Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59%), geraniol (18,81%) and citronellol (11,74%). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.

Growth inhibition and morphological alterations of Trichophyton rubrum induced by essential oil from Cymbopogon winterianus Jowitt ex Bor

Trichophyton rubrum is one of the most common fungi causer of dermatophytosis, mycosis that affect humans and animals around the world. Researches aiming new products with antifungal activity become necessary to overcome difficulties on treatment of these infections. Accordingly, this study aimed to investigate the antifungal activity of essential oil from Cymbopogon winterianus against the dermatophyte T. rubrum. The antifungal screening was performed by solid medium diffusion method with 16 T. rubrum strains, minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined using the microdilution method. The effects on mycelial dry weight and morphology were also observed. Screening showed essential oil in natura inhibited all the tested strains, with inhibition zones between 24-28 mm diameter. MIC50 and MIC90 values of the essential oil were 312 µg/mL for nearly all the essayed strains (93.75 %) while the MFC50 and MFC90 values were about eight times higher than MIC for all tested strains. All tested essential oil concentrations managed to inhibit strongly the mycelium development. Main morphological changes on the fungal strains observed under light microscopy, which were provided by the essential oil include loss of conidiation, alterations concerning form and pigmentation of hyphae. In the oil presence, colonies showed folds, cream color and slightly darker than the control, pigment production was absent on the reverse and with evident folds. It is concluded that C. winterianus essential oil showed activity against T. rubrum. Therefore, it could be known as potential antifungal compound especially for protection against dermatophytosis.

Chemical composition and antifungal activity of Hyptis suaveolens (L.) poit leaves essential oil against Aspergillus species

This study aimed to identify the constituents of the essential oil from Hyptis suaveolens (L.) leaves using a Gas Chromatograph -Mass Spectrometer and assess its inhibitory effect on some potentially pathogenic Aspergilli (A. flavus, A. parasiticus, A. ochraceus, A. fumigatus and A. niger). Eucaliptol (47.64 %) was the most abundant component in the oil, followed for gama-ellemene (8.15 %), beta-pynene (6.55 %), (+)3-carene (5.16 %), trans-beta-cariophyllene (4.69 %) and germacrene (4.86 %). The essential oil revealed an interesting anti-Aspergillus property characterized by a Minimum Inhibitory Concentration and Minimum Fungicidal Concentration of 40 and 80 µL/mL, respectively. The oil at 80 and 40 µL/mL strongly inhibited the mycelial growth of A. fumigatus and A. parasiticus along 14 days. In addition, at 10 and 20 µL/mL the oil was able to cause morphological changes in A. flavus as decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure suggesting fungal wall degeneration. These findings showed the interesting anti-Aspergillus property of H. suaveolens leaves essential oil supporting its possible rational use as alternative source of new antifungal compounds to be applied in the aspergillosis treatment.

Capacity of earwig Marava arachidis (Yersin) to access fennel plants Foeniculum vulgare Mill in laboratory and field

This research was aimed at obtaining data about earwig behavior (Marava arachidis Y.) on fennel agro-ecosystems and evaluating its potential capacity to access plants in the absence of aphids under laboratory and field conditions. This study establishes a baseline to evaluate earwigs as biological controls to combat aphids that attack fennel plants. Two experiments were developed. In experiment 1, earwigs were studied under laboratory conditions, in experiment 2 under field conditions. Independent variables were sex, exposure to the essential oil of fennel for 24 or 48 hours, and whether the fennel plant was vegetative or flowering. The results indicated that earwigs will climb a fennel plant in the absence of aphids and that few statistical significant results were obtained among the independent variables examined. A difference between male and females was noted in the field experiment in animals receiving 48 h of exposure to the essential oil of fennel. The terminal height reached by males and females in the 48 h vegetative and flower condition also differed.

Este trabalho objetivou obter os primeiros dados a respeito da tesourinha (Marava arachidis Y.) em agroecossistema de erva-doce, além de avaliar sua capacidade potencial em acessar essas plantas na ausência de afídeos, em laboratório e campo, permitindo futuros trabalhos visando a seu uso no controle biológico para combater os afídeos que atacam essa cultura. Assim, dois experimentos foram realizados, sendo que no experimento 1 as tesourinhas foram estudadas em condições de laboratório e no segundo experimento em condições de campo. As variáveis independentes observadas foram: sexo, exposição a óleo essencial de erva-doce por 24 e 48 horas, em plantas no estágio vegetativo e reprodutivo. Os resultados indicaram que as tesourinhas acessam as plantas na ausência de afídeos e que existem poucas diferenças entre as variáveis estudadas. A diferença entre os machos e as fêmeas foi observada em campo quando os insetos foram expostos por 48 horas a óleo essencial de erva-doce. A altura máxima atingida pelos machos e pelas fêmeas, quando expostos ao óleo essencial de erva-doce por 48 horas nos estágios vegetativos e de florescimento, também diferiram.

Capacity of earwig Marava arachidis (Yersin) to access fennel plants Foeniculum vulgare Mill in laboratory and field

This research was aimed at obtaining data about earwig behavior (Marava arachidis Y.) on fennel agro-ecosystems and evaluating its potential capacity to access plants in the absence of aphids under laboratory and field conditions. This study establishes a baseline to evaluate earwigs as biological controls to combat aphids that attack fennel plants. Two experiments were developed. In experiment 1, earwigs were studied under laboratory conditions, in experiment 2 under field conditions. Independent variables were sex, exposure to the essential oil of fennel for 24 or 48 hours, and whether the fennel plant was vegetative or flowering. The results indicated that earwigs will climb a fennel plant in the absence of aphids and that few statistical significant results were obtained among the independent variables examined. A difference between male and females was noted in the field experiment in animals receiving 48 h of exposure to the essential oil of fennel. The terminal height reached by males and females in the 48 h vegetative and flower condition also differed.

Este trabalho objetivou obter os primeiros dados a respeito da tesourinha (Marava arachidis Y.) em agroecossistema de erva-doce, além de avaliar sua capacidade potencial em acessar essas plantas na ausência de afídeos, em laboratório e campo, permitindo futuros trabalhos visando a seu uso no controle biológico para combater os afídeos que atacam essa cultura. Assim, dois experimentos foram realizados, sendo que no experimento 1 as tesourinhas foram estudadas em condições de laboratório e no segundo experimento em condições de campo. As variáveis independentes observadas foram: sexo, exposição a óleo essencial de erva-doce por 24 e 48 horas, em plantas no estágio vegetativo e reprodutivo. Os resultados indicaram que as tesourinhas acessam as plantas na ausência de afídeos e que existem poucas diferenças entre as variáveis estudadas. A diferença entre os machos e as fêmeas foi observada em campo quando os insetos foram expostos por 48 horas a óleo essencial de erva-doce. A altura máxima atingida pelos machos e pelas fêmeas, quando expostos ao óleo essencial de erva-doce por 48 horas nos estágios vegetativos e de florescimento, também diferiram.

Mecanismos de ação de himenópteros parasitóides sobre Megastes spp. (Lepidoptera: Pyralidae) em agroecossistema de batata-doce (Ipomoea batatas L.)

The presence and action of Hymenoptera parasitoids in agroecossystems of sweet potato (Ipomoea batatas L.) in Pedra de Fogo county - PB, Brazil, on Megastes spp. complex were studied, with the objective of identifying parasitoids species and to describe the main aspects on parasitism action on Megastes grandalis Guenee and Megastes pusialis Snellen. On direct evaluation 14% of plants had females of ectopasitoids belonging to the braconidae family. The indirect evaluation showed the occurrence of 22% of worms attacked by parasitoids. The emergence of parasitoids adults of seven species belonging to the braconidae, Chalcididae and Ichneumonidae families has been observed. It was concluded that the presence of parasitoids in sweet potato agroecossystem is diversified and important to suppress the insect pest.

Estudaram-se a presença e a ação de himenópteros parasitóides em agroecossistema de batata-doce (Ipomoea batatas L.) no município de Pedra de Fogo - PB, sobre o complexo Megastes spp, com o objetivo de identificar as espécies de parasitóides existentes, bem como descrever os principais eventos na ação de parasitismo sobre Megastes grandalis Guenee e Megastes pusialis Snellen. No levantamento direto, em 14% das plantas, existiam fêmeas de microhimenópteros ectoparasitóides da família braconidae atacando lagartas de Megastes spp. No levantamento indireto, constatou-se um ataque de parasitóide em 22% das lagartas, emergindo adultos de sete espécies das famílias braconidae, Chalcididae e Ichneumonidae, com predominância de braconídeos ectoparasitóides. Concluiu-se que a presença de parasitóides no agroecossistema da batata-doce é bastante diversificada e proporcionam uma boa contribuição na mortalidade natural da praga.

Efeito de quatro tipos de mel na longevidade e reprodução de Catolaccus grandis (Hymenoptera:pteromalidae)

The aim of this work was to investigate the best type of honey in relation to longevity and life fertility of Catolaccus grandis. Recent emerged adults were transferred to 500ml plastic recipients adapted to supply water and moisture to insects. A couple of parasite was kept for each recipient in climatic chamber at 25±1°C, RH = 70±10% and photofase 14h. The work had four treatments: orange, wild plant species honey, Jatai Tetragonistica angustula and sugar cane honey with fifteen replications each. Recent emerged adults received five Euscepes postfasciatus larvae, which were encapsulated in parafilm. Three drops of honey from respective treatment were placed on parafilm. Longevity of males and females were calculated, as well as the number of eggs female-1. Tables of fertility were made. The best diets to feed adults of C. grandis were wild plant species honey and orange honey; the best fecundity was observed on orange honey diet (101,60 eggs female-1) and the parameters of life fertility table were obtained using diets based on orange honey and wild plant species honey.

O trabalho teve como objetivo conhecer o melhor tipo de mel em relação à longevidade e fertilidade do parasitóide do bicudo-do-algodoeiro Catolaccus grandis. Adultos recém-emergidos foram transferidos para recipientes plásticos de 500mL, adaptados com tubo para fornecer água e umidade para os insetos. Um casal do parasitóide foi mantido em cada recipiente em câmara climatizada a 25±1°C, UR = 70±10% e fotoperíodo de 14h. O trabalho constou de 4 tratamentos: mel de flor de laranjeira; mel de flores de plantas silvestres; mel de cana-de-açúcar (todos produzidos por Apis mellifera) e mel de flores silvestres produzido por abelha Jataí (Tetragonistica angustula), com 15 repetições cada. Adultos recém-emergidos do parasitóide receberam cinco larvas de Euscepes postfasciatus encapsuladas em parafilm. Três gotículas de mel foram colocadas sobre o parafilm. Calculou-se a longevidade de machos e fêmeas, número de ovos dia-1 fêmea-1 e número total de ovos fêmea-1 e construíram-se as tabelas de fertilidade. As melhores dietas para alimentar adultos de C. grandis foram o mel silvestre e o de laranjeira. A melhor fecundidade foi observada na dieta de mel de laranjeira (101,60 ovos fêmea-1) e os melhores resultados para aumento reprodutivo e populacional deste parasitóide foram obtidos com mel de laranja e com mel silvestre.

Efeito de quatro tipos de mel na longevidade e reprodução de Catolaccus grandis (Hymenoptera:pteromalidae)

The aim of this work was to investigate the best type of honey in relation to longevity and life fertility of Catolaccus grandis. Recent emerged adults were transferred to 500ml plastic recipients adapted to supply water and moisture to insects. A couple of parasite was kept for each recipient in climatic chamber at 25±1°C, RH = 70±10% and photofase 14h. The work had four treatments: orange, wild plant species honey, Jatai Tetragonistica angustula and sugar cane honey with fifteen replications each. Recent emerged adults received five Euscepes postfasciatus larvae, which were encapsulated in parafilm. Three drops of honey from respective treatment were placed on parafilm. Longevity of males and females were calculated, as well as the number of eggs female-1. Tables of fertility were made. The best diets to feed adults of C. grandis were wild plant species honey and orange honey; the best fecundity was observed on orange honey diet (101,60 eggs female-1) and the parameters of life fertility table were obtained using diets based on orange honey and wild plant species honey.

O trabalho teve como objetivo conhecer o melhor tipo de mel em relação à longevidade e fertilidade do parasitóide do bicudo-do-algodoeiro Catolaccus grandis. Adultos recém-emergidos foram transferidos para recipientes plásticos de 500mL, adaptados com tubo para fornecer água e umidade para os insetos. Um casal do parasitóide foi mantido em cada recipiente em câmara climatizada a 25±1°C, UR = 70±10% e fotoperíodo de 14h. O trabalho constou de 4 tratamentos: mel de flor de laranjeira; mel de flores de plantas silvestres; mel de cana-de-açúcar (todos produzidos por Apis mellifera) e mel de flores silvestres produzido por abelha Jataí (Tetragonistica angustula), com 15 repetições cada. Adultos recém-emergidos do parasitóide receberam cinco larvas de Euscepes postfasciatus encapsuladas em parafilm. Três gotículas de mel foram colocadas sobre o parafilm. Calculou-se a longevidade de machos e fêmeas, número de ovos dia-1 fêmea-1 e número total de ovos fêmea-1 e construíram-se as tabelas de fertilidade. As melhores dietas para alimentar adultos de C. grandis foram o mel silvestre e o de laranjeira. A melhor fecundidade foi observada na dieta de mel de laranjeira (101,60 ovos fêmea-1) e os melhores resultados para aumento reprodutivo e populacional deste parasitóide foram obtidos com mel de laranja e com mel silvestre.

Mecanismos de ação de himenópteros parasitóides sobre Megastes spp. (Lepidoptera: Pyralidae) em agroecossistema de batata-doce (Ipomoea batatas L.)

The presence and action of Hymenoptera parasitoids in agroecossystems of sweet potato (Ipomoea batatas L.) in Pedra de Fogo county - PB, Brazil, on Megastes spp. complex were studied, with the objective of identifying parasitoids species and to describe the main aspects on parasitism action on Megastes grandalis Guenee and Megastes pusialis Snellen. On direct evaluation 14% of plants had females of ectopasitoids belonging to the braconidae family. The indirect evaluation showed the occurrence of 22% of worms attacked by parasitoids. The emergence of parasitoids adults of seven species belonging to the braconidae, Chalcididae and Ichneumonidae families has been observed. It was concluded that the presence of parasitoids in sweet potato agroecossystem is diversified and important to suppress the insect pest.

Estudaram-se a presença e a ação de himenópteros parasitóides em agroecossistema de batata-doce (Ipomoea batatas L.) no município de Pedra de Fogo - PB, sobre o complexo Megastes spp, com o objetivo de identificar as espécies de parasitóides existentes, bem como descrever os principais eventos na ação de parasitismo sobre Megastes grandalis Guenee e Megastes pusialis Snellen. No levantamento direto, em 14% das plantas, existiam fêmeas de microhimenópteros ectoparasitóides da família braconidae atacando lagartas de Megastes spp. No levantamento indireto, constatou-se um ataque de parasitóide em 22% das lagartas, emergindo adultos de sete espécies das famílias braconidae, Chalcididae e Ichneumonidae, com predominância de braconídeos ectoparasitóides. Concluiu-se que a presença de parasitóides no agroecossistema da batata-doce é bastante diversificada e proporcionam uma boa contribuição na mortalidade natural da praga.