scholarly journals Efficacy of different entomopathogenic fungal isolates against chilli aphid, Myzus Persicae (Sulz.)

2021 ◽  
Vol 23 (09) ◽  
pp. 241-247
Author(s):  
S. Sumaiya Parveen ◽  
◽  
R. Philip Sridhar ◽  
S. Usha Nandhini ◽  
◽  
...  

In recent years, microbial control of insect pests is becoming popular as insect pathogens such as bacteria, viruses, fungi and nematodes serve as potential bioagents in pest management. Among the different microbial agents, entomopathogenic fungi (EPF) are gaining importance in pest control. They can be easily mass cultured on artificial media without affecting their virulence at a cheaper cost. They are highly species specific with minimal impact on non-target organisms. The current study aimed to study the efficacy of entomopathogenic fungal isolates against aphid, Myzus Persicae (Sulz.) in chilli. Laboratory and field experiments were conducted to evaluate the pathogenicity of Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii against chilli aphid. From the study it is revealed that B. bassiana @ 108 spores ml-1 were found to be effective and found to be more superior to the other entomopathogenic fungal isolates viz., Metarhizium anisopliae and Lecanicillium lecanii against chilli aphid.

Author(s):  
Atef M M Sayed ◽  
Christopher A Dunlap

Abstract Six fungal isolates of Beauveria bassiana (Balsamo) Vuillemin and one isolate of Metarhizium anisopliae (Metschnikoff) Sorokin were isolated and evaluated for their pathogenicity to Icerya seychellarum (Westwood) and Aulacaspis tubercularis Newstead. There is a positive correlation between the concentration of the fungal blastospore concentrations and the percentage of mortality. Bio-efficacy increased significantly after inoculation with increasing concentration of blastospores and elapsed time up to 12 d after inoculation. The mortality of nymphs exposed to fungal isolates at various concentrations varied between 2.5 and 88.8%. Probit analysis of data at 95% confidence limits of LC50 and LT50s showed significant differences in the susceptibility of nymphs of I. seychellarum and A. tubercularis to the tested fungal isolates. The fungal isolates of Egy-6 and Egy-9 were the most effective against I. seychellarum and A. tubercularis, respectively. They had the lowest LC50 (4.20 × 105 and 5.71 × 103 blastospore ml−1) and LT50 (ranged from 4.61 to 9.79 and 4.84 to 8.71 d), respectively. The current study showed that all the fungal isolates yielded moderate mortality rates of nymphs and adult female populations of both the tested insect pests. To our knowledge, this is the first report of bio-efficacy of Beauveria and Metarhizium isolates against members of the Diaspidadae and Monophlebidae family insects. These results establish that the use of these native entomopathogenic fungi isolates of B. bassiana (Egy-3, Egy-4, Egy-6, Egy-7, Egy-9, and Egy-10) and M. anisopliae (Egy-5) could be considered for further development as microbial control agents of the mealybug and scale insects as a potential biological agent for use in an IPM program.


2018 ◽  
Vol 19 (6) ◽  
pp. 2365-2373 ◽  
Author(s):  
AYU SAFITRI ◽  
SITI HERLINDA ◽  
ARUM SETIAWAN

Safitri A, Herlinda S, Setiawan A. 2018. Entomopathogenic fungi of soils of freshwater swamps, tidal lowlands, peatlands, and highlands of South Sumatra, Indonesia. Biodiversitas 19: 2365-2373. Ecosystems of lowlands and highlands in South Sumatra have specific characteristics of soils and vegetations that can affect the availability of entomopathogenic fungi. This study aimed to explore and identify species and to determine inoculum potentials of the entomopathogenic fungi from soils of freshwater swamps, tidal lowlands, peatlands, and highlands. Baiting of entomopathogenic fungi on soil samples used the larvae of Tenebrio molitor. The entomopathogenic fungi species found in this research were Beauveria bassiana and Metarhizium anisopliae. The number of the fungal isolates were 30 isolates consisting of nine isolates of B. bassiana and 21 isolates of M. anisopliae.The highest number of isolates was found in the highland ecosystem (11 isolates) and the lowest was found in peatland ecosystem (4 isolates). The highest percentage average of inoculum potentials of the fungi was found in the high land ecosystem (4.04%) and the lowest one was found in freshwater swamps ecosystem (2.11%). Based on the vegetation type, the soil planted with mustard in Talang Patai-Pagaralam (highland ecosystem) had the highest inoculum potentials (9.33%). These fungi will make an important contribution to the biological control for insect pests in lowland to highland ecosystems in Indonesia.


2008 ◽  
Vol 75 (4) ◽  
pp. 491-498
Author(s):  
E.S. Loureiro ◽  
A. Moino Júnior

RESUMO As espécies de pulgões Aphis gossypii e Myzus persicae são cosmopolitas e polífagas, causando prejuízos em plantas cultivadas. Foi avaliado o consumo de A.gossypii e M. persicae, infectados com fungos entomopatogênicos por Orius insidiosus. No centro de placas de Petri foi colocado um disco de 4,5 cm de diâmetro de folha de algodão (para A. gossypii) e um disco de 4,5 cm de diâmetro de folha de pimentão (para M. persicae). A inoculação dos fungos (Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea e Lecanicillium lecanii) foi feita através da adição de 1 mL das suspensões fúngicas 1,0 x 105 e 1,0 x 107 conídios/mL sobre a placa de Petri. Os pulgões foram oferecidos a uma fêmea do predador, liberada na placa em diferentes períodos de tempo após a inoculação, além de um tratamento no qual a fêmea do predador foi liberada com os pulgões mortos, já em fase de conidiogênese. As fêmeas do predador foram retiradas após 24 horas da liberação e, em seguida, foi avaliado o consumo de pulgões. O consumo foi significativamente inferior decorridas 24 horas da inoculação, quando comparado com o a testemunha, para as duas espécies de pulgões estudadas. O consumo de pulgões foi menor nas concentrações testadas no período de 24-48 horas que o consumo da testemunha. Após 72 horas da inoculação e após conidiogênese, não foi observado consumo de pulgões pelo predador para as duas concentrações, evidenciando, dessa forma, a capacidade discriminatória do predador, sendo capaz de reconhecer a presa infectada pelo patógeno.


2018 ◽  
Vol 17 ◽  
pp. 82-91 ◽  
Author(s):  
Dipak Khanal

Soil insect pests are the major productivity constrains of different crops among which white grubs (Coleoptera: Scarabaeidae), both adult and larval stages, are extremely destructive in nature. Laboratory studies were conducted to evaluate the virulence of an indigenous and a commercial strain of the entomopathogenic fungi, Metarhizium anisopliae (Metsch.) Sorokin, against white grubs species Chiloloba acuta by applying the dipping method at Entomology Division, NARC, Nepal. Third instars larvae of C. acuta were dipped in suspensions of indigenous and commercial strains (Pacer) of M. anisopliae at different concentrations ranging from 3.33×104 to 1.04×108 spores/ml for 3-5 seconds which resulted in 97.8% and 89% mortalities with the highest dose of 1.04×108 spores/ml 40 days after inoculation (DAI), respectively. The LC50 values for indigenous and commercial strain were 3.5×105 and 1.88×106 spores/ml, respectively, with the potency of 1:0.28 at 40 DAI. Bioassays were conducted in completely randomized design. From results it is concluded that the tested strains of entomopathogenic fungi have potential as microbial control agents in managing white grubs in laboratory and it is suggested to be tested under farmers field condition.


2021 ◽  
pp. 1-15
Author(s):  
Mouna Kahia ◽  
Thi Thuy An Nguyen ◽  
Frédéric McCune ◽  
Rémi Naasz ◽  
Hani Antoun ◽  
...  

Abstract The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control.


Agronomy ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 7 ◽  
Author(s):  
Talha Nazir ◽  
Abdul Basit ◽  
Abdul Hanan ◽  
Muhammad Majeed ◽  
Dewen Qiu

Green peach aphid, Myzus persicae (Hemiptera: Aphididae), is an economically important pest of crops within more than 40 plant families all over the world. This study encompasses in-vitro pathogenicity of two strains of Beauveria bassiana (BB-72 and BB-252) and one strain of Lecanicillium lecanii (V-4) against green peach aphid (M. persicae). Using a leaf-dip method, three different bioassays were conducted comprised of filtrates and conidial concentrations of BB-72, BB-252 and V-4 fungal strains and their binary combinations. Infiltrate bioassays, 2 mL fungal filtrate of each strain was used. In conidial bioassays, three different concentrations (i.e., 1 × 106, 1 × 107 and 1 × 108 conidia mL−1) of each fungal strain were used, while in binary combination bioassays, LC50 and LC33 of these fungal strains were evaluated. According to the results, maximum pathogenicity against test aphids was observed at 10th day of all treatments. Both strains of B. bassiana (BB-72 and BB-252) exhibited higher mortality of aphids (up to 95 and 91%, respectively) than L. lecanii (V-4) strain (87%) in all three types of bioassays. Moreover, binary combinations of BB-72 and BB-252 strains showed significantly higher aphid mortality (94%) than other combinations. Reduced mortality in case of fungal combinations of V-4 strain might be due to the antagonistic effect of L. lecanii strain along with both strains of B. bassiana. Nevertheless, evaluation of combined pathogenicity of the fungal strains constitutes the novelty of this in-vitro study which revealed that both strains of B. bassiana (i.e., BB-72 and BB-252) are mutually compatible and can be utilized together as new biocontrol tools against destructive insect pests such as M. persicae.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1269
Author(s):  
David K. Mfuti ◽  
Amanuel Tamiru ◽  
William D. J. Kirk ◽  
Adeyemi O. Akinyemi ◽  
Heather Campbell ◽  
...  

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.


2021 ◽  
Vol 3 (2) ◽  
pp. 383-393
Author(s):  
Patient Farsia Djidjonri ◽  
Nukenine Elias Nchiwan ◽  
Hartmut Koehler

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.


Behaviour ◽  
1981 ◽  
Vol 76 (3-4) ◽  
pp. 223-249 ◽  
Author(s):  
Douglas G. Richards

AbstractIn numerous species of passerine birds the initial few notes of the song have a narrow frequency range and wide temporal spacing when compared with the rest of the song. This structure is well adapted for high detectability when the song is acoustically degraded during passage through the environment. The song of the rufous-sided towhee (Pipilo eythrophtalmus) consists of relatively tonal introductory syllables followed by a complex rapid trill. The trill is capable of carrying more information than the introduction, but is inherently less detectable at a distance owing to degradation by reverberation, amplitude fluctuation, and frequency-dependent attenuation. Signal detection theory predicts that the detectability of the trill will be increased when it is preceded by the introductory syllables, owing to the removal of uncertainty concerning the time of arrival of the signal. This is alerted detection. I performed field experiments using playback of recorded song to towhees to test the hypothesis that these introductory syllables facilitate detection of conspecific song at a distance. Tape recordings of normal and artificially degraded full songs, introduction, and trills were played to territorial male towhees. Normal songs, degraded songs, and normal trills elicited strong territorial defense responses, indicating recognition as adequate species-specific song, and confirming that sufficient information is contained in the trill for species recognition. Degraded trills alone elicited little response. Both normal and degraded introductions also elicited little response, demonstrating that the increased response to a degraded full song over that to a degraded trill is not due to any species-specific characteristics of the introduction, but rather to its function as an alerting stimulus.


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