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The present study evaluated, in the laboratory, the virulence of Heterorhabditis bacteriophora LPP30 against engorged females of Rhipicephalus microplus; in addition, we evaluated, in semi-field tests, the effects of four isolates of Heterorhabditis spp. (i.e., H. bacteriophora HP88, Heterorhabditis baujardi LPP7, Heterorhabditis indica LPP1 and H. bacteriophora LPP30) in insect cadaver formulation against the non-parasitic phase of R. microplus. In the first experiment (in vitro), engorged females were exposed, in Petri dish, to H. bacteriophora LPP30 at 75, 150, 300, 600, 1200 and 2400 nematodes/tick (10 ticks per concentration tested). In the second experiment (semi-field), five engorged females and four cadavers of Galleria mellonella infected with nematodes were placed in pots with soil and grown Brachiaria decumbens; the pots were hold outdoor, exposed to natural environment conditions during the tests. In the third experiment (semi-field), 65 days after the cadavers had been placed in the pots for the second experiment, new engorged females (five per pot) were placed in the pots of the groups treated with H. bacteriophora HP88 or H. baujardi LPP7, to assess their persistence in the soil. In the first test, the percent control was higher than 95% in all treatment groups. In the second experiment, at day 22, the mean mortality rate was 78% in the groups treated with H. bacteriophora LPP30 or H. indica LPP1, and reached 100% and 98% when treated with H. bacteriophora HP88 and H. baujardi LPP7, respectively. In this experiment, the egg-laying inhibition index was higher than 90% in the groups treated with H. bacteriophora HP88 (97.2%) or H. baujardi LPP7 (91.9%). In the third experiment with H. bacteriophora HP88 and H. baujardi LPP7, the egg-laying inhibition index was 59.1% and 43.1%, respectively. We concluded that the isolate LPP30 was highly virulent under laboratory conditions, whereas in semi-field tests, HP88 and LPP7 were the most effective isolates. Moreover, HP88 and LPP7 remained active against engorged females of R. microplus in the soil for 65 days after application of EPN-infected cadavers of G. mellonella.

Since the 1980s, research into entomopathogenic nematodes (EPNs) in Latin America has produced many remarkable discoveries. In fact, 16 out of the 117 recognized species of EPNs have been recovered and described in the subcontinent, with many more endemic species and/or strains remaining to be discovered and identified. In addition, from an applied perspective, numerous technological innovations have been accomplished in relation to their implementation in biocontrol. EPNs have been evaluated against over 170 species of agricultural and urban insects, mites, and plant-parasitic nematodes under laboratory and field conditions. While much success has been recorded, many accomplishments remain obscure, due to their publication in non-English journals, thesis dissertations, conference proceedings, and other non-readily available sources. The present review provides a brief history of EPNs in Latin America, including current findings and future perspectives., E. San-Blas, M.G. Rodriguez and P. Morales-Montero were supported by To Fondo de Desarrollo Nacional (FONDEN S.A.), in the form of financial support through “Convenio de Cooperación Integral Cuba-Venezuela”, project “MPPF-FONDEN-CJ-CCATR-XIII-14”. Also, M.G. Rodríguez used the time and facilities granted by the European Union project, “Microbial Uptakes for Sustainable management of major banana pests and diseases” (MUSA, 727624; topic: SFS-11-2016). R. Campos-Herrera’s contribution was supported through an Investigator Program Award (IF/00552/2014) supplied by the Portuguese government. J. Ruiz-Vega thanks the Secretaría de investigación y Posgrado (SIP), Instituto Politécnico Nacional, Mexico for providing resources for the research carried out in Oaxaca from 1998 to 2010.

Oriental fruit moth Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) is considered a major pest in temperate fruit trees, such as peach and apple. Entomopathogenic nematodes (EPNs) are regarded as viable for pest management control due to their efficiency against tortricid in these trees. The objective of this study was to evaluate the effectiveness of native EPNs from Rio Grande do Sul state against pre-pupae of G. molesta under laboratory and field conditions. In the laboratory, pre-pupae of G. molesta were placed in corrugated cardboard sheets inside glass tubes and exposed to 17 different EPNs strains at concentrations of 6, 12, 24, 48 and 60 IJs/cm2 and maintained at 25 °C, 70 ± 10% RH and photophase of 16 h. Insect mortality was recorded 72 h after inoculation of EPNs. Steinernema rarum RS69 and Heterorhabditis bacteriophora RS33 were the most virulent strains and selected for field application (LC95 of 70.5 and 53.8 IJs/cm2, respectively). Both strains were highly efficient under field conditions when applied in aqueous suspension directed to larvae on peach tree trunk, causing mortality of 94 and 97.0%, respectively.

This study investigated the possible biological, biochemical and histological changes in Bradybaena similaris (Gastropoda: Pulmonata) infected by Heterorhabditis indica (Rhabditida: Heterorhabditidae), strain LPP1. Two groups of 16 snails were formed: the control group (unexposed) and the treated group, which was exposed for three weeks to infective juveniles (J3) of H. indica LPP1. The experiment was conducted in duplicate, using a total of 64 snails. After the exposure period, the snails were dissected to collect the hemolymph and tissues, for evaluation of the physiological changes caused by the infection. The number of eggs laid/snail and the viability of these eggs were also assessed as indicators of the reproductive activity of B. similaris. Intense glycogenolysis was accompanied by a significant reduction (p

The sugarcane borer, Diatraea saccharalis , makes tunnels in the cane stalk, causing weight loss, as well as bud death, impairing germination. The weakened stalks are also more prone to breakage by wind, and in young plants the inner whorl of the leaves can die, resulting in a condition known as “dead heart”. Chemical control is used, but with low efficiency. This work was designed to test biological control of D. saccharalis using entomopathogenic nematodes (NEPs). Two trials in the greenhouse were performed using Heterohabditis baujard LPP7 and Steinernema carpocapse NCAll by foliar application associated with adjuvants. In the first assay, the number of holes per stalk was 3.4 for the control without nematodes and with Joint* Oil; 3.14 for the control without nematodes and with Gotafix®; 2.44 for S. carpocapsae NCAll + Joint* Oil; 2.06 for H. baujardi LPP7 + Gotafix® and also for S. carpocapsae NCAll + Gotafix®; and 1.84 for H. baujardi LPP7 + Joint* Oil. In the second assay, the treatments showed an average of 4.78 holes per stalk for the control without nematodes and with Gotafix®; 4.76 for the control without nematodes and with Joint* Oil; 2.18 for S. carpocapsae NCAll + Joint* Oil and for S. carpocapsae NCAll + Gotafix®; 1.96 for H. baujardi LPP7 + Gotafix®; and 1.90 for H. baujardi LPP7 + Joint* Oil. In the two experiments, the treatments with and without the EPNs differed significantly, but there was no difference between the adjuvants or between the two EPN species.

The aim of this study was to assess the influence of different exposure times of engorged female the Rhipicephalus microplus to infective juveniles of Heterorhabditis bacteriophora isolate HP88. The engorged females were divided into seven groups (six treatments and one control) of 20 ticks each with statistically similar average weights (p>0.05) and exposed to concentrations of 300 nematodes/tick for periods of 3, 6, 12, 24, 48 and 72h. The following biological parameters were monitored: pre-oviposition period; egg mass weight; hatching percentage; and efficacy of treatment. There was no influence of the exposure time on the pre-oviposition period (p>0.05), while there were significant differences (p

The Brazilian apple leafroller, Bonagota salubricola (Meyrick, 1937) ( Bonagota cranaodes ) (Lepidoptera: Tortricidae), is one of the main pest problems in apple orchards is Brazil. The purpose of this work was to evaluate B. salubricola larval and pupal susceptibility to different species of entomopathogenic nematodes, isolated in Rio Grande do Sul state in Brazil, under laboratory and field (apple orchard) conditions. Bioassays for isolates selection and determination of lethal concentration were performed in tubes of 1.5 ml (eppendorf), each containing one B. salubricola third instar larvae and filter paper. Field experiments were performed in commercial orchard, with application of 100 infecting juveniles (IJs)/cm 2 for each apple plant previously infected with five B. salubricola larvae covered with plastic trays containing thin cloth. Nematodes H. bacteriophora RS107 and H. bacteriophora RS57 had LC 50 of 13 and 4.5 IJs/larvae (4.3 and 1.5 IJs/cm 2 ), respectively. In the field, H. bacteriophora RS107 and H. bacteriophora RS57, applied with sorbitol as an adjuvant, reached 70.2 and 61.1% larval mortality, respectively. The results showed that both isolates had biological activity against B. salubricola under laboratory and field conditions.

In orchards, in cases where the insect pests are concentrated under the canopy, entomopathogenic nematodes can be applied as infected host cadavers. This study evaluated the distribution of Heterorhabditis baujardi Phan, Subbotin, Nguyen & Moens strain LPP7 applied as one or 15 host cadavers per plot in a guava orchard. The plots were located between guava trees, with the host cadavers being placed in the centre. Soil samples were taken at 1, 3, 5, 8 and 10 weeks after cadaver application. On each date, the plots were sampled at 30, 60, 90 and 120 cm from the cadaver application point and at three different depths (0 – 10, 10 – 20 and 20 – 30 cm). The highest average number of recovered infective juveniles was found at 90 cm from the cadaver application point, and at 10 cm depth and on the fifth week after application. There was no significant effect on the number of recovered infective juvenile nematodes, when they were applied as one or 15 cadavers, although the most uniform dispersal was found when 15 ...

Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondonia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.

The guava weevil, Conotrachelus psidii, is a major pest of guava in Brazil causing severe reduction in fruit quality. We assessed its susceptibility to Heterhorhabditis baujardi LPP7 infective juveniles (IJs) in the greenhouse and under field conditions applying the nematodes in cadavers of seventh instar Galleria mellonella larvae. Field persistence of these nematodes in the soil was evaluated through G. mellonella-baiting. Insect cadaver concentrations of 2, 4 and 6 applied in pots in the greenhouse experiment caused significant mortality compared to the control. Significance differences were observed in the field between control and treatments only when six cadavers per 0.25 m2 were applied. Infective juveniles from the cadavers persisted 6 weeks after application in the field, but decreased greatly thereafter. Our work demonstrates that H. baujardi LPP7 IJs emerging from G. mellonella cadavers can be efficacious against guava weevil fourth instar larvae. Also, we demonstrated the long-term pe...

Engorged and partially engorged females of Boophilus microplus were exposed to 600; 3,000; 6,000 and 30,000 infective juveniles of Steinernema carpocapsae Weiser, 1955 Santa Rosa and All strains per dish, under lab conditions. Eggs weight, pre-laying period, laying period, survival period, reproductive efficiency rate, percentage of larval eclosion and lethal concentrations of 50% and 90% (CL50 and CL90) were calculated for engorged females. In the case of partially engorged females, only egg weight, survival period and CL50 and CL90 were calculated. All biological parameters of engorged or partially engorged females were altered by exposition of S. carpocapsae infective juveniles (IJs), Santa Rosa and All strains (pFêmeas ingurgitadas e parcialmente ingurgitadas de B. microplus foram expostas a 600, 3000, 6000 e 30000 juvenis infectivos de Steinernema carpocapsae Weiser, 1955 linhagens Santa Rosa e ALL por placa, sob condições de laboratório. Foram investigados para fêmeas ingurgitadas: peso da massa de ovos, período pré-postura, período de postura, tempo de sobrevivência, índice de eficiência reprodutiva, percentual de aclosão de larvas e concentrações letais 50% e 90% (CL50 e CL90). Para fêmeas parcialmente ingurgitadas somente foram observados peso da massa de ovos, tempo de sobrevivência, CL50 e CL90. Todos os parâmetros biológicos de fêmeas ingurgitadas foram e parcialmente ingurgitadas foram alterados pela exposição a juvenis infectivos de S. carpocapsae linhagens Santa Rosa e ALL (P

Entomopathogenic nematodes (EPNs) are used for the biological control of soil insect pests worldwide and are generally applied to the soil in aqueous suspension. An alternative application method that could be especially practical and effective under certain conditions is to apply the nematode-killed insect (referred to herein as infected insect cadavers) that are placed on or in the soil and from which the nematodes emerge to seek new hosts. However, physical damage to the insect cadavers during handling and application as well as the potential detrimental impact of various soil biotic and abiotic factors could reduce the efficacy of cadaver applications. Our objective was to test the effectiveness of various protective coverings applied to Galleria mellonella insect cadavers in terms of their potential impact on the emergence and virulence of infective juveniles of the EPN Heterorhabditis baujardi LPP7, and to evaluate whether these coverings influenced cadaver removal by ants (Ectatomma spp.). The protective coveringtreatments included a commercial calcareous powder, a commercial talc powder, and gelatin capsules. The number of emerging infective juveniles (IJs) from insect cadavers formulated with talc powder (9.722 ± 1.382) and gelatin capsules (7.892 ± 1.072) was similar to the control (6.346 ± 1.311), and indicated that these coverings do not interfere with IJ emergence. However, the powdered calcareous covering significantly reduced IJ emergence. High infectivity was observed for IJs that emerged from cadavers in all treatments. Ectatomma spp. ants removed all insect cadavers from the nest entrance to a distance of 20 cm, with the exception of insect cadavers formulated in gelatin capsules, which were not removed. 2009 Elsevier Inc. All rights reserved. Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral; Argentina Fil: Dolinski, Claudia. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; Brasil Fil: Barreto, Eduardo L.S.. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; Brasil Fil: Souza, R.M.. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; Brasil

Laboratory, greenhouse, and field experiments were performed with the objective of selecting efficient indigenous strains of entomopathogenic nematodes (EPNs) from Rio Grande do Sul (RS) state, Brazil, for controlling the South American fruit fly, Anastrepha fraterculus (Wied.). Laboratory experiments were conducted in 24 well-plates filled with sterile sand and one insect per well. In greenhouse experiments, plastic trays filled with soil collected from the field were used, while in field experiments, holes were made in soil under the edge of peach tree canopies. Among 19 EPN strains tested, Heterorhabditis bacteriophora Poinar RS88 and Steinernema riobrave Cabanillas, Poinar, & Raulston RS59 resulted in higher A. fraterculus larval (pre-pupal) and pupal mortality, with LD(90) of 1630, 457 and 2851, 423 infective juveniles (IJs)/cm(2), respectively. Greenhouse experiments showed no differences in pupal mortality at 250 and 500IJs/cm(2) of either nematode. In the field, H. bacteriophora RS88 and S. riobravae RS59 sprayed individually over natural and artificially infested fruit (250IJs/cm(2)) resulted in A. fraterculus larval mortality of 51.3%, 28.1% and 20%, 24.3%, respectively. There was no significant difference in A. fraterculus pupal mortality sprayed with an aqueous suspension of either nematode; however, when using infected insect cadavers, H. bacteriophora RS88 was more efficient than S. riobrave RS59. Our results showed that H. bacteriophora RS88 was more virulent to insect larvae, with an efficient host search inside the infested fruit and control of pupae in the soil after being applied by aqueous suspension or infected cadavers.

In view of the need to combat the generalized spread of resistance in ticks to commercial acaricides, the objective of this study was to evaluate the action of entomopathogenic nematodes (Steinernema carpocapsae, strains Santa Rosa and ALL) on engorged female Anocentor nitens. Five ticks per Petri dish were exposed to concentrations of 500, 5,000, or 25,000 infective juveniles of S. carpocapsae for 72 h. After transferring the ticks to clean plates, biological parameters were analyzed. Related to strains Santa Rosa, the period of pre-oviposition (p = 0.0001), oviposition (p = 0.041), and the mass weight of eggs (p = 0.005) showed significant differences between the control group and treated group. When the strain ALL was tested, the control and treated groups differed between the periods of pre-oviposition (p = 0.001), oviposition (p = 0.001), and egg mass weight (p = 0.01). The egg mass conversion was less significant in the groups when exposed to strains Santa Rosa (p = 0.002) and ALL (p = 0.001) relative to the control. The efficacy of both entomopathogenic nematode strains used in this study was comparable to other biological control agents, showing their potential against A. nitens in the laboratory.

The present study was carried out to evaluate the action of Steinernema glaseri Santa Rosa strain and Heterorhabditis bacteriophora CCA strain as biological control agents of Boophilus microplus. Engorged females ticks were distributed on Petri dishes containing different concentrations of infective juvenile (IJ) nematodes (0, 375, 500, 750, 1,500, 2,500, 5,000 and 25,000). The data showed a reduction of approximately 90% in the eggs laid at a concentration of 5,000 S. glaseri IJs and approximately 80% at a concentration of 1,500 H. bacteriophora IJs. The female mortality increased linearly with the increase in S. glaseri concentrations. However, in the tests with H. bacteriophora this linearity was not observed. The effectiveness of the treatment with both species of entomopathogenic nematodes was compatible with other control methods. The results show the potential of S. glaseri and H. bacteriophora as biological control agents for the control of B. microplus under laboratory conditions.