Infectivity of entomopathogenic nematodes to soil-dwelling developmental stages of the tree leaf beetles Altica quercetorum and Agelastica alni

2004 ◽  
Vol 110 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Marek Tomalak
2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Mohamed Samir Tawfik Abbas

The present review article demonstrates laboratory and field evaluations of entomopathogenic nematodes (EPNs) against different developmental stages of fruit flies. The virulence of the EPNs  differed clearly  even on the same insect species and / or by the same nematode species. Such differences might be attributed  to some reasons such as the method of treatment as well as the concentrations of the tested nematodes. Fruit flies are among the most important insect pests infesting vegetables and fruits causing considerable losses in the yields worldwide. In laboratory studies, the tested nematodes proved to be highly virulent to larvae as  percentage of  mortality may reach 100 %.  As for treated pupae, at different ages, the results are variable and controversially; some studies revealed their moderate or high susceptibility to nematode infection and others indicated low susceptibility or resistance to infection .Treated adults, or those emerged from treated larvae or pupae,  are also susceptible to infection.  In semi-field and field trials, EPNs proved to be successful for reducing the populations of some fruit flies with up to 85 % at concentrations not less than 100 infective juveniles (IJs) / cm2 of soil. However, the field applications of commercial EPNs have been recommended to be 2.5 – 5 x 109 IJs / ha (25-50 IJs/cm2 of soil).


Author(s):  
Loes J. M. F. den Nijs ◽  
Jon Pickup ◽  
Ralf-Udo Ehlers

Abstract Nematodes can be present in various parts of plants or at various depths in the soil, depending on the circumstances and the life stage. This means that one should be aware of these possibilities when collecting samples. Also, samples should be taken from the proper matrix at the appropriate time, taking into account the developmental stages the nematodes might be in. In this chapter, the purpose of sampling, sampling techniques and, related to this, the sampling tools, and the handling and storage of the samples before processing of plant-parasitic and entomopathogenic nematodes are discussed. Some protocols are described in detail as examples.


Nematology ◽  
2016 ◽  
Vol 18 (6) ◽  
pp. 743-750 ◽  
Author(s):  
Manjunatha T. Gowda ◽  
Jagadeesh Patil ◽  
Devindrappa Mansheppa ◽  
Vijayakumar Rangasamy ◽  
Abraham Verghese

Eggplant ash weevil, Myllocerus subfasciatus, is an important pest of eggplant that attacks other solanaceous crops in Asia and Southeast Asia. The potential efficacy of two species of entomopathogenic nematodes (EPN), Steinernema carpocapsae and Heterorhabditis indica, against third instar and pre-pupal stages of this pest was tested under laboratory and poly-greenhouse conditions. In this present study, both stages were susceptible to EPN species but the pre-pupal stage was more susceptible. Steinernema carpocapsae was the most effective species against pre-pupal stages. In a pot experiment, among the EPN species tested, S. carpocapsae caused significantly greater mortality (20-100%) than H. indica (16-92%) against pre-pupal stages and S. carpocapsae caused 16-92% mortality in third instar larvae, while H. indica caused (12-80%) mortality. Both EPN species were able to reproduce in third instar and pre-pupal stages of ash weevil, but progeny production rate for H. indica was significantly higher than those of S. carpocapsae. Our observations also revealed that efficacy of EPN against M. subfasciatus varies with developmental stages of M. subfasciatus and EPN species; therefore, no generalisation can be made. Our findings provide the first insight into the biocontrol potential of S. carpocapsae and H. indica against third instar and pre-pupal stages of M. subfasciatus.


Nematology ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Naser Eivazian Kary ◽  
Samira Chahardoli ◽  
Davoud Mohammadi ◽  
Aoife B. Dillon

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.


1992 ◽  
Author(s):  
Michael Samish ◽  
K.M. Kocan ◽  
Itamar Glazer

This research project was aimed to create a basis for the use of entomopathogenic nematodes (Steinernematidae an Heterorhabditidae) for biological control of ticks. The specific objectives were to determinate: 1) Nematode virulence to various. 2) Host-parasite interactions of nametodes and ticks. 3) Effect of environmental factors of tick habitats on nematode activity. 4) To test nematodes (anti tick activity) in defined field trials. Throughout the project 12 nematode strains from five species were tested in laboratory assays against all developmental stages of eight tick species. All tick species were found susceptible to nematode infection. The nematode strains the IS-5 and IS-12 of Heterorhabditis bacteriophora were found to be the most virulent. Engorged adults, particularly females, were the most susceptible stages. Despite the high susceptibility, ticks are not suitable hosts for nematode development and propagation. Entomopathogenic namatodes enter ticks and kill them by releasing the symbiotic bacteria from their foregut. Under favorable conditions, i.e. moist soil, moderate temperature (22-27oC) and sandy soil, nematode efficacy against B. annulatus engorged females was very high (>5% w/w) and high animal manure concentration in soil adversely effect nematode efficacy. In field trails, nematodes were effective when soil moisture was maintained at high levels. The results indicate that under favorable conditions the nematodes show promise as a biological control method for ticks. However, we still face several potential obstacles to the use of nematodes under less favorable conditions.


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