scholarly journals Virulence of Five Isolates of Indigenous Beauveria Bassiana Against Eggs and Nymphs of Bemisia Tabaci Gennadius (Hemiptera: Aleyrodidae)

2021 ◽  
Vol 9 (1) ◽  
pp. 54-61
Author(s):  
Gita Flawerina ◽  
Trizelia Trizelia ◽  
Nurbailis Nurbailis
Keyword(s):  
Beauveria Bassiana ◽  
Bemisia Tabaci ◽  
Adult Emergence ◽  
Fungal Isolates ◽  
Experimental Parameters ◽  
Conidial Concentration

This research aims to study the virulence of five isolates of Beauveria bassiana to eggs and nymphs of Bemisia tabaci on tomato. In the experiment eggs and second instar nymphs of B. Tabaci were used. Five isolates of the fungus, i.e., WS, TD312, PD114, PA221, PB211, were tested. Conidial concentration of B. bassiana used were 108 conidia/ml. Experimental parameters included mortality of eggs and nymph and percentage of adult emergence. The results showed that all B. bassiana isolates tested were able to kill B. tabaci eggs but with very low mortality (2-19%). Mortality of second instar B. tabaci nymphs was dependent on the fungal isolates. Isolate WS had the highest virulence, which caused 70% mortality of 2nd instar nymphs, with a LT50 of 4.87 days. Nymphs of B. tabaci were highly susceptible to B. bassiana infection compared with eggs. B. bassiana applicated to nymphs of B. tabaci can decrease the percentage of adult emergence.

scholarly journals Effect of the native strain of the predator Nesidiocoris tenuis Reuter and the entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium against Bemisia tabaci (Genn.) under greenhouse conditions in Tunisia

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Besma Hamrouni Assadi ◽  
Sabrine Chouikhi ◽  
Refki Ettaib ◽  
Naima Boughalleb M’hamdi ◽  
Mohamed Sadok Belkadhi
Keyword(s):  
Beauveria Bassiana ◽  
Bemisia Tabaci ◽  
Entomopathogenic Fungi ◽  
Tobacco Plant ◽  
Economic Losses ◽  
Native Strain ◽  
Lecanicillium Muscarium ◽  
Southern Tunisia ◽  
Significant Efficacy ◽  
Nesidiocoris Tenuis

Abstract Background The misuse of chemical insecticides has developed the phenomenon of habituation in the whitefly Bemisia tabaci (Gennadius) causing enormous economic losses under geothermal greenhouses in southern Tunisia. Results In order to develop means of biological control appropriate to the conditions of southern Tunisia, the efficacy of the native strain of the predator Nesidiocoris tenuis Reuter (Hemiptera: Miridae) and two entomopathogenic fungi (EPF) Beauveria bassiana and Lecanicillium muscarium was tested against Bemisia tabaci (Gennadius). Indeed, the introduction of N. tenuis in doses of 1, 2, 3, or 4 nymphs per tobacco plant infested by the whitefly led to highly significant reduction in the population of B. tabaci, than the control devoid of predator. The efficacy of N. tenuis was very high against nymphs and adults of B. tabaci at all doses per plant with a rate of 98%. Likewise, B. bassiana and L. muscarium, compared to an untreated control, showed a very significant efficacy against larvae and adults of B. tabaci. In addition, the number of live nymphs of N. tenuis treated directly or introduced on nymphs of B. tabaci treated with the EPF remained relatively high, exceeding 24.8 nymphs per cage compared to the control (28.6). Conclusions It can be concluded that the native strain of N. tenuis and the EPF tested separately were effective against B. tabaci. Their combined use appears to be possible.

scholarly journals Is High Whitefly Abundance on Cassava in Sub-Saharan Africa Driven by Biological Traits of a Specific, Cryptic Bemisia tabaci Species?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal
Keyword(s):  
Food Security ◽  
Bemisia Tabaci ◽  
Development Time ◽  
Adult Emergence ◽  
Sub Saharan Africa ◽  
Biological Traits ◽  
Population Development ◽  
Species Classification ◽  
First Instar ◽  
Sub Saharan

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.

scholarly journals Biological activities of spores and metabolites of some fungal isolates on certain aspects of the spiny bollworms Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Eman Mohammed Abd-ElAzeem ◽  
Warda Ahmed Zaki El-Medany ◽  
Hend Mohammed Sabry
Keyword(s):  
Biological Activities ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Pupal Weight ◽  
Earias Insulana ◽  
Dead Larva ◽  
Fungal Isolates ◽  
Protease Enzyme ◽  
Newly Hatched Larvae ◽  
Lepidoptera Noctuidae

AbstractBiological activities of spores and metabolites of some fungi isolated from dead larva of the spiny bollworms (SBW), Earias insulana (Boisd.) (Lepidoptera: Noctuidae), against the newly hatched larvae of the pest were carried out. Results showed that the fungi Metarhizium anisopliae, Acremonium sp., and Paecilomyces variotii had affected the newly hatched larvae of (SBW). Acremonium sp. was the most potent one as it had the highest newly hatched larval mortality percentage (65 and 58.33%) for its spore suspension and metabolites, respectively, while the lowest one (41%) was for P. variotii metabolites. Also, spore suspensions of the all fungal isolates had the highest larval mortality than fungal metabolites. Studying the enzymatic activity showed that Acremonium sp. produced protease enzyme on media containing gelatin, which caused the highest larval mortality (72.22%).These isolates showed different effects on all stages of the pest and decreased pupal weight, adult emergence percentages, deposited eggs, and hatchability percentages than the control. Identification of Acremonium sp. EZ1 was confirmed using 18 s rRNA and its accession number MN25101.

scholarly journals Scanning electron microscopic studies of Beauveria bassiana against Lipaphis erysimi Kalt

2017 ◽  
Vol 9 (1) ◽  
pp. 461-465
Author(s):  
Tanvi Sharma ◽  
Neelam Joshi ◽  
Anu Kalia
Keyword(s):  
Beauveria Bassiana ◽  
Lipaphis Erysimi ◽  
Electron Microscopic ◽  
Time Intervals ◽  
Mustard Aphid ◽  
Commercial Formulation ◽  
Fungal Isolates ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Scanning Electron

This work was aimed to identify the LC50 of the indigenous fungal isolates for controlling L. erysimi infesta-tion in mustard aphid besides to probe the mechanism of action of the local isolates and comparison of the efficacy with the reference culture and commercial formulation ‘Mycojaal’. Three isolates of entomopathogenic fungi Beauveria bassiana were tested for infection on nymph of Lipaphis erysimi Kalt. using scanning electron microscopy (SEM) to record any variation. The SEM revealed adhesion of spores of B.bassiana followed by penetration of L.erysimi nymph surface. It was observed that all Beauveria isolates showed little variation with respect to penetration and adhesion at different time intervals. Further, lethal concentration (LC50) values of B. bassiana isolates against L. erysimi was recorded and was lowest (0.05x107 spores/ml) in B. bassiana MTCC 4495 and highest (0.11.X107 spores/ml) was recorded in native isolate F10 after 120 hours of treatment. The study has established the need for the isolation and evaluation of the indigenous Beauveria isolate. Moreover, it also exhibited the efficacy of the reference and commercially available biocontrol agents.

scholarly journals Phototoxicity of Ultraviolet-A against the Whitefly Bemisia tabaci and Its Compatibility with an Entomopathogenic Fungus and Whitefly Parasitoid

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Muhammad Musa Khan ◽  
Ze-Yun Fan ◽  
Dylan O’Neill Rothenberg ◽  
Jing Peng ◽  
Muhammad Hafeez ◽  
...  
Keyword(s):  
Biological Control ◽  
Bemisia Tabaci ◽  
Exposure Time ◽  
Entomopathogenic Fungus ◽  
Light Exposure ◽  
Adult Emergence ◽  
Biological Control Agents ◽  
Encarsia Formosa ◽  
Parasitism Rate ◽  
Invertebrate Pests

Ultraviolet (UV) radiation significantly affects insect life and, as a result, has been widely used to control different invertebrate pests. The current results demonstrate that when Bemisia tabaci first instar nymphs are exposed to UV-A light for 12, 24, 48, and 72 h, their developmental and biological parameters are negatively affected by UV-A exposure; the effect increased with an increase in exposure time. We hypothesized that UV-A light is compatible with other biological control agents. Results showed that when the entomopathogenic fungus Cordyceps fumosorosea was applied to third instar nymphs of B. tabaci previously exposed to UV-A light, the LC50 was 3.4% lower after 72 h of exposure to UV-A light compared to the control. However, when the fungus was exposed to UV-A light, its virulence decreased with an increase in UV-A exposure time. The parasitism rate of Encarsia formosa against 24 h UV-A-exposed third instar nymphs of B. tabaci increased while the adult emergence from parasitized nymphs was not affected after UV-A light exposure. Parasitism rate was significantly reduced however following E. formosa exposure to UV-A light; but again, adult emergence was not affected from parasitized nymphs. The percentage mortality of E. formosa increased with increasing exposure time to UV-A light. The enzyme activity of SOD, CAT, GST, and AChE and the energy reserve contents were negatively affected due to UV-A exposure. Collectively, this study has demonstrated that UV-A light significantly suppresses the immune system of B. tabaci and that UV-A light is compatible with other biological control agents if it is applied separately from the biological agent.

scholarly journals USE OF INDIGENOUS ISOLATES OF METARHIZIUM, ISARIA AND BEAUVERIA AS POTENTIAL BIO-CONTROL AGENTS AGAINST Sitophilus oryzae UNDER LABORATORY CONDITIONS

2019 ◽  
Vol 56 (04) ◽  
pp. 1037-1044
Author(s):  
Saif-Ur Rehman
Keyword(s):  
Chemical Control ◽  
Multiple Dose ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Immersion Method ◽  
New Class ◽  
Laboratory Conditions ◽  
Dose Comparison ◽  
Fungal Isolates ◽  
Conidial Concentration

Entomopathogenic fungi (EPF) are suggested as a new class of alternates followed by Synthetic chemical control of the insect pests .Virulence of seven EPF isolates, four strains of Metarhizium {(Qin-08, Qin-13, Qin-18 and ME-38 (LT-178)}, two of Isaria {ME-33 (ILT-01), Yulin-5 (IYL-01)} and one of Beauveria bassiana (Qin-21) were assessed against the adults of Sitophilus oryzae under laboratory conditions, firstly at single conidial concentration (1x108 ml-1 ) by immersion and the food mix methods. Qin-21, ME-33 and Qin-18 caused significantly highest mortality of S.oryzae at immersion methods (100, 100 and 98%), followed by food mix method to 100, 84.16 and 91.66% respectively. Yulin-5 was the least effective, showing significantly the lowest mortality at food mixed (32.49%) and immersion methods (40.20%) respectively. Hence, the immersion method was found to be most effective, resulting the higher mortality rate of S. oryzae in comparison to food mix method, in all tested fungal isolates. Secondly, we screened out the most effective isolates for multiple dose comparison i.e., 1x104 to 1x107 conidia ml-1 by immersion method only. The isolate ME-33 resulted in 100% mortality of the pest at higher conidial dose as compared to Qin-21 and Qin-18 which showing 80 and 64.64% mortality respectively. The LT50 was observed to be 3.63, 4.17 and 8.58 days in ME-33, Qin-21 and Qin-18, respectively at the highest conidial concentration (1x107ml-1 ). ME-33 isolate with the highest mortality and lowest LT50 at conidial concentration 1x107 ml-1 proved to be most effective for the control of S. oryzae. So these fungal islotes could be a better alternative for the management of S. oryzae

Time–dose–mortality data and modeling for the entomopathogenic fungus Aschersonia placenta against the whitefly Bemisia tabaci

2013 ◽  
Vol 59 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Junzhi Qiu ◽  
Feifei Song ◽  
Lihui Mao ◽  
Jie Tu ◽  
Xiong Guan
Keyword(s):  
Relative Humidity ◽  
Sweet Potato ◽  
Bemisia Tabaci ◽  
Entomopathogenic Fungus ◽  
Mortality Data ◽  
Tomato Plants ◽  
Mortality Models ◽  
Conidial Concentration ◽  
Sweet Potato Whitefly ◽  
Time Dose

The fungus Aschersonia placenta FJSM was evaluated for control of the sweet potato whitefly, Bemisia tabaci. Bemisia tabaci nymphs (1st–4th instars) on tomato plants in the greenhouse (25–27 °C, 70%–85% relative humidity) were sprayed with suspensions containing 0, 104, 105, 106, 107, or 108 A. placenta FJSM conidia/mL. Mortality of fungus-treated 1st to 3rd instar nymphs ranged from 93% to 100% but was <25% for 4th instar nymphs; the fungus sporulated from 70% to 80% of the fungus-treated B. tabaci cadavers. LD50 and LD90 values decreased with time after treatment and increased with instar. LT50 values decreased with conidial concentration. The data were then described with time–dose–mortality models. The results indicate that A. placenta FJSM has potential as a mycoinsecticide for control of B. tabaci.

scholarly journals Evaluation of the Potential of Fungal Biopesticides for the Biological Control of the Seed Bug, Elasmolomus pallens (Dallas) (Hemiptera: Rhyparochromidae)

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 277
Author(s):  
Fredrick Fidelis Umaru ◽  
Khanom Simarani
Keyword(s):  
Yield Loss ◽  
Insect Pest ◽  
Aspergillus Tamarii ◽  
Fungal Isolates ◽  
Synthetic Chemicals ◽  
Lethal Time ◽  
Conidial Concentration ◽  
Alternative Approaches ◽  
Fungal Biopesticides ◽  
Lc50 And Lc90

Elasmolomus pallens is a post-harvest insect pest of groundnuts which causes severe yield loss to farmers, particularly in Africa and Asia. Resistance to synthetic chemicals has been on the rise among insects and is a constraint on insecticides regulations. In view of the drive for alternative approaches to synthetic insecticides, this study evaluated the potential of biopesticides based on entomopathogenic fungi against E. pallens under laboratory conditions. Fungal isolates from the bug cadaver including Fusarium proliferatum F1, Aspergillus tamarii F2, A. flavus F3, Trichoderma atroviride F4, A. niger F4, and Metarhizium anisopliae (Meschn.) Sorokin, originating from the cadaver of Zonocerus variegatus were screened for virulence against the bug. Adult bugs were dipped briefly in conidial concentration 1 × 108 conidial mL−1 and observed at 25 ± 2 °C, 80 ± 10 RH and 14: 10 L:D for 10 days. The fungal isolates caused mortality ranging from 48 to 100% based on their potential to infect and kill the bug. Five conidial concentrations (1 × 104 to 1 × 108 conidia mL−1) were evaluated against adult bugs in the multiple-dose virulence bioassay. Lethal concentrations (LC50 and LC90) values of 6.75 × 106 and 4.42 × 109 conidia mL−1 were obtained for A. flavus F3 while M. anisopliae had 8.0 × 106 and 6.14 × 108 conidia mL−1 respectively. Lethal time (LT50 and LT90) values were 3.3 and 6.2 days for A. flavus F3 compared to 3.6 and 5.6 days for M. anisopliae, respectively. Thus, A. flavus F3 showed potential against E. pallens; and can be considered as an ideal isolate for incorporation into formulations for field applications.

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