Epizoochorous dispersal by barbs, hooks, and spines in a lowland moist forest in central French Guiana

An analysis of the flowering plant flora of a lowland moist forest in central French Guiana reveals 25 species with adaptations for epizoochorous dispersal by barbs, hooks, or spines (stick-tights). This represents 1.5% of the flowering plant flora. Stick-tights are represented among the monocotyledons of the flora of central French Guiana by five species of Poaceae. The Fabaceae and Asteraceae, each with six species with stick-tight dispersal, are the richest families of flowering plants in terms of stick-tight dispersal in central French Guiana. This region possesses numerous potential mammal and bird dispersal agents, therefore it is a puzzle why stick-tight dispersal, especially among species of the canopy, is not more frequent.     

Four new species of Calathea (Marantaceae) from French Guiana

Four new species are described: Calathea erecta, C. dilabens, C. granvillei , and C. squarrosa , based on material from French Guiana. Calathea erecta and C. granvillei are known also from the central Amazon Basin. Calathea squarrosa probably also occurs in Surinam. Calathea dilabens is presently known only from French Guiana, but probably occurs in adjacent Brazil and Surinam. A tentative key is provided to the species of Calathea known to occur in French Guiana.     

Intraspecific genetic differentiation of Leporinus friderici (Anostomidae, Pisces) in French Guiana and Brazil: a genetic approach to the refuge theory

A genetic study was carried out on a neotropical fish species to illustrate the refuge theory, whose main principles are summarized. The geographical structure of the anostomid species Leporinus friderici was analysed in French Guiana and Brazil by horizontal starch gel electrophoresis. Fifteen enzymatic systems corresponding to 21 loci were studied, revealing the following particularities: (1) specimens of fish from six independent coastal rivers of French Guiana form two groups geographically situated on either side of the Kourou River; (2) two alleles can serve as geographic markers, Ldh2 ( l30 ) showing an affinity between the populations in eastern French Guiana and Brazil, and Me 1 ( 300 ) being specific to the west.
These observations are probably related to the refuges that were formed in the Quaternary in South America, especially on the Guiana Shield. We consider that the populations of French Guiana are separated into two groups at the boundary between the two migratory flows, one arising in the west from the refuge of the Guiana Shield and the other in the east from a nearby undetermined Amazonian refuge.     

New species of Hiraea (Malpighiaceae) from the Guianas and adjacent Brazil

Four species of Hiraea are described and discussed:H. gracieana andH. morii from Saül, French Guiana,H. longipes from the Oyapock region of French Guiana and Amapá, Brazil, andH. propinqua from French Guiana and Suriname.Hiraea gracieana is illustrated.     

Paullinia lingulata (Sapindaceae), a new species from French Guiana

The new species Paullinia lingulata from French Guiana is described, illustrated, and compared with a vegetatively similar species found in French Guiana.     

Specific epithets of the flowering plants of central French Guiana

The epithets of the flowering plants of central French Guiana are classified into derivation categories. Specific epithets of the flowering plants of central French Guiana refer mostly to shapes (274 species), persons (252), places (212), appearance (146), and size (140). These categories account for 55% of names given to the plants of this flora. The most prolific publishers of names for the flora of central French Guiana are Aublet and Linnaeus, who were respectively the authors of 177 and 110 of the names of species (15% of the total) found in the flora of central French Guiana. Although many of the species names, such as those relating to place and person, are easy to categorize, many others are open to different interpretations. Specific epithets with different orthographies derived from Guiana or Guyana are discussed. In addition, problems in the use of diacritical marks and inconsistencies with spacing between the abbreviations of given names and surnames of authors of plant names are noted.     

Aedes aegypti survival and dengue transmission patterns in French Guiana.

Field survival of Aedes aegypti females is a key parameter for estimating the dengue transmission potential of a mosquito population. The objectives of this study were to explore the dynamics of these survival rates at different times of the year in French Guiana and to analyze the results from the perspective of dengue patterns. The mosquitoes were captured, marked, released, and recaptured during four consecutive days in six houses every month, for three to 24 months, from January 1997 to December 1998. Laboratory experiments showed no effects on female survival but some effect on the survival of males. Females' daily survival in the field varied from 0.525 to 1 but was mostly between 0.8 and 0.95 during the entire year, with a mean value of 0.913. The field survival of Ae. aegypti females in French Guiana was thus in agreement with the likely transmission of dengue and the dengue endemic patterns throughout the year. On the other hand, heavy rainfalls during this time were less favorable to Ae. aegypti survival, which may explain part of the El Ni?o effect on dengue epidemics in French Guiana. The methods and results on Ae. aegypti survival will be implemented in a global dengue surveillance network in French Guiana.     

Black flies (Diptera: Simuliidae) of French Guiana: cytotaxonomy and a preliminary list of species

The objectives of the present study were to broaden the survey of simuliid species in French Guiana and to cytologically analyze the species in the Simulium perflavum species group. Twelve species of Simulium were collected from which S. goeldii, S. quadrifidum, S. trombetense, S. near incrustatum, S. metallicum (s.l.) sp1, S. metallicum (s.l.) sp2 and S. ochraceum (s.l.) are reported for the first time for this region. The only species collected in the S. perflavum group was S. rorotaense; 34 larvae of this species were cytologically analyzed, all of which had the standard sequence. S. metallicum (s.l.), S. ochraceum (s.l.), S. guianense (s.l.) and S. oyapockense (s.l.) are involved with transmission of onchocerciasis in Central and South America, however, in French Guiana these species were not found biting humans during the sampling period. With the few collections made during this study, we increase the number of simulid species known in French Guiana from 6 to 13. It is clear that more simuliid species can be expected to be found when more sampling is done, including collections in other ecoregions in French Guiana.     

Seroprevalence of Trypanosoma cruzi infection in French Guiana

A survey was carried out on 1487 individuals to assess the seroprevalence of Trypanosoma cruzi infection in French Guiana. The overall prevalence of T. cruzi specific IgG was 0.5%. In multivariate analysis, residence in areas where housing is favorable for the presence of triatomine bugs was the only factor associated with the presence of T. cruzi antibodies. These results have implications for public health since blood donors are not routinely screened for T. cruzi infection in French Guiana.     

Phlebotomine sand flies (Diptera: Psychodidae) associated with changing patterns in the transmission of the human cutaneous leishmaniasis in French Guiana

Between March 2000 and December 2001 a survey of the sand flies (Diptera: Phlebotominae) of French Guiana was carried out during 14 nights of captures with CDC light-traps and Malaise traps, and resulted in the collection of 2245 individuals of 38 species. The most abundant species were Lutzomyia (Trichophoromyia) ininii Floch & Abonnenc, Lu.(Psychodopygus) squamiventris maripaensis Floch & Abonnenc, and Lu .(Nyssomyia) flaviscutellata Mangabeira. Half of the collected sand flies females were dissected under field conditions and five species were found harboring Leishmania-like parasites. The Leishmania (Kinetoplastidae: Trypanosomatidae) species were identified by molecular typing, and for the first time Lu. (Nys.) flaviscutellata was found harboring Leishmania (Viannia) guyanensis and Lu. (Tri) ininii harboring unknown Leishmania. The first record for French Guiana of Lu. (Psy.) squamiventris maripaensis harboring L. (V.) naiffi, was also reported. The patterns of diversification of the human cutaneous leishmaniasis transmission in French Guiana are discussed.     

Report on wind dispersal in a lowland moist forest in central French Guiana

An analysis of the flowering plant flora of a lowland moist forest in central French Guiana reveals 298 species with adaptations for wind dispersal. This represents 16.2% of the flowering plant flora and 9.8% of the class Magnoliopsida (dicotyledons). The most diverse wind-dispersed families are the Orchidaceae in the Liliopsida (monocotyledons) with 135 species and the Bignoniaceae in the Magnoliopsida with 37 species. The wind-dispersed species of central French Guiana have evolved either small, dust-like seeds, fruits or seeds with various kinds of wings, fruits or seeds with tufts of hairs, or expanded wing- or parachute-like persistent calyces. Most wind-dispersed species, among the liliopsids, are epiphytes and, among the magnoliopsids, trees or lianas. In central French Guiana, collections of these species with mature diaspores have been gathered most often in October and March, the months with peak wind velocities. In contrast, collections from June and July, when wind velocities are at a minimum, are rare.     

Phylogenetic relationships and biodiversity in Hylids (Anura: Hylidae) from French Guiana

We evaluated two biodiversity criteria, higher taxonomic diversity and phylogenetic diversity in French Guiana. For this, we used a recent assessment of the knowledge accumulated since 30 years of study on the amphibian species currently known in French Guiana. We focused on two well-represented genera, Hyla and Scinax, belonging to the subfamily Hylinae. We used partial sequences of two mitochondrial genes (16S rDNA and 12S rDNA, 813 bp) and two nuclear genes (tyrosinase and 18S rRNA, 1590 bp) covering a total of 2403 bp. According to the high bootstrap support in phylogenetic analysis of the complete dataset, the genus Scinax is a homophyletic clade formed by two species groups (rubra and rostrata) in French Guiana. The genus Hyla was confirmed to be a paraphyletic group formed by two species groups as well (30 chromosomes and the 'gladiator frogs'). We confirmed that these genera should be taxonomically reconsidered. Moreover, at the genus, subfamily and family levels, the use of only morphological characters or only molecular DNA markers would hamper estimations of biodiversity. Thus, we strongly advise the combined use of both morphology and molecular data (nuclear and mitochondrial markers).     

Polymorphic microsatellites for the study of fragmented populations of Pitcairnia geyskesii L. B. Smith (Bromeliaceae), a specific saxicolous species of inselbergs in French Guiana

Pitcairnia geyskesii is a saxicolous bromeliad endemic to the granitic inselbergs of French Guiana and Surinam. Seven polymorphic microsatellite markers were characterized to investigate the polymorphism among individuals sampled on five inselbergs in French Guiana. The total number of alleles per locus varied from four to 14. Mean observed heterozygosities at each microsatellite locus ranged from 0.114 to 0.629. This set of microsatellites offers an efficient tool for more detailed investigations on the genetic structure of fragmented populations living on such a singular and insular habitat within tropical rainforest.     

A survey of adult anophelines in French Guiana: enhanced descriptions of species distribution and biting responses

In French Guiana, Anopheles darlingi is considered the main malaria vector. However, several reports have hypothesized the implication of other anopheline species in malaria transmission for the territory. Data on the ecology of these other potential vectors is rare or even unexplored in French Guiana. The aim of this study was to describe the biting habits of several anopheline species in multiple localities in French Guiana. Six sampling sites yielded 1,083 anopheline adults. Results indicated the presence of An. darlingi in all study locations and it was the only species to be collected inside villages. Other anophelines collected included An. aquasalis, An. braziliensis, An. intermedius, An. mediopunctatus, An. nuneztovari, An. oswaldoi, and An. triannulatus, all of which were associated with open areas and forests. The environment and time, at which biting behavior was recorded, varied for each species. It was noted that An. oswaldoi showed a daytime rhythm in open areas. This study is the first to report on the biting habits of a range of anophelines in French Guiana that may play a role in malaria transmission. This information is vital to fully describe the risk of malaria transmission and thereby design appropriate vector control measures and malaria prevention programs.     

Incrimination of Anopheles (Anopheles) intermedius Peryassú, An. (Nyssorhynchus) nuneztovari Gabaldón, An. (Nys.) oswaldoi Peryassú as natural vectors of Plasmodium falciparum in French Guiana

Anopheles darlingi Root is the major vector of human malaria in the Neotropics and has been considered to be the sole malaria vector in French Guiana. The presence of other potential vectors suggests that malaria may be transmitted by other species under certain conditions. From 2006-2011, all anopheline specimens collected from 11 localities were assayed to determine if the Plasmodium circumsporozoite protein was present. In addition to An. darlingi, we found Anopheles oswaldoi, Anopheles intermedius and Anopheles nuneztovari specimens that were infected with Plasmodium sp. Further investigations on the behaviour and ecology of An. oswaldoi, An. intermedius and An. nuneztovari are necessary to determine their role in malaria transmission in French Guiana.     

Genetic studies in French Guiana populations: Synthesis

Twelve blood group and protein systems from a total of 819 individuals from six tribal groups (Apalaí‐Wayana, Emerillon, Kaliña, Palikur Wayampi, and Wayana) living in French Guiana and Brazil were compared with each other and integrated with previous results from 17 other South Amerindian populations studied for the same genetic markers. Using correspondence analysis, map methodologies, and maximum linkage cluster analysis developed with the UPGMA method, we attempted to establish the genetic position of these tribes among South American Indians. Peripheral positions for the Emerillon and the Palikur were observed. Ethnohistorical data in French Guiana suggest that a strong founder effect for the former and endogamy for the latter could have generated the genetic differentiation of these two ethnic groups. However, when considered in a wider context, all French Guiana Natives cluster together in an intermediate position as compared with 17 other Amerindian groups studied for the comparison. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.     

Isoenzyme differentiation of Aedes aegypti populations in French Guiana

Population genetics of peri-domestic Aedes aegypti (Diptera: Culicidae), vector of dengue and yellow fever, were investigated by gel electrophoresis of 10 enzyme loci in 14 samples of mosquito larvae collected in 1997-1998 from localities separated by distances of 3-275 km in French Guiana. Genetic differentiation between geographical populations was generally high (mean FST = +0.111, P < 10(-5)) even among seven sites <30 km apart (FST = +0.137, P < 0.05), but not positively correlated with distance. Thus, Ae. aegypti comprises a mosaic of genetically differentiated populations in French Guiana. This may be attributed to reinvasion from diverse origins through repeated founder events after this vector species was eliminated during the 1940s to 1960s.     

A new species of Bactris (Palmae) from French Guiana

A new species,Bactris nancibaensis, from French Guiana, is described and illustrated.