Isolation of histoplasma capsulatum from the air in the Aguas Buenas Caves,Aguas Buenas,Puerto Rico

White mice were used to isolate H. capsulatum from the air in the Aguas Buenas Caves, Puerto Rico. Based on the infection of mice, the ten test sites yielded positive results for the presence of the fungus. Air currents through this cave are believed to be the most important factor responsible for the even distribution of H. capsulatum. Cultural differences concerning spore concentrations were observed. Age and sex of the exposed mice do not seen to play a role in acquiring histoplasmosis.     

Colonization history and population differentiation of the Honey Bees (Apis mellifera L.) in Puerto Rico

Honey bees (Apis mellifera L.) are the primary commercial pollinators across the world. The subspecies A. m. scutellata originated in Africa and was introduced to the Americas in 1956. For the last 60 years, it hybridized successfully with European subspecies, previous residents in the area. The result of this hybridization was called Africanized honey bee (AHB). AHB has spread since then, arriving to Puerto Rico (PR) in 1994. The honey bee population on the island acquired a mosaic of features from AHB or the European honey bee (EHB). AHB in Puerto Rico shows a major distinctive characteristic, docile behavior, and is called gentle Africanized honey bees (gAHB). We used 917 SNPs to examine the population structure, genetic differentiation, origin, and history of range expansion and colonization of gAHB in PR. We compared gAHB to populations that span the current distribution of A. mellifera worldwide. The gAHB population is shown to be a single population that differs genetically from the examined populations of AHB. Texas and PR groups are the closest genetically. Our results support the hypothesis that the Texas AHB population is the source of gAHB in Puerto Rico.     

Green Iguanas (Iguana iguana) in Puerto Rico: is it time for management?

Iguana iguana is native to Central and South America, and was introduced into Puerto Rico in the 1970s as a result of pet trade. The invasive biology of this reptile has not been studied in Puerto Rico, where its negative effects may threaten local biodiversity. The purposes of this study were to: (1) estimate population densities of I. iguana; (2) describe some aspects of its reproductive biology; and (3) assess its potential impacts. Visual-encounter surveys were performed at Parque Lineal in San Juan and Canal Blasina in Carolina, while nesting activity data were collected at Las Cabezas de San Juan in Fajardo. Densities of I. iguana in Puerto Rico reached a maximum of 223 individuals ha⁻¹, higher than in any known locality in its native range, and showed fluctuations related to seasonality. Our 2008–2009 observations at the nesting sites document that this population of I. iguana is a reproductively successful species, producing more than 100 egg clutches and 2,558 eggs with a 91.4% egg viability. The ability to proliferate in a low predation environment and the absence of good competitors are the major drivers of the population densities observed in Puerto Rico. We found evidence that I. iguana is threatening native biodiversity and impacting infrastructure, agriculture and human safety. Thus, a management program to control the species must soon be developed to prevent this invasive reptile from becoming more widespread and dominant in other localities around the island.     

VARIATION IN LEAFLET MORPHOLOGY AMONG POPULATIONS OF CARIBBEAN CYCADS (ZAMIA)

Caribbean cycads (Zamia L.) are well known for variation in leaflet morphology. Here, I examine the variation in leaflet morphology among five populations of Zamia in Florida. Variables measured were leaflet length and width, leaflet length: width ratio, leaflet surface area, rachis and petiole lengths, number of leaflets per leaf, and total leaf area. In addition to comparisons among the Florida populations, these populations are compared with three previously studied populations in Puerto Rico (Newell, 1986). For the most part, the populations exhibited significant differences in all variables. In spite of the extensive morphological variation in this group of plants, leaflet morphology has long been important in Zamia taxonomy. The Florida populations would be considered by some to be either one, two, or three different species. The Florida and Puerto Rico populations together might be considered as few as one species or as many as five species. Based upon the data presented here, the five Florida populations appear to represent a single species; and the three Puerto Rico populations appear to represent two additional species. Further clarification of the taxonomy of Caribbean Zamia will require additional characters such as cone morphology and protein or DNA patterns.     

Evaluation of the eradication program forAmblyomma variegatum (Acari: Ixodidae) on Puerto Rico

A cooperative effort between the United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, the Agricultural Research Service, and the Department of Agriculture, Commonwealth Government of Puerto Rico has been successful in eardicatingAmblyomma variegatum (Fabricius) from the islands of Puerto Rico and Vieques (an island municipality of Puerto Rico). Application of acaricides to livestock and dogs at 14-day intervals for an 18-month period eliminated foci of tick infestation on 188 farms in four different locations without additional aerial or ground treatment. Reasons for the success and some of the costs associated with the eradication program on Puerto Rico are presented.     

Genetic analysis of a novel invasion of Puerto Rico by an exotic constricting snake

The tropical island Puerto Rico is potentially vulnerable to invasion by some species of exotic snakes; however, until now no established populations had been reported. Here we report and genetically characterize the nascent invasion of Puerto Rico by an exotic constricting snake of the family Boidae (Boa constrictor) using mtDNA and microsatellite data. Over 150 individual B. constrictor have been removed from Mayagüez municipality since May 2011, and our results from the genetic analysis of 32 individuals suggest that this population was recently founded by individuals of one subspecies from a genetic lineage common to zoo and breeding collections, but that the potential propagule pool consists of two subspecies. We also suggest that anthropogenic long-distance dispersal within the island of Puerto Rico may be occurring from the established population, with implications for further establishment across the island. This study represents the first report of the naturalization of an invasive species of boid snake in Puerto Rico and will be important in determining mitigation strategies for this invasion as well as providing a basis for comparison to other on-going studies of invasive snakes.     

Regeneration filters in post-agricultural fields of Puerto Rico and Ecuador

To better understand how rainforest regenerates after agriculture I sampled the seed rain and seed bank, and set out seeds and seedlings, on microsites defined by distance to the forest in fields both in Puerto Rico and Ecuador. I found that (1) total seeds, species richness and life-form richness were twice as great in the Ecuador seed rain compared to Puerto Rico but Puerto Rico seeds were more evenly distributed among species and (2) total seedlings from the seed bank were similar between Puerto Rico and Ecuador, (3) the majority of seeds were lost to predation among all species and study sites, (4) seed disease was absent in P. aduncum and Miconia prasina, and no seeds germinated for Gonzalagunia spicata and P. riparia, (5) in Ecuador pathogenic disease claimed more seeds than germinated for all species, and Solanum ovalifolium was the only species that had seeds germinate but did not lose seeds to disease, (6) also in Ecuador, insect predation was significantly lower in the forest border for P. aduncum, and seed disease was significantly greater at the 10 m micro site for S. ovalifolium, (7) distance has a significant effect on seedling height and basal diameter, (8) losses of leaf area due to herbivory and pathogens were always low and (9) biomass and leaf specific mass were significantly reduced in the border and forest microsites. I conclude that Ecuador fields had more seeds, species, and life-forms than Puerto Rico fields, predation was the most severe post-dispersal seed filter in all fields, seeds that survived predation on Puerto Rico were lost either to disease or germination but to both mechanisms in Ecuador, all three seed mechanisms in Ecuador fields showed distance effects of seedling growth but not survivorship.     

Acaricide susceptibility ofAmblyomma variegatum (Acari: Ixodidae) from Puerto Rico and Guadeloupe

Base-line data on acaricide susceptibility of larvae and of larvae and nymphs of the tropical bont tick,Amblyomma variegatum (Fabricius), from Puerto Rico and Guadeloupe were collected on 14 and six compounds, respectively. Nymphs 7–8 weeks old from Puerto Rico and Guadeloupe, and larvae 3–4 weeks old from Guadeloupe, were exposed for 24 or 48 h to residues of acetone dilutions of technical-grade or commercial formulations of acaricides on disposable glass pipettes. Effectiveness of the acaricides in killing nymphs (lc ₅₀) from Guadeloupe and Puerto Rico ranged from 0.0001% for deltamethrin to 0.269% for malathion. For Puerto Rico, the susceptibility to toxaphene and amitraz, but not to dioxathion, increased with increasing age of nymphs. Nymphs from Guadeloupe were 9.5 times more susceptible to chlorpyrifos than nymphs from Puerto Rico. The susceptibility of larvae from Guadeloupe to acaricides tested ranged fromlc ₅₀ 0.000012% for deltamethrin to 0.0141% for ethion. There was no evidence of development of acaricide resistance in ticks from Guadeloupe or Puerto Rico.     

Two distinct, geographically overlapping lineages of the corallimorpharian Ricordea florida (Cnidaria: Hexacorallia: Ricordeidae)

We examined the genetic variation of the corallimorpharian Ricordea florida; it is distributed throughout the Caribbean region and is heavily harvested for the marine aquarium trade. Eighty-four distinct individuals of R. florida were sequenced from four geographically distant Caribbean locations (Cura?ao, Florida, Guadeloupe, and Puerto Rico). Analysis of the ribosomal nuclear region (ITS1, 5.8S, ITS2) uncovered two geographically partially overlapping genetic lineages in R. florida, probably representing two cryptic species. Lineage 1 was found in Florida and Puerto Rico, and Lineage 2 was found in Florida, Puerto Rico, Guadeloupe, and Cura?ao. Because of the multi-allelic nature of the ITS region, four individuals from Lineage 1 and six from Lineage 2 were cloned to evaluate the levels of hidden intra-individual variability. Pairwise genetic comparisons indicated that the levels of intra-individual and intra-lineage variability (<1%) were approximately an order of magnitude lower than the divergence (~9%) observed between the two lineages. The fishery regulations of the aquarium trade regard R. florida as one species. More refined regulations should take into account the presence of two genetic lineages, and they should be managed separately in order to preserve the long-term evolutionary potential of this corallimorpharian. The discovery of two distinct lineages in R. florida illustrates the importance of evaluating genetic variability in harvested species prior to the implementation of management policies.     

Conservation status assessment of the Sharp‐shinned Hawk,an endangered insular raptor in Puerto Rico

Sharp‐shinned Hawks (Accipiter striatus) are forest raptors that are widely distributed in the Americas. A subspecies endemic to Puerto Rico (A. s. venator) is listed as endangered and restricted to mature and old secondary montane forests and shade coffee plantations. However, recent information about the population status and distribution of Puerto Rican Sharp‐shinned Hawks is lacking. We developed a spatial geographic distribution model for Sharp‐shinned Hawks in Puerto Rico from 33 locations collected during four breeding seasons (2013–2016) using biologically relevant landscape variables (aspect, canopy closure, elevation, rainfall, slope, and terrain roughness). Elevation accounted for 89.8% of the model fit and predicted that the greatest probability of occurrence of Sharp‐shinned Hawks in Puerto Rico (> 60%) was at elevations above 900 m. Based on our model, an estimated 56.1 km² of habitat exists in Puerto Rico with a high probability of occurrence. This total represents ~0.6% of the island's area. Public lands included 43.8% of habitat with high probability of occurrence (24.6 km²), 96% of which was located within four protected areas. Our results suggest that Sharp‐shinned Hawks are rare in Puerto Rico and restricted to the higher elevations of the Cordillera Central. Additional research is needed to identify and address ecological limiting factors, and recovery actions are needed to avoid the extinction of this endemic island raptor.     

SPRING MIGRATION OVER PUERTO RICO AND THE WESTERN ATLANTIC, A RADAR STUDY

Migration over Puerto Rico was recorded by time-lapse filming of the display of a long-range surveillance radar on 40 days and 37 nights in the period 2 March-29 May 1971. Moderate density movements occurred every night; low density movements occurred on most days. Many birds, primarily passerines, took off from Puerto Rico each evening at 20–45 minutes after sunset.
Almost all birds flew to the west, NW or north. Birds were seen approaching from the direction of the Windward Islands and Venezuela, over Puerto Rico, and departing towards the Bahamas and eastern coast of the U.S. Uni- and multivariate analyses showed that the number of birds departing W-N each evening was positively correlated with following winds.
There is less night-to-night variation in the amount of migration at Puerto Rico than in eastern North America. However, this is apparently the result of less variable weather in the tropics, not the result of any lesser degree of meteorological selectivity by the migrants.
The tracks of the birds were correlated with wind direction. Birds moved WNW-NW with NE side winds but NW-NNW with SE following winds. The tracks were rarely exactly downwind. The variance amongst the directions of individual birds at any given time was usually small and not correlated with cloud cover or magnetic disturbances. The estimated headings of the birds varied from day to day in a pattern suggesting adjustment of headings to compensate at least partially for lateral wind drift.
In autumn many birds approach Puerto Rico from the north or even east of north; in spring few birds moved in the opposite directions. This difference in routes takes advantage of prevailing wind patterns.     

Fitness costs of Cry1F resistance in fall armyworm,Spodoptera frugiperda

Transgenic corn, Zea mays L., expressing the Bacillus thuringiensis Berliner (Bt) protein Cry1F has been registered for Spodoptera frugiperda (J. E. Smith) control since 2003 in the USA. Unexpected damage to Cry1F corn was reported in 2006 in Puerto Rico, and Cry1F resistance in S. frugiperda from Puerto Rico was documented. The study of fitness costs associated with insect resistance to Bt insecticidal proteins is important for understanding resistance evolution and for evaluating resistance management practices used to mitigate resistance to transgenic corn. Currently, no studies have addressed the fitness costs associated with Cry1F resistance in S. frugiperda. In this study, susceptible and resistant strains with similar genetic background and their reciprocal crosses were used to estimate Cry1F resistance fitness costs. Comparisons between life‐history traits and population growth rates of homozygous susceptible, heterozygous and homozygous resistant S. frugiperda were used to determine whether the resistance is associated with fitness costs. Major fitness costs were not apparent in either heterozygotes or homozygous resistant insects. However, there was a slight indication of hybrid vigour in the heterozygotes. Additionally, two lines in which the frequency of the resistant alleles was fixed at 0.5 were followed for seven generations, after which the frequency of resistant alleles slightly decreased in both lines. The lack of strong fitness costs associated with Cry1F resistance in S. frugiperda indicates that initial allele frequencies may be higher than expected in field populations and will tend to remain stable in field populations in the absence of selection pressure (e.g. Puerto Rico).     

Sea level,topography and island diversity: phylogeography of the Puerto Rican Red‐eyed Coquí, Eleutherodactylus antillensis

Quaternary climatic oscillations caused changes in sea level that altered the size, number and degree of isolation of islands, particularly in land‐bridge archipelagoes. Elucidating the demographic effects of these oscillations increases our understanding of the role of climate change in shaping evolutionary processes in archipelagoes. The Puerto Rican Bank (PRB) (Puerto Rico and the Eastern Islands, which comprise Vieques, Culebra, the Virgin Islands and associated islets) in the eastern Caribbean Sea periodically coalesced during glaciations and fragmented during interglacial periods of the quaternary. To explore population‐level consequences of sea level changes, we studied the phylogeography of the frog Eleutherodactylus antillensis across the archipelago. We tested hypotheses encompassing vicariance and dispersal narratives by sequencing mtDNA (c. 552 bp) of 285 individuals from 58 localities, and four nuDNA introns (totalling c. 1633 bp) from 173 of these individuals. We found low support for a hypothesis of divergence of the Eastern Islands populations prior to the start of the penultimate interglacial c. 250 kya, and higher support for a hypothesis of colonization of the Eastern Islands from sources in eastern Puerto Rico during the penultimate and last glacial period, when a land bridge united the PRB. The Río Grande de Loíza Basin in eastern Puerto Rico delineates a phylogeographic break. Haplotypes shared between the PRB and St. Croix (an island c. 105 km south‐east of this archipelago) likely represent human‐mediated introductions. Our findings illustrate how varying degrees of connectivity and isolation influence the evolution of tropical island organisms.     

New microsatellite markers for the ectomycorrhizal fungus Pisolithus tinctorius sensu stricto reveal the genetic structure of US and Puerto Rican populations

The ectomycorrhizal fungus Pisolithus tinctorius has been introduced to many areas around the world as a source of inoculum for pine plantations. However, little is known about the genetic structure of fungal populations in their introduced habitats. To study the genetics of exotic P. tinctorius populations, we developed and employed seven new microsatellite markers and compared samples from Puerto Rico (exotic range) and the eastern United States (native range). Bayesian cluster analysis, neighbor joining analysis and F_ST values all strongly separated Puerto Rican populations from North American populations. Consistent with a founder effect, populations from Puerto Rico had reduced allelic richness when compared to samples from the United States. The genetic structure of P. tinctorius populations in Puerto Rico is weak to modest and is not correlated with geographic distance reflecting anthropogenic movement of inoculum with forestry practices.     

Assessing natural infection with Zika virus in the southern house mosquito,Culex quinquefasciatus,during 2016 in Puerto Rico

The epidemic of Zika in the Western hemisphere has led to intense investigations of all species important in the transmission of Zika virus (ZikV), including putative mosquito vectors. Although evidence points to Stegomyia (= Aedes) (Diptera: Culicidae) mosquitoes as the primary vectors in nature among humans, there remains the possibility that other common mosquito species may be implicated in the rapid spread of the virus. Herein, field‐caught Culex quinquefasciatus (Diptera: Culicidae) collected during June 2016 in different neighbourhoods in San Juan, Puerto Rico were examined for the presence of natural infection with ZikV. Stegomyia aegypti (= Aedes aegypti) from the same locations were also analysed. None of the Cx. quinquefasciatus tested showed natural infection for ZikV, whereas S. aegypti tested positive at seven sites. The present results suggest that Cx. quinquefasciatus was not involved in the transmission of ZikV in San Juan, Puerto Rico in 2016.     

A new genus and species of 'giant hutia' (Tainotherium valei) from the Quaternary of Puerto Rico: an extinct arboreal quadruped?

A large incomplete rodent femur from a Quaternary cave deposit near Barahona, Puerto Rico, is established as the holotype of Tainotherium valei , a new extinct genus and species. Although biogeographic and body size similarities suggest that it may be related to the Puerto Rican giant hutia Elasmodontomys , the Antillean large-bodied rodent family Heptaxodontidae is now interpreted as invalid, and it is impossible to assign Tainotherium to a particular caviomorph family in the absence of associated craniodental material. Tainotherium differs from other West Indian species in possessing a large femoral head, a proximally angled femoral neck, a short greater trochanter and a medially positioned lesser trochanter unconnected by an intertrochanteric crest, and a transversely flattened, anteroposteriorly bowed shaft lacking well-defined ridges. These characters are all associated with arboreal life habits in other mammal groups. The Puerto Rican land mammal fauna was dominated by a rodent radiation occupying a wide variety of niches before human arrival in the West Indies, but although arboreality is correlated with increased likelihood of survival in Quaternary mammalian extinction events, all of this fauna is now extinct. It is unlikely that decreasing aridity and the reduction of Puerto Rican savanna-type environments at the end of the Pleistocene contributed to the extinction of the arboreal Tainotherium , and habitat destruction by pre-Columbian Amerindians may instead have been responsible.     

Negotiation of ethnoracial configurations among Puerto Rican Taíno activists

In Puerto Rico, scholarly histories and common knowledge have presumed that the Taíno – the pre-Columbian population of the island – became extinct at some time between the sixteenth and eighteenth centuries. However, various people on the island challenge this assumption by claiming to be Taíno. The public reemergence of Taíno groups in Puerto Rico is highly disputed by scholars, governmental institutions and non-Taíno populations of the region, often on the basis of Puerto Rico’s long-documented history of creolization and state-sponsored ideology of racial blending. Within this context, the case of Taíno indigenous activism in Puerto Rico offers a critical lens through which to consider interactional challenges involved in claiming belonging to a presumably “extinct” ethnoracial category.     

Effects of fern thickets on woodland development on landslides in Puerto Rico

Abstract. Thicket-forming ferns are common colonizers of disturbed habitats in the tropics, but little is known about their ecology. The effects of thickets formed by the fern Dicranopteris pectinata on tree seedlings on five landslides in the Luquillo Experimental Forest in northeastern Puerto Rico were both positive and negative. Soil moisture and total soil N were higher under fern thickets than in adjacent open areas and soil bulk density and soil surface temperatures were lower. Germination of seeds of the tree Cecropia schreberiana was higher for seeds sown under fern thickets than for those sown into adjacent open areas. Tree seedlings of Tabebuia hetero-phylla exhibited a threefold reduction in photosynthesis under ferns, probably resulting from a twelvefold reduction of photosynthetic photon flux density. Growth of Tabebuia seedlings was reduced under ferns but the distribution of seedlings of naturally occurring woody plants was not strongly correlated with the presence of fern thickets. Although fern thickets on low-nutrient landslide soils appear to facilitate germination, they inhibit growth of tree seedlings and may, therefore, delay forest development on landslides in Puerto Rico.     

Riding the perennial gale: working-class Puerto Ricans and the involution of colonial capitalism

Hurricane María devastated Puerto Rico in September 2017, deepening an already dire economic situation and amplifying an ongoing wave of out-migration. In the age of permanent man-made climate change, hurricanes, like extended economic crises, are “big events” produced by the capitalist despoiling of nature and labor, further exposing the dispossessed and displaced to structural violence. A colony of the USA since 1898, perhaps Puerto Rico has now once again “changed forever,” as the popular belief goes in the wake of María. If so, these changes will continually be experienced and enacted differently by subjects unevenly positioned in terms of unequal relationships of power and privilege. I propose an empirically informed research orientation that examines the situation of contemporary working-class Puerto Ricans in terms of their strategic responses to the involution of colonial capitalism. As a dimension of social life, working-classness is not contracting but expanding, in the context of an ongoing “debt crisis” better understood in terms of the self-consumption, or involution, of the modality of colonial capitalism established in Puerto Rico in the 1940s. In this light, strategic actions of working-class Puerto Ricans such as migration, informal labor, and subsistence/domestic production are not evidence of alternate modes of being, but part of the very conditions of working-classness today. I conclude by briefly identifying three areas for future research to flesh out the proposed orientation, focusing in the immediate term on responses to María by working-class communities in the island and the diaspora, in interaction with local and US elites.