scholarly journals Efficacy of the entomopathogenic nematode isolate Heterorhabditis taysearae to control the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Amany M. Abd El Azim
Keyword(s):  
Spodoptera Littoralis ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Entomopathogenic Nematode ◽  
Control Agent ◽  
Local Alignment ◽  
Cotton Leaf ◽  
Internal Transcribed Spacer Region ◽  
Control Programs ◽  
Lepidoptera Noctuidae

Abstract Background Entomopathogenic nematodes (EPNs) are promising alternatives since they have many characteristics as a biological control agent against insect pests. Results Among indigenous EPN isolated, adapted to local environmental conditions by employing the Galleria baiting strategy, only one sample was positive for the presence of EPNs. The new isolate was identified at the species level using DNA sequencing of the internal transcribed spacer region and the Basic Local Alignment Search Tool search of GenBank showed that the isolate had a high similarity (99%) with that sequence available for Heterorhabditis taysearae. The pathogenicity of the EPN isolate was tested against the cotton leaf worm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), using different concentrations (60, 90, 120 and 150 IJs/larvae). Data showed that 150 IJs/larvae caused 100% mortality rate, followed by 120 IJs/larvae (90%), while 60 IJs/larvae showed the lowest rate (60%) after 72 h. Conclusions The present study indicated that the native isolate of EPN could be recommended against S. littoralis as an efficient tool in its control programs.

scholarly journals Pathogenicity of some local entomopathogenic fungus isolates on the cotton leafworm larvae, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Funda Şahin ◽  
Yusuf Yanar
Keyword(s):  
Biological Control ◽  
Entomopathogenic Fungi ◽  
Entomopathogenic Fungus ◽  
Spodoptera Littoralis ◽  
Biological Control Agent ◽  
Mortality Rates ◽  
Control Agent ◽  
Soil Samples ◽  
Cotton Leaf ◽  
Lepidoptera Noctuidae

Abstract Background Pathogenicity of the entomopathogenic fungi (EPF), isolated from soil samples collected from Ordu Province, Turkey, was evaluated on the second-instar larvae of the cotton leaf worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) under laboratory conditions. Results Firstly, single-concentration response tests were conducted in order to determine the efficacy of the 64 isolates on S. littoralis larvae at the concentration of 1 × 108 conidia/ml. The five isolates displaying the highest mortality rates in single-concentration response tests, ORU-50, ORM-40, ORP-13, ORP-27 and ORM-48 (which included Beauveria bassiana, Metarhizium brunneum and Clonostachys rogersoniana), were subjected to concentration–response tests at the concentrations of 1 × 105–1 × 109 conidia/ml. The lowest LC50 and LC90 values were recorded at ORP-27 with 1.68 × 107 and 4.60 × 108 conidia/ml, respectively, followed by ORP-13 and ORM-40. Conclusions Accordingly, it was found that M. brunneum isolates were more effective than B. bassiana and C. rogersoniana against S. littoralis larvae. ORP-27, ORP-13 and ORM-40 of M. brunneum isolates can be a potential biological control agent used against S. littoralis larvae.

scholarly journals Efficacy of the parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) on the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) egg masses

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Hend O. Mohamed
Keyword(s):  
Spodoptera Littoralis ◽  
Insect Pests ◽  
Single Layer ◽  
Control Agent ◽  
Physical Characteristics ◽  
Great Ability ◽  
Egg Masses ◽  
Cotton Leafworm ◽  
Lepidoptera Noctuidae ◽  
Trichogrammatoidea Bactrae

Abstract Background The Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is one of the major insect pests, causing a significant damage on different cultivated agricultural crops. Developing an alternative non-chemical tool, an effective and environmentally friendly method to suppress pest's infestation is essentially needed. Therefore, biological control by releasing the egg parasitoids could be the most promising tool for integrated pest management. Results This study was designed to evaluate the efficacy of the egg parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) as a bio-control agent against S. littoralis egg masses with different physical characteristics (number of egg layer and degree of scale density) in a no-choice and choice tests, under laboratory conditions. Also, the parasitoids’ fitness in terms of parasitism percentage, developmental period, adults’ emergence percentage, female offspring percentage, and longevity were investigated. The results revealed that T. bactrae wasps had a great ability to parasitize S. littoralis egg masses, but with different rates, related to their layers and scales’ thickness in both tests. The highest parasitism percentage was observed on one-layer eggs, followed by two layers. However, 3-layer eggs were the least preferable one. High numbers of adult emergencies (> 80%) were observed in all tested egg masses, except in the case of 3 layers with high scales. Furthermore, female-biased sex ratios were noticed at all examined eggs, with only the exception of high-scaly eggs with a single layer that recorded the lowest rate (≤ 45%). Besides, the survival of adult female parasitoids was not significantly affected in both tests. Conclusions T. bactrae could be used as a bio-control agent against S. littoralis egg masses with different physical characteristics based on the achieved results.

scholarly journals Morpho-taxometrical and molecular characterization of Steinernema abbasi (Nematoda: Steinernematidae) and its pathogenicity and generative potential against lepidopteran pests

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Heena ◽  
Aasha Rana ◽  
Aashaq Hussain Bhat ◽  
Ashok Kumar Chaubey
Keyword(s):  
Galleria Mellonella ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Virulent Strain ◽  
Entomopathogenic Nematode ◽  
Uttar Pradesh ◽  
Original Description ◽  
Control Agent ◽  
Lepidopteran Insect ◽  
Highly Virulent

Abstract Background An entomopathogenic nematode (EPN) was recovered by using Galleria baiting technique from the soils of marigold fields of Noida, Uttar Pradesh, India. Based on morphological, morphometrical and molecular characterizations, the isolated strain was identified as Steinernema abbasi and tagged as CS38. The isolated strain was conspecific to original description with minor deviations. Infective juveniles (IJs) of present strain were longer than original description. Results Molecular analysis was done using ITS1-5.8S-ITS2 and D2D3 regions. Pathogenicity and generative potential of the present strain CS38 were tested against larvae of 3 lepidopteran insect pests, namely, Galleria mellonella L., Helicoverpa armigera (Hb.) and Spodoptera litura (Fab.). Different concentrations of IJs/larva, viz. 25, 50, 100, and 200 IJs/larva, were used for bioassay trails. All experiments were repeated thrice to reach the optimum authenticity. Results of bioassays revealed that isolate CS38 was highly virulent against the 3 insect pests and caused (100%) mortality within 48 h under laboratory conditions. Generative potential of the studied S. abbasi CS38 was recorded high in G. mellonella (19 × 104 IJs/larva) at 100 IJs/larva concentration, followed by H. armigera (63.4 × 103 IJs/larva) and S. litura (60.5 × 103 IJs/larva). Conclusions Isolate CS38 is an indigenous, dominant and highly virulent strain that can be utilized as a biological control agent against the three studied insects. Moreover, it can be used for commercialization of the production of EPN-based biopesticide to be added under Integrated Pest Management in Indian agriculture system.

scholarly journals Alterations in the expression of certain midgut genes of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) larvae and midgut histopathology in response to Bacillus thuringiensis Cry1C toxin

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Hager Khalil ◽  
Saad Moussa ◽  
Haggag S. Zein ◽  
Dalia S. Ahmed ◽  
El-Sayed H. Shaurub ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Littoralis ◽  
Biological Control Agent ◽  
Mrna Level ◽  
Regulatory Elements ◽  
Control Agent ◽  
Peritrophic Membrane ◽  
Cotton Leaf ◽  
Pest Species ◽  
Tolerant Strain

Abstract Background Bacillus thuringiensis (Bt) utilization as a biological control agent is highly recommended due to its safety, specificity, and efficiency. Importance of the entomocidal Cry proteins secreted by Bt is dramatically increased subsequent Cry genes transformation into a number of economic crops, rendering them protection against insect attack. In the last decade, insect resistance against transgenic Bt crops is gradually raised in several lepidopteran pests. A better understanding of the processing of Bt Cry1C toxin in the larval midgut of the lepidopteran pest species, the cotton leaf worm, Spodoptera littoralis (Boisd.), is very important to characterize the main regulatory elements of Bt tolerance. Results The present study aimed to define factors that are involved in insect tolerance toward Bt Cry1C through evaluating the mRNA level of trypsin (Try), aminopeptidase N (APN), alkaline phosphatase (ALP), cadherin (Cad), and cytochrome P450 (CYP) in both susceptible and cry1C tolerant strains of S. littoralis. Total RNAs were extracted from susceptible and tolerant strains to construct cDNAs. Quantitative real-time polymerase chain reaction (qPCR) showed a significant upregulation of CYP gene in tolerant strain. In contrast, the levels of expression of Try, ALP, and Cad were significantly downregulated in tolerant strain. APN relative mRNA expression did not show significant differences between susceptible and tolerant strains. Histologically, the midgut of late third-instar larvae of tolerant population S. littoralis showed vacuolization of the epithelium and disruption of both the peritrophic membrane and the striated boarder compared to the susceptible strain. Conclusions Obtained data indicated a relationship between exposing to Bt Cry1C toxin and alteration of CYP, Try, ALP, and Cad expression in midgut of S. littoralis. These results may be an evidence for the important roles of CYP, Try, ALP, and Cad in the resistance development and toxicity to Bt Cry1C. The results are useful for further illustrating of Bt Cry1C processing and S. littoralis tolerance.

scholarly journals Efficacy of the entomopathogenic nematode isolates against Spodoptera littoralis (Boisduval) and Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Gehan Mohamed Nouh
Keyword(s):  
Spodoptera Littoralis ◽  
Galleria Mellonella ◽  
Insect Pests ◽  
Entomopathogenic Nematode ◽  
Insect Pest ◽  
Soil Samples ◽  
Agrotis Ipsilon ◽  
Pest Species ◽  
Egyptian Clover ◽  
Lepidoptera Noctuidae

Abstract Background Entomopathogenic nematodes (EPNs), as biological control agents, have been isolated from many regions throughout the world. Local isolates of EPNs are usually more effective for controlling indigenous insect pests as they are adapted to the local environmental conditions and the insect pest species. Results In the present work, EPN isolates were searched in the soil under citrus and guava trees, and Egyptian clover at Noubaria region, Elbhaira governorate, Egypt, within two consecutive years. The EPNs were isolated from two positive soil samples of Egyptian clover (Trifolium alexandrinum) (TAN5) and guava trees (Psidium guajava) (PGN6), while the EPNs were not existent in the soil samples under citrus. Laboratory applications of the two EPNs isolates against the cotton leafworm, Spodoptera littoralis(Boisd.), and the black cutworm, Agrotis ipsilon (Hufn.) (Lepidoptera: Noctuidae), were recorded. Nematodes naturally occurring in the soil were trapped by full-grown larvae of the greater wax moth (Galleria mellonella L.). Infected larvae turned from whitish beige to dark reddish color, proofed that these isolates belong to the genus Heterorhabditis. Laboratory results revealed that the mortality rate ranges from 24 to 100% with TAN5 while from 18 to 96% with PGN6 at A. ipsilon larvae. The LC50 values of TAN5 against A. ipsilon were 1285.527 and 1560.747 IJs/cup, while those values for S. littoralis were 1339.099 and 2531.605 IJs/cup in larvae and pupae, respectively. The 3rd instar larvae of A. ipsilon and S. littoralis were more sensitive than the pupae. Production of Heterorhabditis sp. strain TAN5 was the highest in the reproduction of infective juveniles than the strain PGN6 at all concentrations. Conclusions The EPNs isolated from the soil samples belonged to the genus Heterorhabditis. Heterorhabditis sp. strain (TAN5) collected from the soil under Egyptian clover at Noubaria region was the highest reproduction and the most effective against both tested pests, A. ipsilon and S. littoralis larvae and pupae. EPN species would serve as an alternative to chemical pesticides and fit well in an integrated pest management program against larvae as well as adults and pupae of many economic insect pests which inhabit the soil.

scholarly journals Could Gnomoniopsis castaneae Be Used as a Biological Control Agent against Insect Pests?

2021 ◽  
Vol 11 (9) ◽  
pp. 4066
Author(s):  
Spiridon Mantzoukas ◽  
Ioannis Lagogiannis ◽  
Aristeidis Ntoukas ◽  
George T. Tziros ◽  
Konstantinos Poulas ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Brown Rot ◽  
Control Agent ◽  
Effective Control ◽  
Mortality Factor ◽  
Perennial Crop ◽  
Gall Wasp ◽  
Pathogenic Potential

Gnomoniopsis castaneae is the cause of the chestnut brown rot but has been also regarded as an important mortality factor for the chestnut gall wasp Dryocosmus kuriphilus. The question to whether G. castaneae could serve as a natural biocontrol agent against insect pests is investigated in the present study. We used three serious insect pests as experimental model insects: Plodia interpuctella and Trogoderma granarium, which are important pests of stored products, and Myzus persicae, a cosmopolitan, serious pest of annual and perennial crop plants. Although chemical pesticides represent effective control means, they are also related to several environmental and health risks. In search for alternative pest management methods, scientific interest has been focused, inter alia, on the use of entomopathogenic fungi. While Isaria fumosorosea has long been recognized as an effective control agent against several pests, G.castaneae has been very little studied. The present study examined whether and to what extent G. castaneae and I. fumosorosea exhibit insecticidal activity against fourth-instar larvae of P. interpunctella and T. granarium and adults of M. persicae. Mortality was examined in interrelation with dosage and time exposure intervals. Both fungi exhibited pesticidal action. However, G. castaneae induced noteworthy mortality only at very high doses. In general, we concluded that G. castaneae failed to cause high insect pathogenicity at normal doses and may not be an efficient biocontrol agent compared with other entomopathogens. On the other hand, our study reiterates the pathogenic potential of I. fumosorosea. More studies are needed to further our insight into the potential of EF species as a component of IPM.

scholarly journals Evaluation of cellulose substrates treated with Metarhizium anisopliae (Metschnikoff) Sorokin as a biological control agent against the termite Microcerotermes diversus Silvestri (Isoptera: Termitidae)

2011 ◽  
Vol 43 (2) ◽  
pp. 269
Author(s):  
Behzad Habibpour ◽  
Amir Cheraghi ◽  
Mohammad Saeed Mossadegh
Keyword(s):  
Biological Control ◽  
Metarhizium Anisopliae ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Control Agent ◽  
Cellulose Substrates ◽  
Virulent Strains ◽  
Sustainable Protection ◽  
Chemical Pesticides

This article is the first report on the promising effect of an entomopathogenic fungus, <em>Metarhizium anisopliae</em> (Metschnikoff) Sorokin to control populations of <em>Microcerotermes diversus </em>Silvestri. Biological control is an alternative to the long-term usage of chemical pesticides.<em> M. anisopliae</em>, the causal agent of green muscardine disease of insects, is an important fungus in biological control of insect pests. Bait systems can eliminate entire colonies of subterranean termites. Baiting reduces adverse environmental impacts caused by organochlorine and organophosphate pesticides in the control of termites and creates sustainable protection of buildings against their invasion. Treated-sawdust bait was applied by two methods: a) combination of treated sawdust and untreated filter paper, and b) combination of treated sawdust and untreated sawdust. When combinations of treated sawdust and untreated sawdust were used, LC50 and LC90 were 8.4&times;106 and 3.9&times;107 (spore/ml), respectively. With the use of improved bait formula and more virulent strains, we hope to achieve better control of termite colonies and enable pathogens to become a useful element in the Integrated Pest Management system.

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