scholarly journals Interactions Between Two Invertebrate Pathogens: An Endophytic Fungus and an Externally Applied Bacterium

2020 ◽  
Vol 11 ◽  
Author(s):  
Waqas Wakil ◽  
Muhammad Tahir ◽  
Abdullah M. Al-Sadi ◽  
David Shapiro-Ilan

The members of family Noctuidae exist in diverse environments and many species from this group are of agriculture importance, particularly Helicoverpa spp. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a major pest of many legumes and cereal crops. Due to environmental and regulatory concerns, safe alternatives to broad spectrum chemical insecticides are needed for the control of key noctuid pests such as H. armigera. A strain of Beauveria bassiana (Cordycipitaceae: Hypocreales) was evaluated for its ability to colonize endophytically in chickpea plants, and its effectiveness against second (L2) and fourth (L4) larval instars of H. armigera. B. bassiana was inoculated to chickpea plants through injection and endophytic establishment was confirmed by re-isolating the fungi from leaf samples. A detached leaf assay was used to evaluate pathogenicity. Bacillus thuringiensis was also applied to both larval stages through leaf dip method. In a novel approach, combined treatments of bacteria and endophytic fungi were compared with single-pathogen treatments. Relative to the single treatments, the combined pathogen treatments exhibited an increase in larval mortality, and decrease in pupation, adult emergence and egg eclosion. Specifically, synergistic effects on mortality were observed when larvae were exposed to simultaneous application of B. bassiana (1 × 108 conidia ml–1) with B. thuringiensis (0.75 μg ml−1). Both instars exhibited varying level of growth, development, frass production, diet consumption and fecundity when exposed to the chickpea leaves inoculated with endophytic B. bassiana and dipped with sub-lethal doses of B. thuringiensis. These findings indicate that the integrated application of endophytic colonized B. bassiana and B. thuringiensis can be effectively used against H. armigera.

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ghulam Sarwar ◽  
Naeem Arshad Maan ◽  
Muhammad Ahsin Ayub ◽  
Muhammad Rafiq Shahid ◽  
Mubasher Ahmad Malik ◽  
...  

Abstract Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.


Author(s):  
Eman Mohammed Abd-ElAzeem ◽  
Warda Ahmed Zaki El-Medany ◽  
Hend Mohammed Sabry

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.


2019 ◽  
Vol 11 ◽  
pp. 117954331986711 ◽  
Author(s):  
Muhammad Irfan Ullah ◽  
Nimra Altaf ◽  
Muhammad Afzal ◽  
Muhammad Arshad ◽  
Naunain Mehmood ◽  
...  

Entomopathogenic fungi (EPFs), Isaria fumosorosea and Beauveria bassiana, are efficient biological agents in the management of multiple arthropod pests. In this study, the effects of both EPF species on various life stages of Spodoptera litura (F.) (Lepidoptera: Noctuidae) and its natural enemy Rhynocoris marginatus (Fab.) (Hemiptera: Reduviidae) were determined under laboratory conditions. I. fumosorosea significantly ( P < .05) reduced the growth rate of the third and fourth instar larvae of S. litura. For relative consumption rate (RCR), the maximum impact was recorded for I. fumosorosea, which reduced the RCR of the larvae. The larvae of S. litura treated with I. fumosorosea showed significantly lower efficiency of conversion of ingested food (ECI) and the larval mortality rate (58.0%) was also higher compared with B. bassiana (33.3%). Similarly, I. fumosorosea had a significant effect on the pupal formation of S. litura; however, no significant effect was found on adult emergence percentage. To determine the effect of EPF-infected prey on the adult predator, their handling time, predatory rate, consumption rate, and the survival rate were recorded. No significant effect of EPF species on the predation rate was found. Furthermore, no significant difference was found in the survival rate of predators fed on either EPF-infected prey or healthy larvae. The interaction of these EPFs with a reduviid predator suggested that both EPF species, especially I. fumosorosea, could be used together with the predator to boost the biological control of S. litura in commercial crops.


2019 ◽  
Vol 112 (5) ◽  
pp. 2369-2380 ◽  
Author(s):  
Jing Zhang ◽  
Xiaoxia Liu ◽  
Yichen Liu ◽  
Yueqing An ◽  
Haibo Fang ◽  
...  

AbstractMethoprene-tolerant (Met) is a putative JH intracellular receptor that transduces JH signal by activation of the inducible Krüppel homolog 1 (Kr-h1). We analyzed the gene sequences of Met and Kr-h1 and their patterns of expression in Grapholita molesta (Busck) immature and adult stages in order to better understand the roles of these primary JH responders in regulating the metamorphosis and reproduction of this global pest of fruit crops. The deduced amino acid sequences of both GmMet and GmKr-h1 were highly homologous to those of other Lepidoptera, especially the cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae). Peak expression of GmMet occurred during the last 3 to 5 d of the final instar, followed by that of GmKr-h1, in the last 3 d of final instar. Similar patterns of GmMet and GmKr-h1 expression were detected across various tissue types in the fifth-instar larvae, with the highest expression observed in the head, followed by the epidermis, and the fat body. When expression of GmMet and GmKr-h1 was knocked down via dsRNA injection in the fifth instar, the results were increased larval mortality, abnormal pupation, delayed pupal duration, reduced adult emergence, extended preoviposition period, and reduced fecundity. We infer that both GmMet and GmKr-h1 participated in regulation of metamorphosis and reproduction in G. molesta, the former acting upstream of the latter, and could present biorational targets for novel pest control compounds.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhay Punia ◽  
Nalini Singh Chauhan ◽  
Drishtant Singh ◽  
Anup Kumar Kesavan ◽  
Sanehdeep Kaur ◽  
...  

AbstractThe antibiosis effect of gallic acid on Spodoptera litura F. (Lepidoptera: Noctuidae) and its parasitoid evaluated by feeding six days old larvae on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm, 3125 ppm) of the phenolic compound revealed higher concentration (LC50) of gallic acid had a negative impact on the survival and physiology of S. litura and its parasitoid Bracon hebetor (Say) (Hymenoptera:Braconidae). The mortality of S. litura larvae was increased whereas adult emergence declined with increasing concentration of gallic acid. The developmental period was delayed significantly and all the nutritional indices were reduced significantly with increase in concentration. Higher concentration (LC50) of gallic acid adversely affected egg hatching, larval mortality, adult emergence and total development period of B. hebetor. At lower concentration (LC30) the effect on B. hebetor adults and larvae was non-significant with respect to control. Gene expression for the enzymes viz., Superoxide dismutase, Glutathione peroxidase, Peroxidase, Esterases and Glutathione S transferases increased while the total hemocyte count of S. litura larvae decreased with treatment. Our findings suggest that gallic acid even at lower concentration (LC30) can impair the growth of S. litura larvae without causing any significant harm to its parasitoid B. hebetor and has immense potential to be used as biopesticides.


3 Biotech ◽  
2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Domenico Rizzo ◽  
Nicola Luchi ◽  
Daniele Da Lio ◽  
Linda Bartolini ◽  
Francesco Nugnes ◽  
...  

AbstractThe red-necked longhorn beetle Aromia bungii (Faldermann, 1835) (Coleoptera: Cerambycidae) is native to east Asia, where it is a major pest of cultivated and ornamental species of the genus Prunus. Morphological or molecular discrimination of adults or larval specimens is required to identify this invasive wood borer. However, recovering larval stages of the pest from trunks and branches causes extensive damage to plants and is timewasting. An alternative approach consists in applying non-invasive molecular diagnostic tools to biological traces (i.e., fecal pellets, frass). In this way, infestations in host plants can be detected without destructive methods. This paper presents a protocol based on both real-time and visual loop-mediated isothermal amplification (LAMP), using DNA of A. bungii extracted from fecal particles in larval frass. Laboratory validations demonstrated the robustness of the protocols adopted and their reliability was confirmed performing an inter-lab blind panel. The LAMP assay and the qPCR SYBR Green method using the F3/B3 LAMP external primers were equally sensitive, and both were more sensitive than the conventional PCR (sensitivity > 103 to the same starting matrix). The visual LAMP protocol, due to the relatively easy performance of the method, could be a useful tool to apply in rapid monitoring of A. bungii and in the management of its outbreaks.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Gurmehar Kaur Grewal ◽  
Neelam Joshi ◽  
Yadhu Suneja

Abstract Background Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) is a serious agricultural pest that infests many commercially important crops of Southeast Asian countries. Indiscriminate use of chemical pesticides has led to various health hazards as well as insecticide resistance. Entomopathogenic fungi (EPF) provide an important alternative as biological control agents. Metarhizium rileyi is an EPF with a specific host range for lepidopteran pests. The present study aimed to identify virulent M. rileyi isolate against S. litura larvae and analyse their extracellular cuticle-degrading enzyme activities. Results Three M. rileyi isolates viz M. rileyi NIPHM, M. rileyi MTCC 4254 and M. rileyi MTCC 10395 formulations were evaluated at different concentrations against 2nd instar larvae of S. litura. A maximum percent mortality of 63.33% was recorded in M. rileyi NIPHM (12 g/l), followed by M. rileyi MTCC 4254 (58.33%) at the same concentration, 10 days post-treatment. Maximum means of chitinase, protease and lipase activities (0.44, 1.58 and 2.95 U/ml, respectively) were recorded in the case of M. rileyi NIPHM. Correlation analysis was positive between enzyme activity and larval mortality. Conclusions Metarhizium rileyi NIPHM recorded the highest enzymatic activity and exhibited the maximum mortality rate against 2nd instar larvae of S. litura, suggesting the possible role of these enzymes in the pathogenicity of the fungus. Further knowledge in this regard may help in the development of enzyme-based screening methods for selecting virulent fungal isolates for the eco-friendly management of crop pests.


Author(s):  
Mervat A. Kandil ◽  
Hemat Z. Moustafa

Abstract Background Cotton bollworms such as Pectinophora gossypiella and Earias insulana are serious pests which destroy the cotton plant, and Bracon brevicornis is a parasitoid which attacked the larvae of bollworms. Results In this study, experiments were performed to investigate and evaluate the toxicity of etofenprox and chlorpyrifos insecticides against newly hatched larvae of Pectinophora gossypiella and Earias insulana. Some biological aspects of compound effects on larval and pupal duration, percentage of mortality, and percentage of adult emergence which resulted from treated newly hatched larvae were studied. The results revealed that LC50 was 0.7 and 0.87 ppm when P. gossypiella was treated with etofenprox and chlorpyrifos, respectively, while LC50 was 0.09 and 0.73 ppm when E. insulana was treated with etofenprox and chlorpyrifos, respectively. The obtained results showed that the percentage of mean larval mortality was 65.0 and 63.0% for treated P. gossypiella, while it was 71.0 and 66.0% for treated E. insulana. The corresponding figure for pupal percentage mortality was 8.0 and 10.0% for treated P. gossypiella, but it was 5.0 and 2.0% for treated E. insulana, with etofenprox and chlorpyrifos, and a prolongation effect in larval and pupal development (total immature stage) resulted from treated both bollworms as follows: 35.5 and 32.4 days for treated P. gossypiella compared with 21.9 days in control and 34.7 and 23.2 days for treated E. insulana compared with 23.1 days in control. The indirect effect of etofenprox and chlorpyrifos on the total immature stage of Bracon brevicornis was 18.2 and 19.5 days compared with 14.3 days in control when B. brevicornis parasitized on P. gossypiella larvae while it was 19.8 and 20.6 days compared with 15.2 days when B. brevicornis parasitized on E. insulana larvae. Conclusion The life cycle of B. brevicornis after parasitism on P. gossypiella and E. insulana larvae treated with etofenprox and chlorpyrifos were increased than the control larvae.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1886
Author(s):  
Abdourahamane Issa M. Nourou ◽  
Addam Kiari Saidou ◽  
Jens B. Aune

Sowing and application of mineral and organic fertilizer is generally done manually in the Sahel, resulting in low precision and delayed application. The objective of this paper is to present a new mechanical planter (Gangaria) for the combined application of seeds and soil amendments (mineral fertilizer, compost, etc.), and to assess the effects of using this planter in pearl millet on labor use, yield and economic return. The labor study showed that the mechanized application of seeds and compost reduced time use by a factor of more than six. The on-station experiments were completely randomized experiments with six replications and six treatments: T0 (control), T1 (0.3 g NPK hill−1), T2 (25 g compost hill−1), T3 (25 g compost + 0.3 g NPK hill−1), T4 (50 g compost hill−1) and T5 (50 g compost + 0.3 g NPK hill−1). Treatments T1 to T5 were sown by the planter with seeds that were primed in combination with coating of seeds with a fungicide/insecticide. The treatment T5 increased grain yield and economic return compared to the control by 113% and 106%, respectively. The advantages for farmers using this approach of agricultural intensification are timelier sowing of dryland cereal crops, easy application of organic fertilizer and more precise delivery of input, thereby making this cropping system more productive and less vulnerable to drought.


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