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

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.

2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Amany M. Abd El Azim

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.


2007 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Chaerani Chaerani ◽  
Y. Suryadi ◽  
T.P. Priyatno ◽  
D. Koswanudin ◽  
U. Rahmat ◽  
...  

Isolation of Entomopathogenic Nematodes Steinernema and Heterorhabditis. Entomopathogenic nematodes from the genus Steinernema and Heterorhabditis (Rhabditida: Steinernematidae and Heterorhabditidae) are promising biological control agent of insect pests. Indigenous nematodes have been isolated and collected for the use in local biological control program of important insect pests. The nematodes were isolated using soil baiting method with insect larvae. Laboratory tests have shown that the mealworm larvae Tenebrio molitor (Coleoptera: Tenebrionidae) served as a good alternative to the standard insect bait, the greater wax moth larvae Galleria mellonella (Lepidoptera: Galleriidae) for isolation and maintenance of nematodes. Both nematodes were successfully isolated using T. molitor larvae from 13% soil samples (26 out of a total of 207) collected from 14 locations in West and Central Java and Lampung provinces in the period of 1993 until 2006. Heterorhabditis (9%) was more prevalent than Steinernema (4%). Both nematodes were successfully propagated on mealworm larvae.


2021 ◽  
Vol 11 (9) ◽  
pp. 4066
Author(s):  
Spiridon Mantzoukas ◽  
Ioannis Lagogiannis ◽  
Aristeidis Ntoukas ◽  
George T. Tziros ◽  
Konstantinos Poulas ◽  
...  

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.


2011 ◽  
Vol 43 (2) ◽  
pp. 269
Author(s):  
Behzad Habibpour ◽  
Amir Cheraghi ◽  
Mohammad Saeed Mossadegh

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.


1993 ◽  
Vol 28 (2) ◽  
pp. 182-190 ◽  
Author(s):  
J. P. Parkman ◽  
W. G. Hudson ◽  
J. H. Frank ◽  
K. B. Nguyen ◽  
G. C. Smart

The first successful inoculative releases of an entomopathogenic nematode, Steinernema scapterisci Nguyen and Smart, for the control of exotic pests, Scapteriscus spp. mole crickets, were made at three pasture sites in Alachua County, Florida in 1985. Based on the evaluation of field-collected crickets, the nematode was established at all sites and persisted for over 5 years. Mean yearly percentage of infected crickets ranged from 0 to 21.4% for individual release sites. Mean adult infection level for all years combined, 10.9%, was significantly greater than that for nymphs (2.5%) and infection levels for Scapteriscus borellii Giglio-Tos, 12.7%, was significantly greater than that for Scapteriscus vicinus Scudder (4.5%) for all years combined. Although 24 h trap catch results indicate mole cricket populations were significantly reduced, the nematode's effect on pest abundance could not be adequately assessed because of the variation in trap catch results and inadequate knowledge about the relationship between trap catch and the mole cricket field populations being sampled. Despite inadequacies in estimating pest abundance, the results indicate S. scapterisci has potential as a biological control agent for pest mole crickets in the genus Scapteriscus.


Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 439-451 ◽  
Author(s):  
Martin Downes ◽  
Conor Meade ◽  
Stephen Boyle ◽  
Alec Rolston ◽  
Thomae Kakouli-Duarte

AbstractThe application of large numbers of entomopathogenic nematodes (EPN) to control insect pests of agriculture is likely to have an impact on the local EPN fauna, yet little is known about the intraspecific relationships between EPN populations, particularly with regard to phylogeny and outbreeding. Here we assess the fitness, with regards to fecundity, host insect mortality and time taken to produce progeny, of isolates of Steinernema feltiae from Bull Island, Ireland. Exon-primed, intron-crossing (EPIC) PCR was used to examine intraspecific phylogenies between S. feltiae isolates, and identified up to three possible colonisation events of Bull Island. EPIC-PCR grouped two isolates, 33.D.(2) and 59.F.(2), separately from the remaining ten S. feltiae isolates These same two isolates consistently performed poorly in all fitness assessments. Following the crossbreeding of all isolates in Galleria mellonella, the number of host cadavers exhibiting emerging infective juveniles was significantly fewer than expected and there were significant differences between isolates in the number of days until progeny were observed. Host insect mortality varied between 40 and 87%. Such intraspecific variation may be a result of adaptation to different microhabitats of Bull Island, which in turn may be accentuated by laboratory culture practices.


2004 ◽  
Vol 94 (2) ◽  
pp. 159-167 ◽  
Author(s):  
S. Jess ◽  
J.F.W. Bingham

AbstractIn small-scale experiments, the predatory mites, Hypoaspis aculeifer (Canestrini) and H. miles Berlese, applied at 700 mites m−2, and the entomopathogenic nematode, Steinernema feltiae (Filipjev) applied at 3 × 10−6 nematodes m−2 controlled sciarids and phorids in mushroom compost and casing substrates. For both mite species, earliest application to the growing substrate following sciarid infestation reduced sciarid emergence. In contrast, later application of each biological control agent provided more effective control of phorid emergence. The behaviour of adult mites suggested that H. aculeifer were more positively geotactic than H. miles although both species could penetrate compost and casing substrates to a depth of 2–12 cm. A majority of S. feltiae nematodes resided at a depth of 2–4 cm in both substrate types. Independent application of H. aculeifer provided more comprehensive control of sciarids and phorids than the other biological agents studied, owing to its better dispersal within compost and casing, and ability to attack larvae of differing ages.


1962 ◽  
Vol 94 (5) ◽  
pp. 477-486 ◽  
Author(s):  
W. A. Smirnoff ◽  
J. J. Fettes ◽  
W. Haliburton

Neodiprion swainei Middleton is the most serious defoliator of jack pine, Pinus bamksiana Lambert, in Canada. The damage to stands of this species in northern Quebec has been extensive and has resulted in considerable forest-fire hazard. Virus infected sawflies were found in the Lac Gagnon area in Quebec in 1956, and a study of the disease was begun by the Quebec Laboratory in 1957. Laboratory propagation methods were developed and resulted in the production of a quantity of polyhedral concentrate of a virulent strain. Concentrations of polyhedral bodies needed in a spray formulation to infect and kill larvae of various ages were determined in the laboratory and field tests demonstrated the potentialities of this disease as a biological control agent (Smirnoff 1960b, 1961a). These studies served as a basis for the experiment in the dissemination of the disease by aircraft described in this paper.


2015 ◽  
Vol 55 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Keivan Karimi ◽  
Mahdi Arzanlou ◽  
Asadollah Babai Ahari ◽  
Mostafa Mansour Ghazi

AbstractWe report the first case of chafer beetle [Anisoplia austriaca(Herbst 1783)] mortality caused byActinomucor elegansvar.elegansin wheat fields of the Kurdistan province, Iran. For three years, dead larvae ofAnisoplia austriacawere collected from wheat fields of the Kurdistan province. Similar isolates of a fast-growing fungus were recovered from all samples. The fungal isolates were identified asA. elegansvar.elegansbased on morphological and cultural characteristics. The identity of the species was further confirmed using sequence data of the ITS (Internal Transcribed Spacer) region of ribosomal DNA. Koch’s postulates were fulfilled by the inoculation of the larvae ofA. austriacaandGalleria mellonella(Linnaeus, 1758) (as the model insect) using the spore suspension ofA. elegansvar.elegans. The viability of sporangiospores was evaluated using a spore dilution technique on germination medium. The results on the pathogenicity (100% mortality inA. austriacalarvae) and viability tests (germination: 95.45%) demonstrated thatA. elegansvar.eleganscan be considered as a potential biocontrol agent against the chafer beetle. Field experiments are still required to evaluate the capacity ofA. elegansas a biological control agent.


2021 ◽  
Vol 13 (3) ◽  
pp. 93
Author(s):  
C. N. Ngugi ◽  
P. M. Wachira ◽  
J. N. Mbaka ◽  
S. Okoth ◽  
S. Haukeland ◽  
...  

Entomopathogenic nematodes (EPNs) are worldwide soil-dwelling insect parasitic nematodes. They are potential pest bio-control agents a key component of Integrated Pest Management (IPM) programs. This study aimed to characterize and evaluate the pathogenicity of an EPN isolate from Kenya. The nematode was isolated from soils using insect bait technique and both morphological and molecular identification was performed. Efficacy of the isolate was evaluated against Tomato leafminer larvae (Tuta absoluta Meyrick.) using dose-based treatments of 0-control, 100, 150, 200, and 250 infective juveniles (IJs/ml). Morphological analysis revealed body length (L) of 835(659-987) &micro;m and 1781 (1297-2097) &micro;m from fresh IJs and males respectively. Males lacked a mucron. The isolate was characterized by the partial sequence length of 877 bp of the ITS region. Blastn results indicated the EPN isolate had a similarity match of 81-92% with Afro-tropical Steinernema species. It matched with Steinernema sp. (AY230186.1) from Kenya at 92% and Sri Lanka (AY230184.1). Phylogenetic analysis placed the isolate together with Steinernema sp. (AY230186.1) and (AY230184.1) with a bootstrap value of 100%. Maximum mean larval mortality (80%; 96%) was achieved 24 and 48 h post-treatment at concentration 150 IJs/ml. All nematode concentrations achieved over 50% mean mortality after 24 h period. There was a significant difference (P = 0.001) between doses 150 and 200 IJs/ml. From the study, it was concluded that the nematode isolate was Steinernema sp now referred to as Steinernema sp. Kalro (Genebank Accession MW151701). The EPN has the potential for development as a biological control agent against T. absoluta.


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