Virulence of entomopathogenic nematodes to different stages of the flatheaded root borer, Capnodis tenebrionis (L.) (Coleoptera: Buprestidae)

Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Ana Morton ◽  
Fernando García-del-Pino

AbstractThe virulence of 14 Steinernema feltiae isolates, one S. carpocapsae and three Heterorhabditis bacteriophora isolates was compared in the laboratory against larvae, pupae and adults of the flatheaded root borer, Capnodis tenebrionis. Larval mortality ranged from 50 to 100% and pupae mortality from 0 to 70%. Adults were exposed to different nematode concentrations, 50 and 100 infective juveniles/cm2. Steinernema feltiae caused the highest mortality at the two doses tested, reaching 66.7% and 100%, respectively. Significant differences in mortality between C. tenebrionis males and females were observed. The differences in virulence observed at each stage of C. tenebrionis vary within a species and can be higher than differences among species. The results of this study suggest that some of the isolate strains have potential for improved biological control of C. tenebrionis.

Author(s):  
Américo de Castro Monteiro Sobrinho ◽  
Isadora Luiza Alves Costa ◽  
Graziele Calixto Souza ◽  
Luís Carlos de Souza Rodrigues Leal ◽  
João Luiz Lopes Monteiro Neto ◽  
...  

Abstract Stomoxys calcitrans is a hematophagous dipteran. Several agents are used in biological control, including entomopathogenic nematodes (EPNs). Bioassay I involved an evaluation of the effect of Heterorhabditis bacteriophora HP88 and Heterorhabditis baujardi LPP7 on S. calcitrans larvae in different periods of exposure. Groups of 10 larvae were placed in Petri dishes and 200 EPNs/larva were added, which were divided into groups according to the exposure times of 2, 4, 6, 12, 24 and 48 hours. The purpose of Bioassay II was to evaluate the efficacy of the EPNs in infecting S. calcitrans larvae when they were isolated from stable fly larvae in Bioassay I. Groups of 10 larvae were placed in Petri dishes and 200 EPNs/larva were added. In bioassay I, H. bacteriophora caused mortality rates of 51.7, 83.3 and 91.7% in 12, 24 and 48 hours, respectively, while H. baujardi caused mortality rates of 9.3 (12h), 35 (24h) and 35% (48h). In Bioassay II, H. bacteriophora and H. baujardi resulted in mortality rates of 35% and 25%, respectively. It was concluded that the longest exposure times presented the highest larval mortality and that EPNs isolated from S. calcitrans are not efficient in controlling the larvae fly.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Indra Kumar Kasi ◽  
Mohinder Singh ◽  
Kanchhi Maya Waiba ◽  
S. Monika ◽  
M. A. Waseem ◽  
...  

Abstract Background Entomopathogenic nematodes (EPNs) have the potential to supersede larvicidal activity for the management of various insect pests. Result Lab experiments were conducted to test the pathogenicity of 2 EPNs local species; Steinernema feltiae and Heterorhabditis bacteriophora at different (IJs/cm2) concentrations against the cabbage butterfly, Pieris brassicae (L.). The native isolate was obtained from soil samples, collected from Rajgarh, Hamachi Pradesh, India. Petri dish bioassay used the EPNs species (S. feltiae HR1 and H. bacteriophora HR2) at the concentrations (0, 10, 20, 40, 80, 160 IJs/cm2). Based on the pathogenicity of the strains, only 2 isolates effectively showed larvicidal activity. The highest (%) (72.08 and 67.42%), at the 2nd instar larval mortality was recorded in the treatments with H. bacteriophora and S. feltiae at160 IJs/cm2, respectively. At the 4th instar larvae, respective larval mortality (85.38, 69.50%) was recorded in treatment with H. bacteriophora, and S. feltiae, respectively, at160 IJs/cm2. In case of pupae, the mortality rates were (62.12, 58.58%) for H. bacteriophora and S. feltiae, respectively, at 160 IJs/cm2; (74 and 12%) for both the tested EPNs, respectively, at 80 IJs/cm2. Percent of P. brassicae larval mortality treated with the tested EPN isolates was significantly higher than the untreated control. Results revealed that the percent of larval mortality significantly increased with the increase in time periods, being maximum at 72 h. S. feltiae and H. bacteriophora, strains showed potent larvicidal activity at low concentration even at 48 and 72 h of exposure. Conclusion This study revealed that the local strains of EPNs (S. feltiae HR1 and H. bacteriophora HR2) were found as a biocontrol agent against P. brassicae.


2011 ◽  
Vol 35 (6) ◽  
pp. 1149-1156 ◽  
Author(s):  
Viviane Santos ◽  
Alcides Moino Junior ◽  
Vanessa Andaló ◽  
Camila Costa Moreira ◽  
Ricardo Alves de Olinda

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.


2021 ◽  
Vol 37 ◽  
pp. e37047
Author(s):  
Sandra Mara Chaneiko ◽  
Andressa Lima de Brida ◽  
Daniel Bernardi ◽  
Luis Garrigós Leite ◽  
Flávio Roberto Mello Garcia

Anastrepha fraterculus (Wiedemann) is one of the main pests of fruit farming, and entomopathogenic nematodes (EPNs) represent an important control tool of this species. Thus, the objective of this study was to evaluate the biological activity of different isolate against A. fraterculus larvae and adults. Bioassays were performed using a suspension of three isolates of Heterorhabditis amazonensis IBCB 24, Steinernema carpocapsae IBCB 02 and Steinernema feltiae IBCB 47 at six concentrations (control - without nematodes), 50, 150, 300, 500, 1000 and 1500 infective juveniles (IJs)/mL of water per 3º instar larvae. It was verified the susceptibility of larvae of A. fraterculus to isolates of EPNs and a significant increase of the pupal mortality in the function of the concentration of IJs inoculated by larva (above 75%). After the dissection of pupae and adults of A. fraterculus from infected larvae, the concentration of 1500 IJs/mL of EPNs provided the highest rate of multiplication of IJs by insect, equating to maximum concentration tested 1500 IJs/mL. Adults of A. fraterculus from larvae infected with EPNs longevity of five days, being less than adults from uninfected larvae by IJs (135 days). H. amazonensis IBCB 24, S. carpocapsae IBCB 02, and S. feltiae IBCB 47 proved to be promising as agents of biological control of A. fraterculus.


2020 ◽  
Vol 6 (4) ◽  
pp. 359
Author(s):  
Jiří Nermuť ◽  
Jana Konopická ◽  
Rostislav Zemek ◽  
Michal Kopačka ◽  
Andrea Bohatá ◽  
...  

Entomopathogenic nematodes and fungi are globally distributed soil organisms that are frequently used as bioagents in biological control and integrated pest management. Many studies have demonstrated that the combination of biocontrol agents can increase their efficacy against target hosts. In our study, we focused on another potential benefit of the synergy of two species of nematodes, Steinernema feltiae and Heterorhabditis bacteriophora, and the fungus Isaria fumosorosea. According to our hypothesis, these nematodes may be able to disseminate this fungus into the environment. To test this hypothesis, we studied fungal dispersal by the nematodes in different arenas, including potato dextrose agar (PDA) plates, sand heaps, sand barriers, and glass tubes filled with soil. The results of our study showed, for the first time, that the spreading of both conidia and blastospores of I. fumosorosea is significantly enhanced by the presence of entomopathogenic nematodes, but the efficacy of dissemination is negatively influenced by the heterogeneity of the testing arena. We also found that H. bacteriophora spread fungi more effectively than S. feltiae. This phenomenon could be explained by the differences in the presence and persistence of second-stage cuticles or by different foraging behavior. Finally, we observed that blastospores are disseminated more effectively than conidia, which might be due to the different adherence of these spores (conidia are hydrophobic, while blastospores are hydrophilic). The obtained results showed that entomopathogenic nematodes (EPNs) can enhance the efficiency of fungal dispersal.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fouad Mokrini ◽  
Salah-Eddine Laasli ◽  
Youssef Benseddik ◽  
Abdelmalek Boutaleb Joutei ◽  
Abdelali Blenzar ◽  
...  

Abstract The Mediterranean fruit fly, Ceratitis capitata Wiedemann, is a deleterious pest worldwide affecting fruit production. The entomopathogenic nematodes (EPNs) are a potential biocontrol agent that could be effectively used to control this Mediterranean fruit fly. In this study, five EPN strains reported from different fields in Morocco were evaluated for their efficacy against C. capitata. In laboratory assays, Steinernema feltiae-SF-MOR9, S. feltiae-SF-MOR10 and Heterorhabditis bacteriophora-HB-MOR7 strains showed significantly higher infectivity and penetration rates when compared to the other strains. S. feltiae-SF-MOR9 caused the highest larval mortality rate (80%) at 50 infective juveniles (IJs) cm−2. However, additional results showed that both S. feltiae strains were significantly effective in controlling C. capitata larvae in apricot (Prunus armeniaca) fruits on soil surface with high mortality rate at 50 and 100 IJs cm−2. Different soil textures and moisture levels resulted in a significant variation in EPN strain virulence against C. capitata. Sandy clay loam soil in combination with 50 IJs cm−2 of S. feltiae (SF-MOR9 or SF-MOR10) caused a higher mortality rate of C. capitata larvae. Furthermore, applying these EPN strains at 50–100 IJs cm−2 in combination with 10–15% moisture level showed optimal results against C. capitata larvae. Therefore, those two Moroccan EPN strains could be used as promising eco-friendly biological agents against C. capitata.


Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 321-327 ◽  
Author(s):  
Alper Susurluk

AbstractTo determine the seasonal movement of the dauer juvenile (DJ) stage of entomopathogenic nematodes, DJ of Heterorhabditis bacteriophora (TUR-H2) and Steinernema feltiae (TUR-S3) were applied to field plots (turf and fallow) and their vertical distribution in soil was monitored for 8 months (October to June) in Turkey. Most S. feltiae remained near the soil surface (0-15 cm deep) in both kinds of plots and throughout the study. By contrast, H. bacteriophora moved to 40 cm depth in fallow plots during winter months but remained mostly near the soil surface (0-15 cm deep) in turf plots throughout the study.


Nematology ◽  
2008 ◽  
Vol 10 (5) ◽  
pp. 701-709 ◽  
Author(s):  
Samuel A. Anbesse ◽  
Bekele J. Adge ◽  
Wondirad M. Gebru

Abstract The barley chafer grub, Coptognathus curtipennis, is an important field pest of barley, wheat and linseed seedlings at Tikur Inchini district of theWest Shewa zone of Ethiopia in Ormoia regional state. Two entomopathogenic nematodes (EPN; Heterorhabditis bacteriophora and Steinernema yirgalemense, strains ANEPN21, ANEPN22, respectively) and three entomopathogenic fungal isolates of Metarhizium anisopliae (MM, EE and PPRC66) were compared separately at different rates of concentration for their effect against C. curtipennis in laboratory bioassays. Heterorhabditis bacteriophora and M. anisopliae isolate MM were found to be the most pathogenic to C. curtipennis at 1000 infective juveniles (IJ)/grub and 108 conidia (g soil)–1 concentration, causing 88.7% and 88.6% mortality, respectively, after 3-4 weeks exposure. These two most effective entomopathogens were further tested against the same insect in simultaneous and sequential combination with each other. Insect larvae were exposed to optimal concentration of H. bacteriophora and M. anisopliae isolate MM, which caused 50% larval mortality, i.e., 380 IJ/grub and 1.7 × 107 conidia (g soil)–1, respectively, as observed in the first experiments. The combined application increased larval mortality in an additive and synergistic manner. To achieve a strong synergistic effect, larva had to be exposed to M. anisopliae isolate MM 3 weeks before the addition of nematodes. The result of the whole experiment suggests that the damage caused by barley chafer grub can be controlled or managed by applying EPN and/or fungi. Furthermore, the combined use of M. anisopliae with nematodes may offer an integrated approach to increase the efficacy of EPN for C. curtipennis control and perhaps other insect pests.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
K. Sindhura Bhairavi ◽  
Badal Bhattacharyya ◽  
Gitanjali Devi ◽  
Sudhansu Bhagawati ◽  
Partha Pratim Gyanudoy Das ◽  
...  

Abstract Background Entomopathogenic nematodes (EPNs) are one of the widely studied biological control agents. The present study was conducted to evaluate the efficacy of two EPNs species, Heterorhabditis bacteriophora (Poinar) (Rhabditida: Heterorhabditidae) and Steinernema aciari (Qui, Yan, Zhou, Nguyen and Pang) (Rhabditida: Steinernematidae), isolated locally from soils of Majuli river island, Assam, India against two important subterrenean pests; Odontotermes obesus (Rambur) (Isoptera: Termitidae) and Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) under laboratory conditions. Results In case of O. obesus, mortality percent was recorded by H. bacteriophora after 72 h. at 300 IJs/termite and by S. aciari at 250 and 300 IJs/termite after 96 h. The lowest LD50 and LT50 values obtained for H. bacteriophora were 13.054 IJs/termite and 26.639 h., respectively, while those of S. aciari were 42.040 IJs/termite and 31.761 h., respectively. With respect to A. ipsilon, H. bacteriophora registered a highest mortality rate at 300 IJs/larvae after 144 h. S. aciari showed 100 percent mortality at 300 IJs/larva after 168 h. The lowest values of LD50 and LT50 for H. bacteriophora were 35.711 IJs/larva and 83.050 h., respectively. The lowest values of LD50 and LT50 for S. aciari were 71.192 IJs/larvae and 97.921 h., respectively. Overall, H. bacteriophora displayed more virulence toward O. obesus and A. ipsilon than S. aciari. Conclusion Both native EPNs were found effective against O. obesus and A. ipsilon. However, H. bacteriophora was more virulent toward O. obesus and A. ipsilon than S. aciari under the laboratory conditions.


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