysis and unweighted pair group method with arithmetic mean cluster analysis of a presence/absence matrix of 76 obligate freshwater fishes, we identified four ichthyological provinces in Nuclear Middle America: (1) the Honduras and Guatemala Caribbean Highlands Province, (2) the Honduras and Nicaragua Mosquitia Province, (3) the Chiapas-El Salvador-Nacaome Province, and (4) the Choluteca and Nicaragua Pacific Province. Differences between provinces in species composition and species turnover between provinces were tested by analysis of similarity, the calculation of beta-diversity indices and an indicator species analysis. We then further characterized each province by identifying the number of endemics and classifying species according to their salinity tolerance. The most striking patterns of Nuclear Middle America freshwater fish distribution are its paucity of primary freshwater fishes and limited numbers of endemics. The four ichthyological provinces are distinct as indicated by the ANOSIM and beta-diversity analysis, although one province showed low beta-diversity values. These results suggest that, despite of the active geological history that characterized the region, there has been limited isolation of species in any given province, and historical drainage connectivity has been high.

Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis

Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked to earlier declines and extinctions. We describe a noninvasive PCR sampling technique that detects Bd in formalin-preserved museum specimens. We detected Bd by PCR in 83-90% (n = 38) of samples that were identified as positive by histology. We examined specimens collected before, during, and after major amphibian decline events at established study sites in southern Mexico, Guatemala, and Costa Rica. A pattern of Bd emergence coincident with decline at these localities is revealed-the absence of Bd over multiple years at all localities followed by the concurrent emergence of Bd in various species at each locality during a period of population decline. The geographical and chronological emergence of Bd at these localities also indicates a southbound spread from southern Mexico in the early 1970s to western Guatemala in the 1980s/1990s and to Monteverde, Costa Rica by 1987. We find evidence of a historical "Bd epidemic wave" that began in Mexico and subsequently spread to Central America. We describe a technique that can be used to screen museum specimens from other amphibian decline sites around the world.

Genetic diversity of the mangrove-associated alga Bostrychia radicans/Bostrychia moritziana (Ceramiales, Rhodophyta) from southern Central America

SUMMARY Previous studies suggested that the biodiversity of the mangrove-associated Bostrychia radicans/Bostrychia moritziana species complex on the Pacific coast of Central America, based on genetic and reproductive data, were low compared with similar areas on the Atlantic coast. Evolutionary scenarios were proposed based on either a recent introduction to the Pacific, or a more uniform environment leading to genetically connected populations and low differentiation between populations. We sampled more extensively in southern Mexico, Guatemala and El Salvador and sequenced the samples for the RuBisCo spacer. Our results show that genetic diversity is high in these populations. Many haplotypes retrieved are also found in the Atlantic Ocean (USA, Brazil), an observation not made before. Data suggest that populations are highly differentiated with little evidence of isolation-by-distance. The population at La Puntilla, El Salvador is highly differentiated from other populations. Data also suggest that diversity is reduced in a northerly direction, with only one haplotype, unique to Pacific Central America, found north of Chiapas, Mexico. This could be due to northern expansion of this unique genotype as sea surface temperatures ameliorated following the last glacial maximum. Our data do not support the previous proposition of low diversity in the east central Pacific and suggest that much of the Pacific Central America diversity is from before the closure of the Isthmus of Panama.

The growth and erosion of cinder cones in Guatemala and El Salvador: Models and statistics

Morphologic data for 147 cinder cones in southern Guatemala and western El Salvador are compared with data from the San Francisco volcanic field, Arizona (USA), Cima volcanic field, California (USA), Michoácan–Guanajuato volcanic field, Mexico, and the Lamongan volcanic field, East Java. The Guatemala cones have an average height of 110 +/− 50 m, an average basal diameter of 660 +/− 230 m and an average top diameter of 180 +/− 150 m. The general morphology of these cones can be described by their average cone angle of slope (24 +/− 7), average height-to-radius ratio (0.33 +/− 0.09) and their flatness (0.24 +/− 0.18). Although the mean values for the Guatemalan cones are similar to those for other volcanic fields (e.g., San Francisco volcanic field, Arizona; Cima volcanic field, California; Michoácan–Guanajuato volcanic field, Mexico; and Lamongan volcanic field, East Java), the range of morphologies encompasses almost all of those observed worldwide for cinder cones. Three new 40Ar/ 39Ar age dates are combined with 19 previously published dates for cones in Guatemala and El Salvador. There is no indication that the morphologies of these cones have changed over the last 500–1000 ka. Furthermore, a re-analysis of published data for other volcanic fields suggests that only in the Cima volcanic field (of those studied) is there clear evidence of degradation with age. Preliminary results of a numerical model of cinder cone growth are used to show that the range of morphologies observed in the Guatemalan cinder cones could all be primary, that is, due to processes occurring at the time of eruption.

Two new species of shrews (Soricidae) from the western highlands of Guatemala

The broad-clawed shrews (Soricomorpha: Soricidae: Cryptotis) encompass a clade of 5 species—Cryptotis alticolus (Merriam), C. goldmani (Merriam), C. goodwini Jackson, C. griseoventris Jackson, and C. peregrinus (Merriam)—that is known collectively as the Cryptotis goldmani group and is characterized by broadened forefeet, elongated and broadened fore claws, and broadened humeri. These shrews are distributed in highland regions from central Mexico to Honduras. Two broad-clawed shrews, C. goodwini and C. griseoventris, occur in southern Mexico and Guatemala and are presumed sister species whose primary distinguishing feature is the larger size of C. goodwini. In an investigation of variation within and between these 2 species, I studied characteristics of the postcranial skeleton. Statistical analyses of a variety of character suites indicate that the forelimb morphology in this group exhibits less intraspecific variation and greater interspecific variation than cranio-mandibular morphology, although most skull characters support groupings based on forelimb characters. Together, these characters define 4 distinct groups among the specimens examined. C. griseoventris is restricted to the northern highlands of Chiapas, Mexico, and C. goodwini occurs in the southern highlands of Chiapas and Guatemala. Herein, I describe 2 new species of broad-clawed shrews from the Sierra de los Cuchumatanes, Guatemala.

Spline models of contemporary, 2030, 2060 and 2090 climates for Mexico and their use in understanding climate-change impacts on the vegetation

Spatial climate models were developed for Mexico and its periphery (southern USA, Cuba, Belize and Guatemala) for monthly normals (1961–1990) of average, maximum and minimum temperature and precipitation using thin plate smoothing splines of ANUSPLIN software on ca. 3,800 observations. The fit of the model was generally good: the signal was considerably less than one-half of the number of observations, and reasonable standard errors for the surfaces would be less than 1°C for temperature and 10–15% for precipitation. Monthly normals were updated for three time periods according to three General Circulation Models and three emission scenarios. On average, mean annual temperature would increase 1.5°C by year 2030, 2.3°C by year 2060 and 3.7°C by year 2090; annual precipitation would decrease −6.7% by year 2030, −9.0% by year 2060 and −18.2% by year 2090. By converting monthly means into a series of variables relevant to biology (e. g., degree-days > 5°C, aridity index), the models are directly suited for inferring plant–climate relationships and, therefore, in assessing impact of and developing programs for accommodating global warming. Programs are outlined for (a) assisting migration of four commercially important species of pine distributed in altitudinal sequence in Michoacan State (b) developing conservation programs in the floristically diverse Tehuacan Valley, and (c) perpetuating Pinus chiapensis, a threatened endemic. Climate surfaces, point or gridded climatic estimates and maps are available at http://forest.moscowfsl.wsu.edu/climate/.

A GPS and modelling study of deformation in northern Central America

SUMMARY We use GPS measurements at 37 stations in Honduras and El Salvador to describe active deformation of the western end of the Caribbean Plate between the Motagua fault and Central American volcanic arc. All GPS sites located in eastern Honduras move with the Caribbean Plate, in accord with geologic evidence for an absence of neotectonic deformation in this region. Relative to the Caribbean Plate, the other stations in the study area move west to west–northwest at rates that increase gradually from 3.3 ± 0.6 mm yr −1 in central Honduras to 4.1 ± 0.6 mm yr −1 in western Honduras to as high as 11–12 mm yr −1 in southern Guatemala. The site motions are consistent with slow westward extension that has been inferred by previous authors from the north-striking grabens and earthquake focal mechanisms in this region. We examine the factors that influence the regional deformation by comparing the new GPS velocity field to velocity fields predicted by finite element models (FEMs) that incorporate the regional plate boundary faults and known plate motions. Our modelling suggests that the obliquely convergent (∼20 ◦ ) direction of Caribbean–North American Plate motion relative to the Motagua fault west of 90 ◦ W impedes the ENE-directed motion of the Caribbean Plate in southern Guatemala, giving rise to extension in southern Guatemala and western Honduras. The FEM predictions agree even better with the measured velocities if the plate motion west of the Central American volcanic arc is forced to occur over a broad zone rather than along a single throughgoing plate boundary fault. Our analysis confirms key predictions of a previous numerical model for deformation in this region, and also indicates that the curvature of the Motagua fault causes significant along-strike changes in the orientations of the principal strainrate axes in the fault borderlands, in accord with earthquake focal mechanisms and conclusions reached in a recent synthesis of the structural and morphologic data from Honduras. Poor fits of our preferred models to the velocities of GPS sites near the Gulf of Fonseca may be an artefact of the still-short GPS time-series in this region or the simplifying assumptions of our FEMs.

Intraspecific variation in the stingless beeMelipona beecheiiassessed with PCR-RFLP of the ITS1 ribosomal DNA

In previous works, significant variation in morphometric and molecular characteristics was detected among populations of M. beecheii. Here RFLP tests of the internal transcribed spacer 1 of the ribosomal gene were performed to confirm those results and to evaluate the intraspecific variability within the species. The complete ITS1 region and the flanking regions showed length variation (1720 to 1670) and also three different restriction patterns that allowed differentiation of three groups of colonies with different geographic distribution. Mexican colonies from Yucatan, Campeche and Chiapas, together with one colony from northern Guatemala formed one group, a second was composed of colonies from southern Guatemala, El Salvador and Costa Rica and a third one corresponded to one colony from San Marcos (Guatemala but close to the Mexican border). Such test could be used to characterize locally adapted ecotypes subject to conservation efforts.

Two Distinct Triatoma dimidiata (Latreille, 1811) Taxa Are Found in Sympatry in Guatemala and Mexico

Approximately 10 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease, which remains the most serious parasitic disease in the Americas. Most people are infected via triatomine vectors. Transmission has been largely halted in South America in areas with predominantly domestic vectors. However, one of the main Chagas vectors in Mesoamerica, Triatoma dimidiata, poses special challenges to control due to its diversity across its large geographic range (from Mexico into northern South America), and peridomestic and sylvatic populations that repopulate houses following pesticide treatment. Recent evidence suggests T. dimidiata may be a complex of species, perhaps including cryptic species; taxonomic ambiguity which confounds control. The nuclear sequence of the internal transcribed spacer 2 (ITS2) of the ribosomal DNA and the mitochondrial cytochrome b (mt cyt b) gene were used to analyze the taxonomy of T. dimidiata from southern Mexico throughout Central America. ITS2 sequence divides T. dimidiata into four taxa. The first three are found mostly localized to specific geographic regions with some overlap: (1) southern Mexico and Guatemala (Group 2); (2) Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (Group 1A); (3) and Panama (Group 1B). We extend ITS2 Group 1A south into Costa Rica, Group 2 into southern Guatemala and show the first information on isolates in Belize, identifying Groups 2 and 3 in that country. The fourth group (Group 3), a potential cryptic species, is dispersed across parts of Mexico, Guatemala, and Belize. We show it exists in sympatry with other groups in Peten, Guatemala, and Yucatan, Mexico. Mitochondrial cyt b data supports this putative cryptic species in sympatry with others. However, unlike the clear distinction of the remaining groups by ITS2, the remaining groups are not separated by mt cyt b. This work contributes to an understanding of the taxonomy and population subdivision of T. dimidiata, essential for designing effective control strategies.