The Survival and Parasitism Rate of Tamarixia radiata (Hymenoptera: Eulophidae) on Its Host Exposed to Beauveriabassiana (Ascomycota: Hypocreales)

The effect of the entomopathogenic fungus Beauveria bassiana (BB-12) on the biological characteristics of Tamarixia radiata parasitizing Diaphorina citri was studied under laboratory conditions. Twenty 3rd–5th instar nymphs were exposed to a single already-mated female parasitoid (1 day old) and removed after 24 h. Subsequently, the nymphs were sprayed at 1, 24 and 48 h post-exposure with 1 × 108 conidial mL−1 suspension. The percentage of parasitism recorded was 22%, 35% and 41% at 1, 24 and 48 h, respectively. The emergence rate varied between 28%, 51% and 49% at 1, 24 and 48 h, respectively. In a subsequent experiment, nymphs of D. citri were sprayed with 1 × 108 conidial mL−1 suspension and then exposed to T. radiata at 1, 24 and 48 h post-spraying to allow for parasitism to occur. The percentage of parasitism recorded was 18%, 27% and 28% at 1, 24 and 48 h, respectively, significantly lower than the parasitism rate recorded in the control (48%). The percentage of emergence varied between 24%, 44% and 45% at 1, 24 and 48 h, respectively. In both experiments, no significant difference was observed in the pre-adult duration (days) and the sex ratio of F1 generation. Meanwhile, significant differences were observed in the longevity of the F1 generation of females and males of T. radiata in a treatment consisting of spraying the fungal suspension and the control. Overall, the findings of the current study revealed a negative interaction between T. radiata and B. bassiana in controlling D. citri nymphs. This outcome is believed to be a result of the antagonistic effects of B. bassiana on the developmental process of the pre-adult stages of the parasitoid. However, our results also show that with a properly timed application (allowing parasitism to occur over an extended period of time before the application of the fungus), T. radiata could potentially be used in combination with B. bassiana for the successful biological control of D. citri. This should be carried out in order to minimize the potentially negative interactions between these two biological agents.

COMPORTAMENTO DIFERENCIAL DE LINHAGENS DE ALGODÃO A Cercospora gossypina

A mancha foliar causada pelo fungo Cercospora sp. tem se tornado uma doença de grande importância para o algodoeiro, destacando-se pela sua alta severidade e grandes perdas econômicas. Uma maneira de potencializar o manejo da doença, encontra-se no uso de cultivares resistentes. Nesse sentido, o presente trabalho teve como objetivo avaliar o comportamento de vinte e cinco genótipos de algodão a Cercospora gossypina. O experimento foi realizado em casa de vegetação, com delineamento em blocos casualizados com quatro repetições por genótipos. Plantas de algodão com 25 dias de idade foram inoculadas com a suspensão fúngica do patógeno. Foram realizadas quatro avaliações de severidade da doença, com início aos sete dias após a inoculação, utilizando-se uma chave descritiva. Foram calculadas, a área sob a curva de progresso da doença para cada genótipo avaliado. Os genótipos FM 906, FM 975, CNPA 2015 126 B2 RFRL2, CNPA 2015 82 B2RFRL2, BRS 432 B2RF, TMG 44, CNPA 2015 231 B2RF, CNPA 2015 530 B2RF, TMG 81 WS, FM 954, CNPA 2014 155 B2RF, FM 975 GLT, DP 1536 B2RF, CNPA 2015 512 B2RF e FM 983 apresentaram os menores índices de severidade da doença. Estudos que caracterizem os níveis de suscetibilidade de genótipos de algodão em relação a doença são fundamentais, a fim de selecionar os mais adequados ao manejo da doença. Palavras-chave: suscetibilidade; Gossypium L.; mancha de cercospora. Differential behavior of cotton lines Cercospora gossypina ABSTRACT: Leaf spot caused by the fungus Cercospora sp. has become a disease of great importance for cotton, standing out for its high severity and great economic losses. One way to improve the management of the disease is the use of resistant cultivars. In this sense, the objective of the present work was to evaluate the behavior of twenty-five cotton lines against Cercospora gossypina. The experiment was conducted in a greenhouse, with randomized block design and four repetitions per line. Cotton plants with 25 days of age were inoculated with fungal suspension of the pathogen. Four evaluations of disease severity were performed, starting at seven days after inoculation, using a descriptive key. The area under the disease progress curve was calculated for each genotype evaluated. The strains FM 906, FM 975, CNPA 2015 126 B2 RFRL2, CNPA 2015 82 B2RFRL2, BRS 432 B2RF, TMG 44, CNPA 2015 231 B2RF, CNPA 2015 530 B2RF, TMG 81 WS, FM 954, CNPA 2014 155 B2RF, FM 975 GLT, DP 1536 B2RF, CNPA 2015 512 B2RF and FM 983 showed the lowest disease severity rates. Studies that characterize the susceptibility levels of cotton strains in relation to the disease are fundamental in order to select the most suitable for disease management. Keywords: susceptibility; Gossypium L; cercospora spot.

Description using ultramorphological techniques of the infection of Beauveria bassiana (Bals.-Criv.) Vuill. in larvae and adults of Atta sexdens (Linnaeus, 1758) (Hymenoptera: Formicidae)

Leaf-cutting ants, whose name comes from the habit of cutting leaves and other parts of plants, are dominant herbivores in the Americas, attacking different crops to keep symbiotic fungi (their main food source) in the colony. These ants are soil inhabitants, an environment rich in microorganisms, many of which are considered entomopathogenic. In order to describe a kind of microbial biological control of these ants through histological techniques, we used the fungus Beauveria bassiana (Bals.- Criv.) Vuill. Larvae and adult workers of Atta sexdens (Linnaeus, 1758) were exposed to a fungal suspension with the concentration of 106/conidia/mL. The specimens were adequately prepared to describe the behavior of the fungus on the integument at 24, 48 and 72 hours after initial exposure. Some specimens were used to represent these periods, being properly processed for scanning electron microscopy, which was applied to document the fungus development on the surface of the insect integument. To better understand the dynamics of the fungal infection, from the conidial adhesion to the potential colonization of the insides of the insect, the histological technique with HE staining was applied. The results showed that, in immature individuals, the hyphal penetration of B. bassiana fungi into the insect integument occurred in 48 h.

Assess the severity of Sclerotinia sclerotiorum isolate on peas Pisum sativum. L

Pisum sativum. L is one of the most important legumes and vegetables. It is an essential source of energy and highly rich in protein. Peas are affected by many plant diseases, Sclerotinia sclerotiorum, which affects many vegetable and field crops plants causing significant losses in agricultural production. S. sclerotiorum was isolated from infected pea pods on Potato Dextrose Agar (PDA) media. the percentage of seed germination was investigated for both local and Italian varities, also the effect of fungus on seeds and bodes was evaluated. Results of this study showed that the percentage of seed germination in the local varity was 98%, while in the Italian varity 90%. The ability of pathogenicity was high on seeds and bods of the local variety. and also the effect of S. sclerotiorum suspension when using perlite showed that the fungus hed a high effecte on the plant growth and seed germination comparied with sclerotia treatment on local variety only, while the effect of fungal suspension decreased seed and plant germination on petmous comparied with sclerotia treatment.

Uji Aktivitas Antifungi Ekstrak Daun Sirih (Piper betle L) Terhadap Saprolegnia sp. Secara In Vitro [Antifungal Activities Test Of Betel Leaf Extract (Piper betle L) On Saprolegnia sp. By In Vitro]

Saprolegniasis is a mycotic disease caused by Saprolegnia sp. that usually attacking wild fish and farming fish. Saprolegnia sp. cause a lot of harm in process of the fish cultivation. Prevention and treatment of the common practice is use chemical drugs, but the use of these chemicals tend to be environmentally unfriendly and there are has karsinogenik effect. Therefore, the use of traditional medicines is one of alternative to control Saprolegnia sp. safer than chemical drugs. Green betel leaf contains phenolic compounds and tannins are efficacious as antifungal agent. This study aims to prove the antifungal activity of extracts of betel leaf (Piper betle L) for Saprolegnia sp., and to know the minimum concentration of betel leaf extract (Piper betle L) as antifungal for Saprolegnia sp. The design of this experiment is used completely randomized design (CRD) with 11 treatments and 3 replications. This study used the dilution method through the Minimum Inhibitory Concentration determination (MIC) and Minimum Fungicidal Concentration (MFC). The concentration of the extract used was 50% (0.5 g/ml), 25% (0.25 g/ml), 12.5% (0.125 g/ml), 6.25% (0.0625 g/ml), 3.13% (0.0313 g/ml), 1.56% (0.0156 g/ml), 0.78% (0.0078 g/ml), 0.39% (0.0039 g/ml), 0.2% (0.002 g/ml) of betel leaf extract. A positive control containing 2 ml of 3% hydrogen peroxide were added fungal suspension until 4 ml Negative control containing 2 ml of 10% DMSO were added fungal suspension until 4 ml. The main parameters in this study is the value of optical density (OD) for MIC (Minimum Inhibitory Concentration) test and the absence of Saprolegnia sp. growing on SDA media for MFC (Minimum Fungicidal Concentration) test. 0.20% (0.002g/ml) concentration of of betel leaf extract is the minimum concentration that can inhibit the growth of Saprolegnia sp. MFC test results showed concentrations of 0.78% (0.0078 g/ml) betel leaf extract is the minimum concentration that can kill Saprolegnia sp.

Patogenitas Isolat Jamur Entomopatogenik Metarhizium anisopliae terhadap Lalat Rumah Musca domestica L. (Diptera: Muscidae)

Metarhizium anisopliae is one of the entomopathogenic fungi that can be used to control house fly, Musca domestica. The aim of this study is to determine the effectiveness of fungus Metarhizium anisopliae in killing house flies. This study used a Completely Randomized Design (CRD) with 5 treatment concentration of Metarhizium anisopliae fungal suspension concentration of 1x106 conidia/mL, 3x106 conidia/mL, 5x106 conidia/mL, 7x106 conidia/mL, 9x106 conidia/mL with each repetition three times. The fungal pathogenicity was determined by the lethal time of 50% flies (LT50) for each concentration using Probit analysis. The result of this study showed that the time required to killing 50% of flies in consecutive consentrations was 7 days with concentrations ranging from 3x106 conidia/mL until 5x106 conidia/mL. In conclusion, the fungus Metarhizium anisopliae is effectively deadly pest house flies Musca domestica.

Antifungal effect of Satureja khuzestanica Jamzad essential oil on oral candidiasis in immunosuppressed rats

Summary Introduction: The antimicrobial, antibacterial, antioxidant, antihyperlipidaemic, antidiabetic, anti-inflammatory and analgesic effects of Satureja khuzestanica (Lamiaceae) have been investigated in numerous studies. Objective: The antifungal effects of S. khuzestanica essential oil (SKJO) in immunosuppressed rats suffering from oral candidiasis were investigated. Methods: A fungal suspension with a density of 3×108 CFU/ml was taken from the isolate of a case with acute vaginitis. In order to achieve a medicinal formulation, accurate twice the minimum inhibitory concentration (MIC) of SKJO and 10 times MIC of nystatin was used with 0.8% agar as a base material. In this study, 35 rats divided into 5 groups each of 7 were used. The assessment of level of infection and specification of the effects of treatment were performed using microbiological and histopathological methods as well as clinical examinations. Results: Our results show that carvacrol is the main compound of SKJ essential oil. Lesions completely disappeared in both treatment groups (SKJO and nystatin) after 8 days of treatment. Furthermore, in groups treated with SKJO and nystatin, the quantities of mean logarithm of colony forming unit (CFU) were 85.62% and 90.62%, respectively, in comparison with placebo group. Also, histopathological properties suggested no infection in groups who had clean and normal dorsal tongue mucosa. Conclusions: Using SKJO with twice accuracy it was concluded that MIC in immunosuppressed rats was quite successful in a time of a week and equal with that of a nystatin treatment with an accuracy of 10 times the MIC.

Potential of transmission of Pyricularia graminis-tritici from plant to seed and from seed to seedling in wheat genotypes with different degrees of blast resistance

Transmission studies of Pyricularia graminis-tritici by wheat seed can help establishing pathogen tolerance standards in crops. Four genotypes, each one with different responses to blast, were inoculated with five volumes of fungal suspension (1,5x105 spores.mL-1), in order to obtain 0, 5, 10, 20 and 30% of plants inoculated in the experimental unit. The potential of transmission of P. graminis-tritici from plant to seed was evaluated by the incidence of the fungus in the seeds produced. Under controlled conditions, the transmission rate of the fungus from seed to seedling was evaluated. Blast incidence in field allowed a high incidence of P. graminis-tritici in the seeds, especially in the genotypes considered susceptible. The transmission of fungus from the seeds to seedlings occurred 7, 14 and 21 days after sowing, at low rates. There was a relationship between the presence of blast in field and the incidence of P. graminis-tritici in seeds produced by the genotypes BRS 264, VI 98053, CD 116 and CD 104. Inoculation of 5, 10, 20 and 30% of plants with fungus can generate a high incidence of the pathogen in field and in the seeds produced, but it doesn`t guarantee a high transmission rate from seed to seedling, which is low under controlled conditions.

Susceptibility of Ephestia cautella ( Walk.) to entomopathogenic fungus Verticillium lecanii (Zimm.) Preparation

The study conducted in the laboratory of Biology department – College of Science – University of wasit, aimed to evaluate the efficacy of spores suspension concentrations of Verticillium lecanii (Zimm.) against (eggs , larvae , pupae and adults) of moth Ephestia cautella (Walk.) by direct application to insect at ( 25 ± 1 °C and 65 ± 5% R.h. and photoperiod 14 L:10 D h(.The results showed that all fungal suspension concentrations (103,105,107) spore/ml affected on different stages of insect after ( 2 ,5 , 10) day of the treatment compared with control treatment. The laboratory results revealed that the all concentrations of spores suspension of V. lecanii affect the mortality of eggs of moth after 2 day of the treatment and the percentage of mortality were 100%, and shown that the percentage mortality of larval stages and pupae were 100% when they were treated for 5 day at107spore/ml followed by the another treatments in concentrations of 105,103 spore/ml after 10 day of the treatment were 100%. On the other hand, bioassays conducted to evaluate the effect of direct exposure of adults to the concentrations(103,105,107) spore/ml and it revealed that all adults ( males and females) were killed after 10 day of the treatment and the highest percentage of mortality in males and females was100% and the LC50 values of males were 6.2 x104 and females 6.5x105 spore / ml. The results of this study were revealed the success and effectiveness of using the Verticillium lecanii fungus suspension at (103,105,107) spore/ml as a pathogen in the control of moth Ephestia cautella laboratory.