Reconciling a Broken Heritage: Developing Mental Health Social Work in Guyana.

Guyana's colonial past has left a trail of economic instability, racial polarization, and physical and mental trauma. Despite the progress made since Guyana's independence in 1966, the remnants of this colonial past continue to shape present-day Guyana. As a result, violence and trauma continue to impact the mental health of the population. This is manifest in endemic problems of domestic violence and racialized social divisions which have created the conditions for rates of suicide which are amongst the highest in the world. The formal mental health provision which exists in Guyana is based primarily on an individualized and largely biomedical model of care. Despite valuable attempts to develop this provision, the difficulty of physically accessing this for some people and the stigma which surround this means that the capacity of this system to address the serious problems which exist is limited. It is also the case that in times of emotional and psychic distress, and in the context of Guyana being a very religious country, many people turn to traditional supernatural healers and remedies for support. In this paper, we discuss what is known as "Obeah", noting that while this is widely practiced, it remains something of a taboo subject in Guyana. We consider the reasons why these practices and beliefs continue to be influential. However, what neither these biomedical or supernatural perceptions of mental health are able to address is the sociogenic nature of Guyana's mental health issues, which we argue emerges out of the historic trauma of Guyana's experience of colonialism and the violence which it engendered. We argue that profound forms of mental distress which exist in Guyana call for an integrative and holistic practice model that contextualizes these problems through a sociogenic lens. Social workers, working collaboratively with other health-related professions, can occupy a critical role in integrating these different conceptions through developing a rights-based model of mental health where the causes of mental ill-health are understood as socially determined.

Continuity of care: The ongoing use of "bush medicine" as a transnational therapeutic health practice in Guyanese immigrant communities.

Using in-depth interviews with Guyanese immigrants in North America this paper argues their therapeutic landscapes are produced transnationally and these transnational therapeutic landscapes impact their ongoing health practices in the country of settlement. The results reveal that the historical use of traditional "bush medicine" provided a resilient response to inaccessible biomedical healthcare in Guyana. However, the continued use of bush medicine in the countries of settlement is not a result of barriers to healthcare. Instead, continued use constitutes a transnational therapeutic health practice that is tied to historical use, perceived efficacy of treatments, and participants' perceptions of Guyana as a therapeutic landscape.

Sorcery and well-being: bodily transformation at Beckeranta.

This paper examines bodily transformation and well-being within the context of a millenarian movement that emerged during the 1840s in the area surrounding Mount Roraima at the periphery of Brazil, Guyana (British Guiana at the time), and Venezuela. The site of this movement was Beckeranta - meaning 'Land of the Whites' - where up to 400 Amerindians were reportedly killed in a quest that is described in its sole historical account as centred around a goal of bodily transformation into white people. In examining this movement, the paper engages with longstanding debates in medical anthropology concerning the body, as well as conversations among Amazonianists concerning the social formation of bodies, and examines sorcery and shamanism as practices that go 'beyond the body'. Notions of bodily transformation in Amazonia, which are often activated by strong emotions, facilitate conceptual expansions of the body in medical anthropology. The paper suggests that bodily transformations tied to sorcery and shamanism are in some contexts, such as at Beckeranta, associated with desires for well-being.Supplemental data for this article is available online at https://doi.org/10.1080/13648470.2020.1807726.

Community owned solutions for fire management in tropical ecosystems: case studies from Indigenous communities of South America.

Fire plays an increasingly significant role in tropical forest and savanna ecosystems, contributing to greenhouse gas emissions and impacting on biodiversity. Emerging research shows the potential role of Indigenous land-use practices for controlling deforestation and reducing CO2 emissions. Analysis of satellite imagery suggests that Indigenous lands have the lowest incidence of wildfires, significantly contributing to maintaining carbon stocks and enhancing biodiversity. Yet acknowledgement of Indigenous peoples' role in fire management and control is limited, and in many cases dismissed, especially in policy-making circles. In this paper, we review existing data on Indigenous fire management and impact, focusing on examples from tropical forest and savanna ecosystems in Venezuela, Brazil and Guyana. We highlight how the complexities of community owned solutions for fire management are being lost as well as undermined by continued efforts on fire suppression and firefighting, and emerging approaches to incorporate Indigenous fire management into market- and incentive-based mechanisms for climate change mitigation. Our aim is to build a case for supporting Indigenous fire practices within all scales of decision-making by strengthening Indigenous knowledge systems to ensure more effective and sustainable fire management.This article is part of the themed issue 'The interaction of fire and mankind'.

A ten-year profile of cancer in Guyana from 2003–2012

OBJECTIVE: Only one cancer report (2000–2004) on Guyana has ever been published. We sought to establish the profile of cancers in Guyana to assist policy-makers indeveloping a comprehensive cancer programme. SUBJECTS AND METHODS: Data from 2003–2012 from the population-based Guyana Cancer Registry were analysed. Frequencies were determined for each cancer by patient demographics and cancer characteristics. Incidence and mortality rates were calculated using Guyana’s resident 2002 population. RESULTS: A total of 6518 incident cancers were recorded:3956 in females and 2561 in males. Mean age of females was 55.4 years, SD 16.4 and males 62.2 years, SD 18.7 (p< 0.0001). Average annual incidence was 86.8 per 100 000 population (females 105.4, males 68.1), age standardized rate was 139.3 per 100 000 population. In females, the leading sites were breast 1074, cervix uteri 1014 and corpus uteri 325; and in males, prostate 865, colo-rectum 206 and lung 157. By ethnicity, 44.4% of cases were in Afro-Guyanese and 38.4% in Indo-Guyanese. Death occurred in 52.3% (45% of females, 65% of males), for an average annual mortality rate of 48 per 100 000 population(females 47.6 and males 43.4). Lifetime risk of developing cancer was one in eight for females and one in 16 for males. CONCLUSION: Cancers placed a significant burden on the Guyanese population during 2003–2012. Females were affected at a younger age than males. Afro-Guyanese were affected more than other ethnic groups. Significant prevention, treatment and control efforts are required to reduce the morbidity and mortality associated with cancers.

The use of Amerindian charm plants in the Guianas.

BACKGROUND: Magical charm plants to ensure good luck in hunting, fishing, agriculture, love and warfare are known among many Amerindians groups in the Guianas. Documented by anthropologists as social and political markers and exchangeable commodities, these charms have received little attention by ethnobotanists, as they are surrounded by secrecy and are difficult to identify. We compared the use of charm species among indigenous groups in the Guianas to see whether similarity in charm species was related to geographical or cultural proximity. We hypothesized that cultivated plants were more widely shared than wild ones and that charms with underground bulbs were more widely used than those without such organs, as vegetatively propagated plants would facilitate transfer of charm knowledge. METHODS: We compiled a list of charm plants from recent fieldwork and supplemented these with information from herbarium collections, historic and recent literature among 11 ethnic groups in the Guianas. To assess similarity in plant use among these groups, we performed a Detrended Component Analysis (DCA) on species level. To see whether cultivated plants or vegetatively propagated species were more widely shared among ethnic groups than wild species or plants without rhizomes, tubers or stem-rooting capacity, we used an independent sample t-test. RESULTS: We recorded 366 charms, representing 145 species. The majority were hunting charms, wild plants, propagated via underground bulbs and grown in villages. Our data suggest that similarity in charm species is associated with geographical proximity and not cultural relatedness. The most widely shared species, used by all Amerindian groups, is Caladium bicolor. The tubers of this plant facilitate easy transport and its natural variability allows for associations with a diversity of game animals. Human selection on shape, size and color of plants through clonal reproduction has ensured the continuity of morphological traits and their correlation with animal features. CONCLUSIONS: Charm plants serve as vehicles for traditional knowledge on animal behavior, tribal warfare and other aspects of oral history and should therefore deserve more scientific and societal attention, especially because there are indications that traditional knowledge on charms is disappearing.

Spontaneous vegetation encroachment upon bauxite residue (red mud) as an indicator and facilitator of in situ remediation processes.

The spontaneous colonization of a bauxite residue (alumina refining tailings) deposit by local vegetation in Linden, Guyana, over 30 years, indicates that natural weathering processes can ameliorate tailings to the extent that it can support vegetation. Samples were collected from vegetated and unvegetated areas to investigate the relationships between bauxite residue properties and vegetation cover. Compared to unvegetated areas, bauxite residue in vegetated areas had lower pH (mean pH 7.9 vs 10.9), lower alkalinity (mean titratable alkalinity 0.4 vs 1.4 mol H(+) kg(-1)), lower electrical conductivity (mean EC 0.3 vs 2.1 mS cm(-1)), lower total Al (mean Al2O3 19.8 vs 25.8% wt) and Na (mean Na2O 0.9 vs 3.7% wt), and less sodalite and calcite. Accumulation of N, NH4(+), and organic C occurred under vegetation, demonstrating the capacity for plants to modify residue to suit their requirements as a soil-like growth medium. Aeolian redistribution of coarse grained tailings appeared to support vegetation establishment by providing a thin zone of enhanced drainage at the surface. Natural pedogenic processes may be supplemented by irrigation, enhanced drainage, and incorporation of sand and organic matter at other tailings deposits to accelerate the remediation process and achieve similar results in a shorter time frame.

Evidence for the involvement of the serotonergic, noradrenergic, and dopaminergic systems in the antidepressant-like action of riparin III obtained from Aniba riparia (Nees) Mez (Lauraceae) in mice.

Previous work has shown that intraperitoneal administration of riparin III (ripIII) reduces immobility time in the forced swimming test (FST), which suggests potential antidepressant activity. As the mechanism of action is not completely understood, this study is aimed at investigating the antidepressant-like action of ripIII. Following intraperitoneal administration of ripIII at doses of 25 and 50 mg/kg, there were decreases in the immobility time in the FST and tail suspension test without accompanying changes in ambulation (data not shown). The pretreatment of mice with sulpiride (50 mg/kg, i.p.), prazosin (1 mg/kg, i.p.), yohimbine (1 mg/kg, i.p.), and p-chlorophenylalanine (PCPA, 100 mg/kg, i.p. for, four consecutive days) significantly prevented the anti-immobility effect of ripIII in the FST. On the other hand, the anti-immobility effect of ripIII (50 mg/kg, v.o.) was not altered by pretreatment of mice with SCH23390 (15 µg/kg, i.p.) Furthermore, ripIII potentiated the sleeping latency and sleeping time of the pentobarbital-induced sleeping time test and also potentiated apomorphine (16 mg/kg, i.p.)-induced hypothermia in mice. In conclusion, the present study provides evidence that the antidepressant-like effect of ripIII is dependent on its interaction with the serotonergic, noradrenergic (α1- and α2- receptors), and dopaminergic (dopamine D2 receptors) systems.

Leptospirosis outbreak following severe flooding: a rapid assessment and mass prophylaxis campaign; Guyana, January-February 2005.

BACKGROUND: Leptospirosis is a zoonosis usually transmitted through contact with water or soil contaminated with urine from infected animals. Severe flooding can put individuals at greater risk for contracting leptospirosis in endemic areas. Rapid testing for the disease and large-scale interventions are necessary to identify and control infection. We describe a leptospirosis outbreak following severe flooding and a mass chemoprophylaxis campaign in Guyana. METHODOLOGY/PRINCIPAL FINDINGS: From January-March 2005, we collected data on suspected leptospirosis hospitalizations and deaths. Laboratory testing included anti-leptospiral dot enzyme immunoassay (DST), immunohistochemistry (IHC) staining, and microscopic agglutination testing (MAT). DST testing was conducted for 105 (44%) of 236 patients; 52 (50%) tested positive. Four (57%) paired serum samples tested by MAT were confirmed leptospirosis. Of 34 total deaths attributed to leptospirosis, postmortem samples from 10 (83%) of 12 patients were positive by IHC. Of 201 patients interviewed, 89% reported direct contact with flood waters. A 3-week doxycycline chemoprophylaxis campaign reached over 280,000 people. CONCLUSIONS: A confirmed leptospirosis outbreak in Guyana occurred after severe flooding, resulting in a massive chemoprophylaxis campaign to try to limit morbidity and mortality.

Implementation of a standardized HIV patient monitoring system in Guyana.

OBJECTIVE: To describe the process used to implement a comprehensive, standardized, and reliable national system for data collection for HIV care and treatment in Guyana; to provide examples of the program-level data resulting from implementation; and to highlight the monitoring benefits for national programs. METHODS: In 2007, Guyana's Ministry of Health and other key stakeholders adapted the World Health Organization's generic HIV care and antiretroviral therapy (ART) patient monitoring guidelines to fit the Guyana context, which included modifying the patient chart, patient registers, and cross-sectional and cohort reports. Following initial training and feedback from clinical staff, a national patient monitoring system (PMS) was finalized, piloted, and implemented at all care and treatment sites. Thereafter, sites received monthly supportive supervisory visits to review data collection and validate reports. RESULTS: Implementation of the PMS enabled analysis of cohort data for patients on ART. After 12 months, 79% of a combined national cohort of all 50 patients who started ART in June 2007 were alive and on first-line ART regimens. After six years, 58% of the first (April 2002) cohort of ART patients in the country were alive and on ART, with only two (8%) patients on second-line regimens. CONCLUSIONS: Implementation of a national PMS for standardized data collection and reporting across multiple clinical sites ultimately provided important and reliable information on utilization of services, patient outcomes, and survival rates on treatment. These data are used at the national level to monitor the efficacy of the HIV care and treatment program. Successful implementation requires early inclusion of all committed stakeholders and a dedicated human resource team to ensure sustainability of the system.

Implementation of a standardized HIV patient monitoring system in Guyana / Establecimiento de un sistema estandarizado de vigilancia de los pacientes infectados por el VIH en Guyana

OBJECTIVE: To describe the process used to implement a comprehensive, standardized, and reliable national system for data collection for HIV care and treatment in Guyana; to provide examples of the program-level data resulting from implementation; and to highlight the monitoring benefits for national programs. METHODS: In 2007, Guyana's Ministry of Health and other key stakeholders adapted the World Health Organization's generic HIV care and antiretroviral therapy (ART) patient monitoring guidelines to fit the Guyana context, which included modifying the patient chart, patient registers, and cross-sectional and cohort reports. Following initial training and feedback from clinical staff, a national patient monitoring system (PMS) was finalized, piloted, and implemented at all care and treatment sites. Thereafter, sites received monthly supportive supervisory visits to review data collection and validate reports. RESULTS: Implementation of the PMS enabled analysis of cohort data for patients on ART. After 12 months, 79 percent of a combined national cohort of all 50 patients who started ART in June 2007 were alive and on first-line ART regimens. After six years, 58 percent of the first (April 2002) cohort of ART patients in the country were alive and on ART, with only two (8 percent) patients on second-line regimens. CONCLUSIONS: Implementation of a national PMS for standardized data collection and reporting across multiple clinical sites ultimately provided important and reliable information on utilization of services, patient outcomes, and survival rates on treatment. These data are used at the national level to monitor the efficacy of the HIV care and treatment program. Successful implementation requires early inclusion of all committed stakeholders and a dedicated human resource team to ensure sustainability of the system.

OBJETIVO: Describir el proceso utilizado con el objeto de poner en práctica un sistema nacional integral, estandarizado y confiable de recopilación de datos sobre la atención y el tratamiento de la infección por el VIH en Guyana; suministrar ejemplos de los datos que se obtuvieron mediante el programa durante la ejecución; y subrayar las ventajas de la vigilancia para los programas nacionales. MÉTODOS: En el 2007, el Ministerio de Salud de Guyana y otros actores claves adaptaron al contexto de Guyana las directrices básicas de la Organización Mundial de la Salud sobre el seguimiento de los pacientes con VIH que reciben atención y tratamiento antirretrovírico; la adaptación implicó modificaciones en el expediente clínico, el registro de los pacientes, los informes transversales y los informes de cohortes. Después de una capacitación inicial y la retroalimentación por parte del personal médico, se finalizó un sistema nacional de seguimiento de los pacientes, que se puso a prueba y se puso en marcha en todos los centros de atención y tratamiento. Posteriormente, se realizaron visitas mensuales de supervisión y apoyo a los centros, con el fin de examinar la recopilación de los datos y validar los informes. RESULTADOS: La ejecución del programa de vigilancia de los pacientes permitió el análisis de los datos de las cohortes de pacientes en tratamiento antirretrovírico. Después de 12 meses, se encontró que 79 por ciento de una cohorte nacional combinada de los 50 pacientes que comenzaron tratamiento antirretrovírico en junio del 2007 estaban vivos y recibían tratamiento con antirretrovíricos de primera línea. Después de seis años, 58 por ciento de la primera cohorte de pacientes tratados con antirretrovíricos en el país (abril del 2002) estaban vivos, continuaban el tratamiento y solo dos pacientes (8 por ciento) recibían medicamentos de segunda línea. CONCLUSIONES: La ejecución de un programa nacional de supervisión de los pacientes con recopilación y notificación estandarizada de los datos en múltiples centros clínicos suministró en último término información importante y confiable sobre la utilización de los servicios, el desenlace clínico de los pacientes y las tasas de supervivencia con el tratamiento. Estos datos se usan a escala nacional con el fin de vigilar la eficacia del programa de atención y tratamiento de la infección por el VIH. La ejecución eficaz del programa exige la participación temprana de todos los actores claves comprometidos y un equipo de recursos humanos dedicado a velar por la sostenibilidad del sistema.

Cytotoxicity screening of endemic plants from Guayana highlands.

A chemical-ecology approach has been used to screen plants growing in Guyana Highlands as an indicator of production of biologically active secondary metabolites. Extracts of leaves from 19 species, most of them endemic in this area, and collected at the top of Roraima Tepui (2,723 m) were screened in vitro at different concentrations for their potential cytotoxic activity against three tumour cell lines: HT29 (colon), A549 (lung) and MDA-MB-231 (breast). MTT (tetrazolium blue) colorimetric assay was employed as cytotoxicity test. Extracts of nine species caused less than 30% growth in at least one cell line. From these species, high cytotoxic activity was detected in Casearia sylvestris var. lingua and Ledotamnus sessiliflorus extracts; medium activity was found in Cyathea sp. Two other species, Cyrilla racemiflora and Heliamphora minor showed lower but significant cytotoxicity. Further cytotoxicity-directed fractionation of these extracts would be advisable to isolate and identify the active principles of these plants.

Disease concepts and treatment by tribal healers of an Amazonian forest culture.

BACKGROUND: The extensive medicinal plant knowledge of Amazonian tribal peoples is widely recognized in the scientific literature and celebrated in popular lore. Despite this broad interest, the ethnomedical systems and knowledge of disease which guide indigenous utilization of botanical diversity for healing remain poorly characterized and understood. No study, to our knowledge, has attempted to directly examine patterns of actual disease recognition and treatment by healers of an Amazonian indigenous culture. METHODS: The establishment of traditional medicine clinics, operated and directed by elder tribal shamans in two remote Trio villages of the Suriname rainforest, presented a unique investigational opportunity. Quantitative analysis of clinic records from both villages permitted examination of diseases treated over a continuous period of four years. Cross-cultural comparative translations were articulated of recorded disease conditions through ethnographic interviews of elder Trio shamans and a comprehensive atlas of indigenous anatomical nomenclature was developed. RESULTS: 20,337 patient visits within the period 2000 to 2004 were analyzed. 75 disease conditions and 127 anatomical terms are presented. Trio concepts of disease and medical practices are broadly examined within the present and historical state of their culture. CONCLUSION: The findings of this investigation support the presence of a comprehensive and highly formalized ethnomedical institution within Trio culture with attendant health policy and conservation implications.

[Importance of a regional observatory of malarial chemoresistance, an emerging public health problem in the Guyanas region]. / Intérêt d'un observatoire régional de la chimiorésistance du paludisme, problème émergent de santé publique dans la région des Guyanes.

A regular implementation of prophylactic and therapeutic decision trees was organized on a consensus basis in Cayenne, French Guiana in 1990, 1995 and 2002. The updated recommendations were based on the knowledge of the in vitro chemosensitivity profiles of the local isolates, mainly coming from big rivers (Maroni and Oyapock, frontiers with Suriname and Brazil, respectively; and more recently Approuague). Most of the patients infected by Plasmodium falciparum were followed by the medical staff of the main hospitals (Cayenne and Saint-Laurent) and of the peripheral health centers in remote areas. Consequently the epidemiological situation and evolution of chemoresistance have been widely observed on a long-term (since 1994) basis in the Maroni region. Yet, we have only partial information coming from the Oyapock valley, even though an important (most of the time) illegal immigration has been developing since the 90s' leading to a notable modification of the epidemiological status of malaria in this eastern region, including a regular increase of P. vivax infections. Presently very little P. vivax chloroquine (and mefloquine) resistance has been identified but this result could lead to a real public health problem in a near future. As such, the National Reference Center on Plasmodium Chemoresistance in the French West Indies and Guiana (CNRCP-AG in French) is a unique observatory of malaria chemoresistance in the Guyanese shield which works with research laboratories of the Institut Pasteur, Paris. This network strategy offers a very attractive perspective for applications of modern tools, including the validation of chemoresistance molecular markers, for malaria control at both medical and public health levels. Some examples related to chloroquine and artemether resistance are given.

Simply not there: the impact of international migration of nurses and midwives--perspectives from Guyana.

The shortage of nurses and midwives across the world and the migratory trends of these scarce professionals--primarily from low-income countries to fill staffing needs in high-income countries--are critical international health care issues. This article reviews some of the demographic, educational, and socioeconomic factors driving this global trend, the impact on health care delivery in low-income countries, and the effect on the implementation of global public health initiatives. Nurses and midwives migrate from low-income nations while concurrently qualified applicants are rejected from educational programs in high-income countries. The impact of migration on the viability of the health care delivery system in Guyana, South America, is presented as an exemplar nation within the broader global context of ethical dilemmas, pressures on educational systems, and the anti- and pro-migration arguments.

Dispensers, obeah and quackery: medical rivalries in post-slavery British Guiana.

This paper examines the ambiguous place of medical assistants-dispensers-in a post-slavery British Caribbean colony, British Guiana, from the end of slavery in the 1830s to the early twentieth century. Although the latter were crucial to the functioning of the colonial medical system, local physicians resented them, complaining about the economic threat they posed and at times condemning them as quacks. These attacks were part of a wider discussion about the composition of the medical profession and the role of medical auxiliaries in colonial society, and to an extent, they echoed debates conducted in other jurisdictions in this period. But in the British Caribbean, this discussion was significantly different. There, long-standing views about obeah-an Afro-Creole medico-religious practice-as a particularly dangerous and uncivilised type of quackery was part of the discursive context. That those participating in this debate included African-descended physicians whose arrival in the medical profession was recent and contested demonstrates the vexed and complex nature of professionalisation in a post-slavery society.

Symbiotic nitrogen fixation in a tropical rainforest: 15N natural abundance measurements supported by experimental isotopic enrichment.

* Leguminous trees are very common in the tropical rainforests of Guyana. Here, species-specific differences in N(2) fixation capability among nodulating legumes growing on different soils and a possible limitation of N(2) fixation by a relatively high nitrogen (N) and low phosphorus (P) availability in the forest were investigated. * Leaves of 17 nodulating species and 17 non-nodulating reference trees were sampled and their delta(15)N values measured. Estimates of N(2) fixation rates were calculated using the (15)N natural abundance method. Pot experiments were conducted on the effect of N and P availability on N(2) fixation using the (15)N-enriched isotope dilution method. * Nine species showed estimates of > 33% leaf N derived from N(2) fixation, while the others had low or undetectable N(2) fixation rates. High N and low P availability reduced N(2) fixation substantially. * The results suggest that a high N and low P availability in the forest limit N(2) fixation. At the forest ecosystem level, N(2) fixation was estimated at c. 6% of total N uptake by the tree community. We conclude that symbiotic N(2) fixation plays an important role in maintaining high amounts of soil available N in undisturbed forest.

["The demon that turned into worms": the translation of public health in the British Caribbean, 1914-1920]. / "O demônio que se transformou em vermes": a tradução da saúde pública no Caribe Britânico, 1914-1920.

The earliest programs of the Rockefeller Foundation's International Health Commission - IHC were pilot projects for the treatment of hookworm disease in the British colonies of British Guiana and Trinidad. These pioneering ventures into international health have often been portrayed as governed by rigid biomedical principles. In contrast to this view, the article emphasizes the degree to which the exigencies of a public health project that sought to make biomedicine intelligible within the medical systems of subject populations combined with the knowledge of local IHC staff members of Indo-Caribbean descent to generate some fascinating experiments in ethno-medical translation. One term in particular "The Demon that Turned into Worms" is focused on to show how these efforts at medical translation may have legitimized and promoted medical pluralism.

The role of thermogenesis in the pollination biology of the Amazon waterlily Victoria amazonica.

BACKGROUND AND AIMS: Several families of tropical plants have thermogenic flowers that show a 2-d protogynous sequence. Most are pollinated by large beetles that remain for the entire period in the flowers, where they compete for mates and feed. Active beetles require high body temperatures that they can achieve endogenously at great energy expense or attain passively and cheaply in a warm environment. Floral heating is therefore hypothesized to be a direct energy reward to endothermic beetles, in addition to its accepted role in enhancing scent production. METHODS: This study measures the pattern of floral heat production (as temperature in 20 flowers and respiration rates in five flowers) in Victoria amazonica at field sites in Guyana and correlates floral temperatures with body temperatures necessary for activity in visiting Cyclocephala hardyi beetles. KEY RESULTS: Thermogenesis occurred in a bimodal pattern, with peaks associated with the arrival and departure of beetles near sunset. Peak CO(2) production rates averaged 2.9 micromol s(-1), equivalent to a heat production of 1.4 W. Heat was generated mainly in the floral chamber on the first evening and by the stamen complex on the second. Mean chamber temperature remained between 29.3 and 34.7 degrees C during the first night, when ambient temperature was 23.5-25.2 degrees C. Beetles actively competed for mates and consumed stylar processes in the floral chamber, where their mean thoracic temperature was 33.2 degrees C. At the lower ambient temperatures outside of the flower, beetles capable of sustained flight had a similar mean temperature of 32.0 degrees C. CONCLUSIONS: Floral heating is not only associated with attraction, but continues throughout the night when beetles are active inside the flower and increases again when they leave. Floral chamber temperatures similar to activity temperatures of actively endothermic beetles imply that thermogenesis is an energy reward.