scholarly journals Impact of insecticides on the efficacy of entomopathogenic nematodes against the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) on cabbage in northern Benin

2019 ◽  
Author(s):  
Brice G. Sinhouenon ◽  
Hugues Baimey ◽  
Laura Wauters ◽  
Rufin Dossou ◽  
Regis B. Ahissou ◽  
...  
Keyword(s):  
Survival Rate ◽  
Plutella Xylostella ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Neem Oil ◽  
Nematode Reproduction ◽  
The Subject ◽  
The Impact

Description of the subject. The article deals with the study of compatibility of entomopathogenic nematode (EPN) species with insecticides currently used against diamondback moth (DBM) Plutella xylostella (L.) in northern Benin Objectives. The aim of this work was to determine the impact of five insecticides on the efficacy of entomopathogenic nematodes against DBM larvae. Method. Infective juveniles (IJs) of two EPN species (Steinernema sp. 83a and Heterorhabditis sonorensis KF723827) were exposed to five insecticides used against P. xylostella larvae in Djougou for 48 h. The number of surviving nematodes was used to infest DBM larvae. The experiment was carried out under laboratory and semi-field conditions. Results. The bioassays carried out in laboratory showed that the survival rate of nematodes exposed to KARATE 2.5 WG, LAMBDA SUPER 2.5EC or neem oil ranges between 95% and 98%. In the treated plots, Steinernema sp. 83a was the most virulent with the highest P. xylostella mortality (87% at 50 IJs·cm-2 after 24 h) while only 35% larval mortality was recorded for H. sonorensis applied at the same dose. Population density of nematodes which penetrated DBM larvae reached 9 ± 3I IJs·larva-1 for H. sonorensis KF723827 and 6 ± 2 IJs·larva-1 for Steinernema sp. 83a. In cadaver of DBM, nematode reproduction did not appear to be affected by the contact with insecticides. Conclusions. Based on our research, we conclude that the three insecticides did not affect EPNs efficiency and could be used in combination against DBM.

scholarly journals Efficacy of Two Entomopathogenic Nematode Species as Potential Biocontrol Agents against the Diamondback Moth, Plutella xylostella (L.)

2016 ◽  
Vol 30 (2) ◽  
pp. 78
Author(s):  
Masaaod Zolfagharian ◽  
Ayatollah Saeedizadeh ◽  
Habib Abbasipour
Keyword(s):  
Plutella Xylostella ◽  
Laboratory Experiments ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Nematode Species ◽  
Steinernema Carpocapsae ◽  
Important Pest ◽  
High Larval Mortality

The diamondback moth, <em>Plutella xylostella</em> (L.) (Lepidoptera: Plutellidae) is an important pest of cruciferous crops in Iran. The susceptibility of <em>P. xylostella</em> larvae to two species of entomopathogenic nematodes (EPNs) (<em>Steinernema carpocapsae</em> and <em>Heterorhabditis bacteriophora</em>) was examined under laboratory conditions. Leaf bioassays were conducted to evaluate the nematode's capability to reach the larvae and kill them. High larval mortality (72.6-96%) was observed in laboratory experiments. The ET<sub>50</sub> of <em>H. bacteriophora</em> was higher than that of <em>S. carpocapsae</em>. The ET<sub>50</sub> of entomopatpgenic nematodes, <em>H. bacteriophora</em> and <em>S. carpocapsae</em> tested ranged from 21 to 139.7 and 11.3 to 71.4 hours, respectively. The effect of both factors infective juveniles (IJs) and exposure time of 50% (ET50) on the larval mortality was significant (df = 6; P &lt; 0.001) and (df = 2; P &lt; 0.001), respectively. This study revealed that entomopatogenic nematodes (EPNs) have great potential that should be exploited in diamondback moth, <em>P. xylostella</em> management.

Virulence of entomopathogenic nematodes against developmental stages of Plutella xylostella (Lepidoptera: Plutellidae) — effect of exposure time

Nematology ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Naser Eivazian Kary ◽  
Samira Chahardoli ◽  
Davoud Mohammadi ◽  
Aoife B. Dillon
Keyword(s):  
Exposure Time ◽  
Negative Correlation ◽  
Plutella Xylostella ◽  
Entomopathogenic Nematodes ◽  
Developmental Stages ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Steinernema Carpocapsae ◽  
Data Sets ◽  
Dose Levels

Summary The virulence of entomopathogenic nematodes (EPN) Steinernema carpocapsae, S. feltiae and Heterorhabditis bacteriophora was evaluated against the diamondback moth, Plutella xylostella. The results revealed that diamondback moth mortality was affected by its developmental stage. For both Steinernema species, diamondback moth larval mortality peaked at 18 infective juveniles (IJ) larva−1; similar results were recorded for H. bacteriophora, with mortality peaking at 20 IJ larva−1. Mortality of pre-pupa exposed to Steinernema species increased up to 35 IJ pre-pupa−1; in S. feltiae a decreasing trend was recorded at higher concentrations of IJ. A negative correlation was recorded between LC50 and ln ET values; S. carpocapsae appeared as the most virulent EPN against larvae (6.5 IJ larva−1) and H. bacteriophora was an effective EPN against pre-pupae (6.5 IJ pre-pupa−1). EPN virulence at dose levels was evaluated by plotting LC50 against ln exposure time, and in the majority of data sets deviations from a linear model were observed and data were statistically fitted by a two-stage phase.

scholarly journals Virulence of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) for the control of Diabrotica speciosa germar (coleoptera: chrysomelidae)

2011 ◽  
Vol 35 (6) ◽  
pp. 1149-1156 ◽  
Author(s):  
Viviane Santos ◽  
Alcides Moino Junior ◽  
Vanessa Andaló ◽  
Camila Costa Moreira ◽  
Ricardo Alves de Olinda
Keyword(s):  
Biological Control ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Larval Mortality ◽  
Steinernema Glaseri ◽  
Soil Insects ◽  
Diabrotica Speciosa ◽  
Pupal Mortality

Entomopathogenic nematodes (EPNs) are used in biological control of soil insects and show promise in the control of D. speciosa. The objective of this work was to evaluate the potential of native and exotic entomopathogenic nematode isolates in the control of D. speciosa under laboratory and greenhouse conditions. Results showed that all of EPNs caused larval mortality. The most virulent were Heterorhabditis sp. RSC01 (94%), Steinernema glaseri (84%), Heterorhabditis sp. JPM04 (82%) and Heterorhabditis amazonensis RSC05 (78%). There was no effect of the Heterorhabditis sp. RSC01 and S. glaseri isolates on eggs. The maximum mortality of D. speciosa larvae by Heterorhabditis sp. RSC01 was observed at a concentration of 300 IJ/ insect, while by S. glaseri observed the highest mortality at the concentration of 200 IJ/ insect. The Heterorhabditis sp. RSC01 isolate caused over 80% pupal mortality at a concentration of 250 IJ/insect. The virulence of Heterorhabditis sp. RSC01 and S. glaseri was affected by temperature. The Heterorhabditis sp. RSC01 isolate caused reduction in larva survival under greenhouse conditions at all of the tested concentrations and there was no difference in mortality among different concentrations of infectid juveniles.

scholarly journals Behavioural responses of diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) to extracts derived from Melia azedarach and Azadirachta indica

2005 ◽  
Vol 95 (5) ◽  
pp. 457-465 ◽  
Author(s):  
D.S. Charleston ◽  
R. Kfir ◽  
L.E.M. Vet ◽  
M. Dicke
Keyword(s):  
Azadirachta Indica ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Feeding Deterrent ◽  
Botanical Insecticides ◽  
Melia Azedarach ◽  
Larval Behaviour ◽  
Control Programmes ◽  
The Impact ◽  
Higher Doses

AbstractThe impact of three different doses of botanical insecticide derived from the syringa tree, Melia azedarach and the neem tree, Azadirachta indica was tested on the behaviour of the diamondback moth, Plutella xylostella (Linnaeus). Both botanical insecticides had a significant impact on larval behaviour. At higher doses the extracts showed feeding deterrent activity, with larvae preferring the untreated sides of cabbage leaves and consuming less of the treated half of cabbage leaves. The botanical insecticides had less of an effect on the oviposition behaviour of P. xylostella moths. In laboratory and glasshouse trials, significantly fewer eggs were oviposited on the plants that had been treated with syringa extracts. Therefore, the syringa extracts appear to have a repellent effect. In contrast, when exposed to the neem extracts the moths did not discriminate between control plants and treated plants. Behavioural observation indicated that, despite the lower number of eggs oviposited on cabbage treated with syringa extracts, the moths chose cabbage treated with the highest dose of syringa more often than they chose control cabbage plants. Similar observations were found in cabbage plants treated with neem, moths chose the medium dose more often than they chose the control. Oviposition and feeding deterrent properties are important factors in pest control, and results from this study indicate that botanical insecticides have the potential to be incorporated into control programmes for P. xylostella in South Africa.

Host-Plant Specific Feeding Relationships and Insect Developmental Stage Modulate the Impact of Rainfall on Diamondback Moth Larvae

2019 ◽  
Author(s):  
M D Mahbubur Rahman ◽  
Myron P Zalucki ◽  
Michael J Furlong
Keyword(s):  
Host Plant ◽  
Chinese Cabbage ◽  
Host Plants ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Feeding Site ◽  
Feeding Sites ◽  
Leaf Surfaces ◽  
The Impact ◽  
Oviposition Sites

Abstract The impact of simulated rainfall on diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), larvae depends on their stage-specific feeding behavior, physical characteristics, and host plants. Neonates released at typical oviposition sites on Chinese cabbage (Brassica rapa var. pekinensis L. [Brassicales: Brassicaceae]) plants moved less (3–72 cm) and spend shorter periods (>1 h) than it has been previously reported for common cabbage (Brassica oleracea var. capitata L. [Brassicales: Brassicaceae]) (>80 cm and >3 h, respectively) before establishing feeding sites. On both host plants, larvae spent longer on the abaxial surfaces of leaves and were more likely to establish mines there than on the adaxial surfaces. On Chinese cabbage plants, ≈40% of neonates were removed when exposed to rainfall (5.6 cm/h for 3 min) within 5 min of release. Larval losses decreased rapidly as the interval between release and rainfall exposure increased and exposure to rainfall 2 h after release did not affect survival. On common cabbage plants, ≈65% of neonates were removed when exposed to rainfall within 30 min of release, losses decreased as the interval between release and rainfall exposure increased, but they decreased more slowly than on Chinese cabbage, and rainfall caused significant larval mortality up to 4 h after release. Rainfall also affected later instar larvae (susceptibility: 2nd> 3rd = 4th) but neither the susceptibility of these larvae nor that of pupae was affected by the host plant. Wet leaf surfaces disrupted movement and feeding site establishment by neonates. When dislodged from plants on to the surface of wet soil, most later stage larvae could relocate host plants, but most neonates could not.

scholarly journals Comparative efficacy of endophytic versus foliar application of the entomopathogenic fungus Beauveria bassiana against the crucifer diamondback moth larvae for sustainable cabbage protection

2020 ◽  
Vol 14 (4) ◽  
pp. 1448-1458
Author(s):  
Gabriel A. Heviefo ◽  
Seth W. Nyamador ◽  
Seth W. Nyamador ◽  
Benjamin D. Datinon ◽  
Isabelle A. Glitho ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Plutella Xylostella ◽  
Untreated Control ◽  
Molecular Mechanisms ◽  
Foliar Application ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Mortality Rates ◽  
Comparative Efficacy ◽  
Larval Instars

In recent investigations, Beauveria bassiana has been reported to be pathogenic to insect, endophytically colonize cabbage plants and may, therefore, be an alternative to chemical control of the diamondback moth, Plutella xylostella. In this study, the comparative efficacy of endophytic and foliar application of B. bassiana was assessed on different larval instars of P. xylostella. Cabbage plants were inoculated with B. bassiana conidia using seed coating and root soaking methods. Six weeks after plant endophytic inoculation, larval instars 2, 3 and 4 of P. xylostella were released on endophytic plant leaves without fungal spraying, on non-endophytic leaves sprayed immediately with fungal formulation and on untreated control leaves. Our results indicate that the average mortality rates of larval instars 2, 3 and 4 were significantly higher (P < 0.0001) on plants colonized by the endophyte than non-inoculated, untreated control plant. Similarly, significant differences were obtained between the foliar spraying of the fungus (corrected mortalities ≥ 96.72%) and the endophytic applications (corrected mortalities ≤ 57.61 %). In endophytic treatments, larval mortality rates varied with larval age. Further investigations are needed to elucidate the cellular and molecular mechanisms of B. bassiana endophytism in cabbage.Keywords: Fungal endophyte, foliar application, cabbage plant, Plutella xylostella, larval mortality, cadaver sporulation.

scholarly journals Antifeedant and Insecticidal Effect of Hexane Botanical Extracts on Diamondback moth (DBM), Plutella xylostella L.. (Lepidoptera: Plutellidae)

2021 ◽  
Vol 108 (special) ◽  
Author(s):  
Susmitha S ◽  
◽  
Shanthi M ◽  
Murugan M ◽  
Senthil K ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Larval Mortality ◽  
Diamondback Moth ◽  
Management Strategies ◽  
Adult Emergence ◽  
Developmental Period ◽  
Formulation Development ◽  
Insecticidal Effect ◽  
Soxhlet Apparatus ◽  
Significant Difference

Diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae) is one of the nefarious pests of cruciferous crops. Crude extracts from six botanicals obtained using hexane by continuous hot percolation process in Soxhlet apparatus were evaluated for their effect on larval mortality, antifeedant, growth and development of second instar larvae of DBM. The results revealed that the antifeedant index of Sesbania grandiflora 5% was 20.82% followed by Swietenia macrophylla 5%, which had 15.61%. The larval mortality and adult emergence exhibited by S. grandiflora was (66.67% and 33.33% respectively) after 72 h of feeding on treated leaf. It was statistically on par with S. macrophylla, which had 63.33% larval mortality and 36.67% adult emergence. With regard to the developmental period of life stages, no significant difference was observed among the treatments. However, all the treatments were significantly superior over untreated check in prolonging the developmental period of DBM. It was concluded that the S. grandiflora and S. macrophylla hexane leaf extract 5% are promising botanicals against P. xylostella, as they possess insecticidal, antifeedant and growth inhibitory activity. These results open up the scope for further isolation of bioactive compounds and validation under field conditions, which would lead to formulation development, ultimately it can be incorporated as ecofriendly component in the integrated pest management strategies.

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