An affordable apparatus for fine-controlled emulation of buzzing frequencies of bees for the testing hypothesis in buzz interactions.

The buzzing foraging behavior of female bees for pollen harvesting called the attention of early pollination biologists. Flower types that demand this buzzing behavior comprise about 20,000 species of different and phylogenetically unrelated plant taxa, suggesting that it had independently evolved many times among the flowering plants. Between the late 1970s and early 1980s, theoretical papers had modeled the energetics of buzz pollination, but, up to this moment, no hypothesis was experimentally tested concerning the theoretical basis of the energetics of buzz pollination. We present a cost-effective and simple apparatus, including a digital and highly accurate frequency generator, and a device for the transference of buzz-frequency energy to the receptive floral unity. The receptive floral unities may comprise the entire or partial androecium, or the tubular corolla, or, in some cases, the whole flower. This apparatus can be easily used in both laboratory and field conditions of research, as natural air currents are avoided, and the response of pollen liberation can be quantitatively measured by pollen grain counts that can be captured by adhesion in slide poured with an isosmotic lactate-glycerol media. The maximum displacement of the hardwire beam/claw system was 0.1170 ± 0.0006 mm @ 150 Hz; 0.021 ± 0.003 mm @ 250 Hz; 0.010 ± 0.001 mm @ 350 Hz; 0.0058 ± 0.0001 mm @ 450 Hz; and 0.0082 ± 0.0005 mm @ 550 Hz. Hypothesis contrasting frequency emission and pollen liberation measured as pollen grain counts may be tested in a species flower type by simple linear regression if pollen counts are normally distributed, or ordinal logistic regression, with non-normal counts. The comparison among different flower-type requirements can be tested through appropriate statistical methods for both normally and non-normally distributed pollen grain counts.

Long-term regeneration of a tropical plant community after sand mining.

Sandy coastal plant communities in tropical regions have been historically under strong anthropic pressure. In Brazil, these systems shelter communities with highly plastic plant species. However, the potential of these systems to regenerate without human assistance after disturbances has hardly been examined. We determined the natural regeneration of a coastal sandy plain vegetation (restinga) in Brazil, 16 years after the end of sand removal. We inventoried 38 plots: 20 within a sand-mined site and 18 in an adjacent undisturbed site. We expected lower diversity values in the sand-mined site compared to the undisturbed site, but similar species composition between the two sites due to the spatial proximity of the two sites and the high plasticity of restinga species. Species were ranked using abundance and importance value index in both sites, and comparisons were performed using Rényi entropy profiles, rarefaction curves, principal component analysis, and redundancy analysis. Species composition and dominant species differed markedly between the two sites. Bromeliads and Clusia hilariana, well-known nurse plants, dominated the undisturbed site but were almost absent in the regenerating site. Species richness did not differ between both sites, but diversity was higher in the undisturbed site. Within-site composition differences in the mined area were associated with field characteristics. Interestingly, species classified as subordinate or rare in the undisturbed site became dominants in the regenerating site. These newer dominants in the sand-mined site are not those known as nurse plants in other restingas, thus yielding strong implications for restoration.

Dendranthema grandiflorum, a hybrid ornamental plant, is a source of larvicidal compounds against Aedes aegypti larvae

Abstract In hybrid cultivated form, Dendranthema grandiflorum (Ramat.) Kitam., Asteraceae, flowers (Chrysanthemum morifolium Ramat.) were utilized in the production of extracts, which were analyzed for larvicidal activity against Aedes aegypti third instar larvae. Methanol and dichloromethane extracts showed LC50 values of 5.02 and 5.93 ppm, respectively. Using GC–MS, phytochemical analyses of the dichloromethane extract showed the presence of triterpenoids and fatty acids, while flavonoids and caffeoylquinic acids were shown to occur in the methanol extract by ESI Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI-FT-ICR-MS). Triterpenoids and fatty acids are well known insecticidal compounds. From this study, it can be concluded that D. grandiflorum grown for floriculture, as an agribusiness, can have additional applications as raw material for the production of insecticidal products.

Mechanistic basis for morphological damage induced by essential oil from Brazilian pepper tree, Schinus terebinthifolia, on larvae of Stegomyia aegypti, the dengue vector.

BACKGROUND: Dengue has become the subject of public health programs worldwide. The lack of a vaccine and the high environmental risk of synthetic insecticides, arouse the interest in natural products against this vector. This study aimed to determine the chemical composition of the essential oil of ripe fruits and seeds of Schinus terebinthifolia Raddi; to evaluate the essential oil effect on mortality of Stegomyia aegypti (Linnaeus, 1792) larvae; and to characterize the structural damage suffered by larvae and their association with different contents of essential oil. METHODS: Ripe fruits and seeds were crunched and their essential oil was extracted through hydrodistillation, purified, and its phytochemical analysis was carried out through High Resolution Gas Chromatography, coupled with Mass Spectrometry. This essential oil was diluted in a 10-point gradient of 86.22 - 862.20 ppm, at regular intervals of 86.22 ppm. Each point received 50 larvae and the assessments of surviving were made at 24, 48 and 72 hours after inoculation. Structural damage was assessed through measurements of thickness with exoskeleton, evaluating the integrity of the head, thorax, abdominal segments, and air siphon, using ImageJ software. Statistical data analysis was carried out through Logistic Regression and Discriminant Analysis. RESULTS: 56 substances were identified, corresponding to 81.67% of the essential oil composition. Larvae were dose-dependent susceptible to the essential oil; the concentration produced a significant effect on larval mortality. Among the major deformations found in the larvae, it was detected inhibition of chitin synthesis by the activity of the oil, thus reducing the deposition of cuticle layers. CONCLUSION: The essential oil caused death in exposed larvae after 72 hours, in a dose-dependent manner. It also changed the structure of exposed larvae, indicating a direct effect on larval exoskeleton. The results open up possibilities for the use of natural products as an alternative to control dipterans.

Insecticidal activity of the essential oil from fruits and seeds of Schinus terebinthifolia Raddi against African malaria vectors.

BACKGROUND: Alternative insecticides for the control of malaria and filarial vectors are of paramount need as resistance is increasing among classes of insecticides currently in use in the public health sector. In this study, mosquitocidal activity of Schinus terebinthifolia essential oil against Anopheles gambiae s.s., An. arabiensis and Culex quinquefasciatus was assessed in laboratory, semi- field and full- field conditions METHOD: Twenty third instar larvae of both Anopheles gambiae s.s. and Cx. quinquefasciatus were exposed to different dosages of plant extract in both laboratory and semi- field environments. Observation of the mortality response was assessed at intervals of 12, 24, 48 and 72 hours. Adult semi- gravid female mosquitoes were exposed to papers treated with S. terebinthifolia and compared with WHO standard paper treated with alphacypermethrin (0.05%). RESULTS: Gas chromatography, coupled to mass spectrometry, identified 15 compounds from S. terebinthifolia extracts, the most abundant identified compound was δ-3-carene (55.36%) and the least was γ-elemene (0.41%). The density of the oil was found to be 0.8086 g/ml. The effective dosages in the insectary ranged from 202.15 to 2625.20 ppm and were further evaluated in the semi- field situation. In the laboratory, the mortality of Cx. quinquefasciatus ranged from 0.5 to 96.75% while for An. gambiae s.s it was from 13.75 to 97.91%. In the semi- field experiments, the mortality rates observed varied for both species with time and concentrations. The LC50 and LC95 value in the laboratory was similar for both species while in the semi- field they were different for each. In wild, adult mosquitoes, the KT50 for S. terebinthifolia was 11.29 minutes while for alphacypermethrin was 19.34 minutes. The 24 hour mortality was found to be 100.0% for S. terebinthifolia and 75.0% for alphacypermethrin which was statistically significant (P < 0.001). CONCLUSION: The efficacy shown by essential oils of fruits and seeds of S. terebinthifolia has given an opportunity for further investigation of individual components of these plant extracts and to evaluate them in small- scale field trials.

Local knowledge on medicinal plant gardens in a rural community near the Atlantic Rain Forest, southeastern Brazil / Conhecimento local em horta medicinal numa comunidade rural adjacente à Floresta Atlântica no sudeste do Brasil

The present study sought to identify the medicinal plants cultivated in a communal medicinal plant garden in Casimiro de Abreu, Rio de Janeiro State, Brazil, and to access its utilization and importance to the local population based on interviews with the garden's administrator and forty rural users. The Relative Importance Index (RI) was calculated for 96 medicinal species. Twenty-seven species had a RI>1.00, with Aloe vera (L.) Burm. f. and Leonurus sibiricus L. (erva-macaé), having the largest value (2.00). Interviews revealed that the majority of the rural users live in the municipality where the garden is located, visit it on a weekly basis, trust the recommendations of the administrator, and know how to prepare the remedies used. Plants that treat illnesses related to the respiratory system are most sought after. The free use of the garden by the local community, associated with the small initial investment, demonstrates the viability of this public initiative and the value of traditional knowledge, but also calls the authorities attention for their safe human use.

O presente estudo objetivou identificar as plantas medicinais cultivadas em uma horta medicinal, situada no município de Casimiro de Abreu, Rio de Janeiro, Brasil, e diagnosticar o acesso à sua utilização e importância para a população local, baseando-se em entrevistas com o administrador da horta, e quarenta usuários da comunidade. O índice de importância relativa (IR) foi calculado para 96 espécies medicinais e, neste, observou-se que 27 espécies tiveram um RI>1,00, com Aloe vera (L.) Burm. f. e Leonurus sibiricus L. (erva-macaé), atingindo o valor máximo (2,00). As entrevistas revelaram que a maioria dos usuários, residentes nas áreas rurais do município em que a horta está localizada, visitam-na com uma frequência semanal, depositando confiança no reconhecimento da planta e recomendações de uso do administrador, e sabem, em sua maioria, como preparar os remédios utilizados. As espécies que tratam afecções relacionadas ao sistema respiratório são as mais procuradas. O uso livre da horta pela comunidade local, associado com o pequeno investimento inicial, demonstra a viabilidade da iniciativa pública e do valor do conhecimento tradicional, mas também chama a atenção das autoridades para o uso humano de forma segura.

The essential oil of Brazilian pepper, Schinus terebinthifolia Raddi in larval control of Stegomyia aegypti (Linnaeus, 1762).

BACKGROUND: The ability of mosquitoes of the genus Aedes and its allies, such as Stegomyia, to transmit diseases such as dengue and yellow fever, makes them important in public health. This study aims to evaluate the use of the essential oil of Brazilian pepper in biological control of by assessing and quantifying the larvicidal effect against S. aegypti, the only available access to dengue control, and test its risk of genotoxicity with Salmonella typhimurium as an indicator of safety for its environmental use. RESULTS: The density of the oil was 0.8622 g mL-1. Gas chromatography coupled with mass spectrometry revealed six major constituents: δ-3-carene (55.43%), α-pinene (16.25%), sylvestrene (10.67%), germacrene D (2.17), ß-myrcene (1.99%), and isoterpinolene (1.4%). The minimum inhibitory dose to larvae development was 862.20 µg mL-1. The median lethal dose (LD50) of the essential oil for larvae was between the concentrations of 172.44-344.88 µg mL-1. There was no mutagenic risk for the essential oil, since there were no biochemical or morphological changes in S. typhimurium after exposure to the essential oil. CONCLUSIONS: The minimum inhibitory essential oil concentration and the median lethal dose pointed to the value of the use of water dispersions of Brazilian pepper essential oil as an environmental safe natural larvicidal for S. aegypti.

Evaluation of an extract of Brazilian arnica (Solidago chilensis Meyen, Asteraceae) in treating lumbago.

One of the Brazilian arnicas, Solidago chilensis Meyen, is a species of the family Asteraceae. This plant is known by this common name because it shares very similar organoleptic properties with the genus Arnica L., also within the family Asteraceae, that comprises approximately 30 European species of perennial, herbaceous plants. The effectiveness of a fluid extract of S. chilensis used externally for treating lumbago was examined in placebo-controlled double-blind clinical pharmacological studies. Two daily skin applications of a gel containing a 5% extract in glycol were administered for 15 days to ten volunteers in a placebo group and to an equal number in a test group. Statistical analyses of the results demonstrated a significant reduction in the perception of pain and a significant increase in the flexibility of patients in the test group as compared with those receiving only the placebo.