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Italo Delalibera - One of the best experts on this subject based on the ideXlab platform.
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mulching with coffee husk and pulp in strawberry affects edaphic predatory mite and spider mite densities
Experimental and Applied Acarology, 2018Co-Authors: Fernanda De Cassia Neves Esteca, Italo Delalibera, Gilberto J De Moraes, Luis Rodolfo Rodrigues, Ingeborg KlingenAbstract:: Mulching of soil beds of strawberry fields is usually done with polyethylene film in southern Minas Gerais state, Brazil. This material is relatively expensive and difficult to discard after use. In some countries, mulching is done with the use of organic material that could have an advantage over the use of plastic for its easier degradation after use, and for favoring edaphic beneficial organisms. Predatory mites (especially Gamasina, Mesostigmata) may be abundant in the soil and could conceivably move to the soil surface and onto the short-growing strawberry plants at night, helping in the control or pest arthropods. The two-spotted spider mite, Tetranychus urticae Koch, is considered an important strawberry pest in that region, where the fungus Neozygites floridana (Weiser and Muma) has been found to infect it. Different mulching types could affect the incidence of this pathogen. Dehydrated coffee husk and pulp (DCHP) is a byproduct readily available in southern Minas Gerais, where could be used as organic mulching in strawberry beds. The temporary contact of that material with the soil of a patch of natural vegetation could facilitate its colonization by edaphic predatory mites helpful in the control of strawberry pests. The objective of this work was to study the effect of mulching type on the population dynamics of the two-spotted spider mite, associate mites and N. floridana, in a greenhouse and in the field. The use of DCHP increased the number of edaphic Gamasina on strawberry plants-Proctolaelaps pygmaeus (Muller) (Melicharidae) and Blattisocius dentriticus (Berlese) (Blattisociidae) were observed on strawberry leaflets, mainly in nocturnal samplings, indicating their possible daily migration from soil to plants. Lower levels of two-spotted spider mite occurred on plants from pots or soil beds mulched with DCHP instead of polyethylene film, possibly because of the slightly higher levels of mites of the family Phytoseiidae and infection by N. floridana. Adding DCHP onto the floor of natural vegetation did not result in higher diversity or levels of gamasine mites on DCHP. Complementary studies should be conducted to find ways to increase diversity and density of those organisms in strawberry beds, in an attempt to improve biological control of strawberry pests. The decision to use DCHP for mulching should also take into account other factors such as strawberry yield, costs and efficiency of weed management, to be evaluated in subsequent studies.
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prediction of sporulation and germination by the spider mite pathogenic fungus Neozygites floridana neozygitomycetes neozygitales neozygitaceae based on temperature humidity and time
Insects, 2018Co-Authors: Thiago Rodrigues De Castro, Italo Delalibera, Rafael De Andrade Moral, Clarice Garcia Borges Demetrio, Ingeborg KlingenAbstract:Neozygites floridana is a pathogenic fungus and natural enemy of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), which is an important polyphagous plant pest. The aim of this study was to reveal and predict what combination of temperature, relative humidity (RH), and time that enables and promotes primary conidia production and capilliconidia formation in N. floridana (Brazilian isolate ESALQ 1420), in both a detached leaf assay mimicking climatic conditions in the leaf boundary layer and in a semi-field experiment. In the detached leaf assay, a significant number of conidia were produced at 90% RH but the highest total number of primary conidia and proportion of capilliconidia was found at 95 and 100% RH at 25 °C. Positive temperature and RH effects were observed and conidia production was highest in the 8 to 12 h interval. The semi-field experiment showed that for a >90% probability of N. floridana sporulation, a minimum of 6 h with RH >90% and 10 h with temperatures >21 °C, or 6 h with temperatures >21 °C and 15 h with RH >90% was needed. Our study identified suitable conditions for primary- and capilliconidia production in this Brazilian N. floridana isolate. This information provides an important base for building models of a Decision Support System (DSS) where this natural enemy may be used as a tool in Integrated Pest Management (IPM) and a base for developing in vivo production systems of N. floridana.
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the effect of synthetic pesticides and sulfur used in conventional and organically grown strawberry and soybean on Neozygites floridana a natural enemy of spider mites
Pest Management Science, 2016Co-Authors: Thiago Rodrigues De Castro, Samuel Roggia, Italo Delalibera, Vitalis W Wekesa, Rafael De Andrade Moral, Clarice Garcia Borges Demetrio, Ingeborg KlingenAbstract:Background The beneficial fungus Neozygites floridana kills the two-spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana and consequently the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media, and for this reason, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana. Results Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidial germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda-cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana. Conclusion The insecticides/ acaricides abamectin and lambda-cyhalothrin at half concentrations and fenpropathrin and permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The fungicides with the active ingredients sulfur, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana. © 2015 Society of Chemical Industry
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Two-spotted spider mite and its natural enemies on strawberry grown as protected and unprotected crops in Norway and Brazil
Experimental and Applied Acarology, 2015Co-Authors: Raphael C. Castilho, Italo Delalibera, Gilberto J De Moraes, Nina Trandem, Karin Westrum, Vanessa S. Duarte, Luiz Carlos D. Rocha, Ingeborg KlingenAbstract:Cultivation of strawberry in plastic tunnels has increased considerably in Norway and in southeastern Brazil, mainly in an attempt to protect the crop from unsuitable climatic factors and some diseases as well as to allow growers to expand the traditional production season. It has been hypothesized that cultivation under tunnels could increase the incidence of one of its major pests in many countries where strawberry is cultivated, including Norway and Brazil, the two spotted spider mite, Tetranychus urticae . The objective of this study was to evaluate the effect of the use of tunnels on the incidence of T. urticae and on its natural enemies on strawberry in two ecologically contrasting regions, Norway (temperate) and southeastern Brazil (subtropical). In both countries, peak densities of T. urticae in tunnels and in the open fields were lower than economic thresholds reported in the literature. Factors determining that systematically seem to be the prevailing relatively low temperature in Norway and high relative humidity in both countries. The levels of occurrence in Norway and Brazil in 2010 were so low that regardless of any potential effect of the use of tunnel, no major differences were observed between the two cropping systems in relation to T. urticae densities. In 2009 in Norway and in 2011 in Brazil, increase in T. urticae population seemed to have been restrained mainly by rainfall in the open field and by predatory mites in the tunnels. Phytoseiids were the most numerous predatory mite group of natural occurrence on strawberry, and the prevalence was higher in Brazil, where the most abundant species on strawberry leaves were Neoseiulus anonymus and Phytoseiulus macropilis . In Norway, the most abundant naturally occurring phytoseiids on strawberry leaves were Typhlodromus ( Anthoseius ) rhenanus and Typhlodromus ( Typhlodromus ) pyri . Predatory mites were very rare in the litter samples collected in Norway. Infection rate of the pest by the fungus Neozygites floridana (Neozygitaceae) was low. The results of this work suggest that in Norway the use of tunnels might not affect the population densities of T. urticae on strawberry in years of lower temperatures. When temperature is not a limiting factor for the development of T. urticae in that country (apparently always the case in southern Brazil), strawberry cultivation in the tunnels may allow T. urticae to reach higher population levels than in open fields (because of the provided protection from the direct impact of rainfall), but natural enemies may prevent higher levels from being reached.
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confirmation of Neozygites floridana azygospore formation in two spotted spider mite tetranychus urticae in strains from tropical and temperate regions
Journal of Invertebrate Pathology, 2014Co-Authors: Karin Westrum, Italo Delalibera, Vanessa Da Silveira Duarte, Richard A Humber, Ingeborg KlingenAbstract:Abstract Neozygites floridana is an obligate fungal pathogen of mites in the family Tetranychidae and is an important natural enemy of the two-spotted spider mite (Tetranychus urticae). Until now, information about the formation of azygospores remained to be fully confirmed. In this study, we document the formation of azygospores by a Brazilian N. floridana strain and the formation of azygospores and zygospores by a Norwegian N. floridana strain, both in the host T. urticae. Evidence of both zygosporogenesis and azygosporogenesis was also found in the same individual in the Norwegian stains. Further we report the presence of immature azygospores with 1–3 nuclei for the Norwegian strains, immature resting spores (probably azygospores) with 1–8 nuclei for the Brazilian strain, and mature resting spores with 2 nuclei for both the Norwegian and the Brazilian strains (azygo- or zygospores). Our observations suggest that the immature resting spore (prespore) of both strains begins in a multinucleate condition but that the nuclear number is reduced during maturation until mature resting spore is binucleate regardless of its origin as a zygospore or azygospore.
Ingeborg Klingen - One of the best experts on this subject based on the ideXlab platform.
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Entomopathogenic fungal conidia marginally affect the behavior of the predators Orius majusculus (Hemiptera: Anthocoridae) and Phytoseiulus persimilis (Acari: Phytoseiidae) foraging for healthy Tetranychus urticae (Acari: Tetranychidae)
Experimental and Applied Acarology, 2019Co-Authors: Stine K. Jacobsen, Ingeborg Klingen, Jørgen Eilenberg, Bo Markussen, Lene SigsgaardAbstract:We determined how conidia of arthropod-pathogenic fungi on leaves affected the behavior of two predators— Orius majusculus (Hemiptera: Anthocoridae) and Phytoseiulus persimilis (Acari: Phytoseiidae)—when offered a choice between preying on two-spotted spider mites, Tetranychus urticae (Acari: Tetranychidae), in the presence or absence of infective conidia of Metarhizium brunneum (Ascomycota: Hypocreales) and Neozygites floridana (Entomophthoromycota: Neozygitaceae). The results indicate no significant relation between the presence of conidia and predator behavior. The only indication of interference is between the generalists O. majusculus and M. brunneum , with a trend towards more time spent feeding and more prey encounters turning into feeding events on leaf discs without conidia than on leaf discs with conidia. Our results show that the presence of fungal conidia does not alter the preying behavior of the predators, and using predators and fungi together is not limited by any interference between organisms in the short term.
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mulching with coffee husk and pulp in strawberry affects edaphic predatory mite and spider mite densities
Experimental and Applied Acarology, 2018Co-Authors: Fernanda De Cassia Neves Esteca, Italo Delalibera, Gilberto J De Moraes, Luis Rodolfo Rodrigues, Ingeborg KlingenAbstract:: Mulching of soil beds of strawberry fields is usually done with polyethylene film in southern Minas Gerais state, Brazil. This material is relatively expensive and difficult to discard after use. In some countries, mulching is done with the use of organic material that could have an advantage over the use of plastic for its easier degradation after use, and for favoring edaphic beneficial organisms. Predatory mites (especially Gamasina, Mesostigmata) may be abundant in the soil and could conceivably move to the soil surface and onto the short-growing strawberry plants at night, helping in the control or pest arthropods. The two-spotted spider mite, Tetranychus urticae Koch, is considered an important strawberry pest in that region, where the fungus Neozygites floridana (Weiser and Muma) has been found to infect it. Different mulching types could affect the incidence of this pathogen. Dehydrated coffee husk and pulp (DCHP) is a byproduct readily available in southern Minas Gerais, where could be used as organic mulching in strawberry beds. The temporary contact of that material with the soil of a patch of natural vegetation could facilitate its colonization by edaphic predatory mites helpful in the control of strawberry pests. The objective of this work was to study the effect of mulching type on the population dynamics of the two-spotted spider mite, associate mites and N. floridana, in a greenhouse and in the field. The use of DCHP increased the number of edaphic Gamasina on strawberry plants-Proctolaelaps pygmaeus (Muller) (Melicharidae) and Blattisocius dentriticus (Berlese) (Blattisociidae) were observed on strawberry leaflets, mainly in nocturnal samplings, indicating their possible daily migration from soil to plants. Lower levels of two-spotted spider mite occurred on plants from pots or soil beds mulched with DCHP instead of polyethylene film, possibly because of the slightly higher levels of mites of the family Phytoseiidae and infection by N. floridana. Adding DCHP onto the floor of natural vegetation did not result in higher diversity or levels of gamasine mites on DCHP. Complementary studies should be conducted to find ways to increase diversity and density of those organisms in strawberry beds, in an attempt to improve biological control of strawberry pests. The decision to use DCHP for mulching should also take into account other factors such as strawberry yield, costs and efficiency of weed management, to be evaluated in subsequent studies.
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prediction of sporulation and germination by the spider mite pathogenic fungus Neozygites floridana neozygitomycetes neozygitales neozygitaceae based on temperature humidity and time
Insects, 2018Co-Authors: Thiago Rodrigues De Castro, Italo Delalibera, Rafael De Andrade Moral, Clarice Garcia Borges Demetrio, Ingeborg KlingenAbstract:Neozygites floridana is a pathogenic fungus and natural enemy of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), which is an important polyphagous plant pest. The aim of this study was to reveal and predict what combination of temperature, relative humidity (RH), and time that enables and promotes primary conidia production and capilliconidia formation in N. floridana (Brazilian isolate ESALQ 1420), in both a detached leaf assay mimicking climatic conditions in the leaf boundary layer and in a semi-field experiment. In the detached leaf assay, a significant number of conidia were produced at 90% RH but the highest total number of primary conidia and proportion of capilliconidia was found at 95 and 100% RH at 25 °C. Positive temperature and RH effects were observed and conidia production was highest in the 8 to 12 h interval. The semi-field experiment showed that for a >90% probability of N. floridana sporulation, a minimum of 6 h with RH >90% and 10 h with temperatures >21 °C, or 6 h with temperatures >21 °C and 15 h with RH >90% was needed. Our study identified suitable conditions for primary- and capilliconidia production in this Brazilian N. floridana isolate. This information provides an important base for building models of a Decision Support System (DSS) where this natural enemy may be used as a tool in Integrated Pest Management (IPM) and a base for developing in vivo production systems of N. floridana.
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effect of light quality and light dark cycle on sporulation patterns of the mite pathogenic fungus Neozygites floridana neozygitales entomophthoromycota a natural enemy of tetranychus urticae
Journal of Invertebrate Pathology, 2016Co-Authors: Ingeborg Klingen, Karin Westrum, Maren Pindsle Holthe, A Suthaparan, Torfinn TorpAbstract:Abstract A controlled climatic chamber microcosm experiment was conducted to examine how light affects the hourly sporulation pattern of the beneficial mite pathogenic fungus Neozygites floridana during a 24 h cyclus over a period of eight consecutive days. This was done by inoculating two-spotted spider mites ( Tetranychus urticae ) with N. floridana and placing them on strawberry plants for death and sporulation. Spore (primary conidia) discharge was observed by using a spore trap. Two light regimes were tested: Plant growth light of 150 μmol m −2 s −1 for 12 h supplied by high pressure sodium lamps (HPS), followed by either; (i) 4 h of 50 μmol m −2 s −1 light with similar HPS lamps followed by 8 h darkness (full HPS light + reduced HPS light + darkness) or (ii) 4 h of 50 μmol m −2 s −1 red light followed by 8 h darkness (full HPS light + red light + darkness). A clear difference in hourly primary conidia discharge pattern between the two different light treatments was seen and a significant interaction effect between light treatment and hour in day during the 24 h cycle was observed. The primary conidia discharge peak for treatment (ii) that included red light was mainly reached within the red light hours (19:00–23:00) and the dark hours (23:00–07:00). The primary conidia discharge peak for treatment (i) with HPS light only was mainly reached within the dark hours (23:00–07:00).
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interactions between natural enemies effect of a predatory mite on transmission of the fungus Neozygites floridana in two spotted spider mite populations
Journal of Invertebrate Pathology, 2016Co-Authors: Nina Trandem, Ronny Berdinesen, J K Pell, Ingeborg KlingenAbstract:Abstract Introducing the predatory mite Phytoseiulus persimilis into two-spotted spider mite, Tetranychus urticae, populations significantly increased the proportion of T. urticae infected with the spider mite pathogen Neozygites floridana in one of two experiments. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted (20–40 T. urticae/subsample). Releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone.
Vitalis W Wekesa - One of the best experts on this subject based on the ideXlab platform.
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the effect of synthetic pesticides and sulfur used in conventional and organically grown strawberry and soybean on Neozygites floridana a natural enemy of spider mites
Pest Management Science, 2016Co-Authors: Thiago Rodrigues De Castro, Samuel Roggia, Italo Delalibera, Vitalis W Wekesa, Rafael De Andrade Moral, Clarice Garcia Borges Demetrio, Ingeborg KlingenAbstract:Background The beneficial fungus Neozygites floridana kills the two-spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana and consequently the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media, and for this reason, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana. Results Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidial germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda-cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana. Conclusion The insecticides/ acaricides abamectin and lambda-cyhalothrin at half concentrations and fenpropathrin and permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The fungicides with the active ingredients sulfur, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana. © 2015 Society of Chemical Industry
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the effects of photoperiod and light intensity on the sporulation of brazilian and norwegian isolates of Neozygites floridana
Journal of Invertebrate Pathology, 2013Co-Authors: Thiago Rodrigues De Castro, Italo Delalibera, Vitalis W Wekesa, Rafael De Andrade Moral, Clarice Garcia Borges Demetrio, Ingeborg KlingenAbstract:The objective of this study was to determine the effects of light intensity and duration (photoperiod) on the sporulation (discharge of primary conidia) and conidia germination (from non-infective primary conidia to infective capilliconidia) of Neozygites floridana isolates from Tetranychus urticae originating from Norway and Brazil. Two light intensities (40 and 208 μmol m−2 s−1), three photoperiods (24 h of continuous light (24 h D), 12 h of darkness followed by 12 h of light (12 h D: 12 h L) and 24 h of continuous darkness (24 h D)) and two temperatures (18 °C and 23 °C) were tested. The fungus produced similar amounts of primary conidia and capilliconidia at 12 h D:12 h and 24 h D, indicating that the fungus discharges almost all of its conidia during the first 12 h of darkness. Light had less of an effect on the production of primary conidia than on capilliconidia formation. At 24 h L, capilliconidia formation was significantly lower for all tested light intensities, temperatures and isolates compared to 12 h D:12 h L and 24 h D. At both light intensities, 24 h L resulted in a significantly lower capilliconidia formation for the Norwegian isolate compared to the Brazilian isolate. Our data suggest that, even though 24 h L reduced sporulation, some capilliconidia formation may occur at the low light intensities found on the underside of strawberry leaves during parts of the day as well as the top of a non-shaded strawberry leaf during the dim evening and morning hours in the tropics and during the dim, long summer days in temperate regions.
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the effect of host plants on tetranychus evansi tetranychus urticae acari tetranychidae and on their fungal pathogen Neozygites floridana entomophthorales neozygitaceae
Journal of Invertebrate Pathology, 2011Co-Authors: Vitalis W Wekesa, Ingeborg Klingen, S Vital, R A Silva, Edwin M M Ortega, Italo DelaliberaAbstract:In a series of tritrophic-level interaction experiments, the effect of selected host plants of the spider mites, Tetranychus evansi and Tetranychus urticae, on Neozygites floridana was studied by evaluating the attachment of capilliconidia, presence of hyphal bodies in the infected mites, mortality from fungal infection, mummification and sporulation from fungus-killed mite cadavers. Host plants tested for T. evansi were tomato, cherry tomato, eggplant, nightshade, and pepper while host plants tested for T. urticae were strawberry, jack bean, cotton and Gerbera. Oviposition rate of the mites on each plant was determined to infer host plant suitability while host-switching determined antibiosis effect on fungal activity. T. evansi had a high oviposition on eggplant, tomato and nightshade but not on cherry tomato and pepper. T. urticae on jack bean resulted in a higher oviposition than on strawberry, cotton and Gerbera. Attachment of capilliconidia to the T. evansi body, presence of hyphal bodies in infected T. evansi and mortality from fungal infection were significantly higher on pepper, nightshade and tomato. The highest level of T. evansi mummification was observed on tomato. T. evansi cadavers from tomato and eggplant produced more primary conidia than those from cherry tomato, nightshade and pepper. Switching N. floridana infected T. evansi from one of five Solanaceous host plants to tomato had no prominent effect on N. floridana performance. For T. urticae, strawberry and jack bean provided the best N. floridana performance when considering all measured parameters. Strawberry also had the highest primary conidia production. This study shows that performance of N. floridana can vary with host plants and may be an important factor for the development of N. floridana epizootics.
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effect of temperature on sporulation of Neozygites floridana isolates from different climates and their virulence against the tomato red spider mite tetranychus evansi
Journal of Invertebrate Pathology, 2010Co-Authors: Vitalis W Wekesa, Gilberto J De Moraes, Edwin M M Ortega, Italo DelaliberaAbstract:Abstract The fungal pathogen Neozygites floridana Weiser and Muma has been evaluated as a classical biological candidate for introduction into Africa against the invasive tomato red spider mite Tetranychus evansi Baker and Pritchard. In this study, the effect of temperature on sporulation, germination and virulence of three isolates of N. floridana collected from T. evansi in three climatically distinct regions of Brazil and Argentina was determined. Six constant temperatures of 13 °C, 17 °C, 21 °C, 25 °C, 29 °C and 33 °C were tested for their effect on the ability of the three fungal isolates to sporulate, germinate and kill the mites. Six alternating-temperature regimes of 17–13 °C, 21–13 °C, 29–13 °C, 33–13 °C, 33–23 °C, 33–28 °C under a 12 h photophase were also tested to estimate virulence of the three isolates against T. evansi. The Vipos isolate discharged more conidia than isolates from Recife or Piracicaba at all temperatures and sporulation was strongly temperature dependent. Optimal sporulation rates were observed at 25 °C while optimal germination rates were observed at 25 °C and 29 °C. At 29 °C, the shortest mean survival time of T. evansi (3.16 days, 95% CI of 3.05–3.27) was observed for the isolate from Vipos, while the longest LT50 (3.47 days, 95% CI 3.34–3.59) was observed for the isolate from Piracicaba. Mortality of mites increased as the differences between alternating day and night temperatures increased from 8 °C (21–13 °C), to 10 °C (33–23 °C), to 16 °C (29–13 °C), with smallest and highest temperature differences of 4 °C (17–13 °C) and 20 °C (33–13 °C), both producing low mortalities. The overall results suggest that the Vipos isolate is better adapted to a wider range of temperatures than the other isolates tested.
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impact of natural epizootics of the fungal pathogen Neozygites floridana zygomycetes entomophthorales on population dynamics of tetranychus evansi acari tetranychidae in tomato and nightshade
Biological Control, 2009Co-Authors: Vanessa Da Silveira Duarte, Vitalis W Wekesa, R A Silva, F B Rizzato, Carlos Tadeu Dos Santos Dias, Italo DelaliberaAbstract:The tomato red spider mite, Tetranychus evansi (Acari: Tetranychidae) was recently introduced in Africa and Europe, where there is an increasing interest in using natural enemies to control this pest on solanaceous crops. Two promising candidates for the control of T. evansi were identified in South America, the fungal pathogen, Neozygites floridana and the predatory mite Phytoseiulus longipes. In this study, population dynamics of T. evansi and its natural enemies together with the influence of environmental conditions on these organisms were evaluated during four crop cycles in the field and in a protected environment on nightshade and tomato plants with and without application of chemical pesticides. N. floridana was the only natural enemy found associated with T. evansi in the four crop cycles under protected environment but only in the last crop cycle in the field. In the treatments where the fungus appeared, reduction of mite populations was drastic. N. floridana appeared in tomato plants even when the population density of T. evansi was relatively low (less than 10 mites/3.14 cm 2 of leaf area) and even at this low population density, the fungus maintained infection rates greater than 50%. The application of pesticides directly affected the fungus by delaying epizootic initiation and contributing to lower infection rates than unsprayed treatments. Rainfalls did not have an apparent impact on mite populations. These results indicate that the pathogenic fungus, N. floridana can play a significant role in the population dynamics of T. evansi, especially under protected environment, and has the potential to control this pest in classical biological control programs.
Karin Westrum - One of the best experts on this subject based on the ideXlab platform.
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effect of light quality and light dark cycle on sporulation patterns of the mite pathogenic fungus Neozygites floridana neozygitales entomophthoromycota a natural enemy of tetranychus urticae
Journal of Invertebrate Pathology, 2016Co-Authors: Ingeborg Klingen, Karin Westrum, Maren Pindsle Holthe, A Suthaparan, Torfinn TorpAbstract:Abstract A controlled climatic chamber microcosm experiment was conducted to examine how light affects the hourly sporulation pattern of the beneficial mite pathogenic fungus Neozygites floridana during a 24 h cyclus over a period of eight consecutive days. This was done by inoculating two-spotted spider mites ( Tetranychus urticae ) with N. floridana and placing them on strawberry plants for death and sporulation. Spore (primary conidia) discharge was observed by using a spore trap. Two light regimes were tested: Plant growth light of 150 μmol m −2 s −1 for 12 h supplied by high pressure sodium lamps (HPS), followed by either; (i) 4 h of 50 μmol m −2 s −1 light with similar HPS lamps followed by 8 h darkness (full HPS light + reduced HPS light + darkness) or (ii) 4 h of 50 μmol m −2 s −1 red light followed by 8 h darkness (full HPS light + red light + darkness). A clear difference in hourly primary conidia discharge pattern between the two different light treatments was seen and a significant interaction effect between light treatment and hour in day during the 24 h cycle was observed. The primary conidia discharge peak for treatment (ii) that included red light was mainly reached within the red light hours (19:00–23:00) and the dark hours (23:00–07:00). The primary conidia discharge peak for treatment (i) with HPS light only was mainly reached within the dark hours (23:00–07:00).
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Two-spotted spider mite and its natural enemies on strawberry grown as protected and unprotected crops in Norway and Brazil
Experimental and Applied Acarology, 2015Co-Authors: Raphael C. Castilho, Italo Delalibera, Gilberto J De Moraes, Nina Trandem, Karin Westrum, Vanessa S. Duarte, Luiz Carlos D. Rocha, Ingeborg KlingenAbstract:Cultivation of strawberry in plastic tunnels has increased considerably in Norway and in southeastern Brazil, mainly in an attempt to protect the crop from unsuitable climatic factors and some diseases as well as to allow growers to expand the traditional production season. It has been hypothesized that cultivation under tunnels could increase the incidence of one of its major pests in many countries where strawberry is cultivated, including Norway and Brazil, the two spotted spider mite, Tetranychus urticae . The objective of this study was to evaluate the effect of the use of tunnels on the incidence of T. urticae and on its natural enemies on strawberry in two ecologically contrasting regions, Norway (temperate) and southeastern Brazil (subtropical). In both countries, peak densities of T. urticae in tunnels and in the open fields were lower than economic thresholds reported in the literature. Factors determining that systematically seem to be the prevailing relatively low temperature in Norway and high relative humidity in both countries. The levels of occurrence in Norway and Brazil in 2010 were so low that regardless of any potential effect of the use of tunnel, no major differences were observed between the two cropping systems in relation to T. urticae densities. In 2009 in Norway and in 2011 in Brazil, increase in T. urticae population seemed to have been restrained mainly by rainfall in the open field and by predatory mites in the tunnels. Phytoseiids were the most numerous predatory mite group of natural occurrence on strawberry, and the prevalence was higher in Brazil, where the most abundant species on strawberry leaves were Neoseiulus anonymus and Phytoseiulus macropilis . In Norway, the most abundant naturally occurring phytoseiids on strawberry leaves were Typhlodromus ( Anthoseius ) rhenanus and Typhlodromus ( Typhlodromus ) pyri . Predatory mites were very rare in the litter samples collected in Norway. Infection rate of the pest by the fungus Neozygites floridana (Neozygitaceae) was low. The results of this work suggest that in Norway the use of tunnels might not affect the population densities of T. urticae on strawberry in years of lower temperatures. When temperature is not a limiting factor for the development of T. urticae in that country (apparently always the case in southern Brazil), strawberry cultivation in the tunnels may allow T. urticae to reach higher population levels than in open fields (because of the provided protection from the direct impact of rainfall), but natural enemies may prevent higher levels from being reached.
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fatal attraction male spider mites prefer females killed by the mite pathogenic fungus Neozygites floridana
Journal of Invertebrate Pathology, 2015Co-Authors: Nina Trandem, Karin Westrum, Upendra Raj Bhattarai, Geir Kjolberg Knudsen, Ingeborg KlingenAbstract:Exploring prospective mates can be risky. Males of the spider mite Tetranychus urticae approach and guard immobile (quiescent) female nymphs to increase their chances of fathering offspring, this being a first-male sperm priority species. We investigated the behaviour of male T. urticae towards females killed by the mite pathogenic fungus Neozygites floridana, letting them choose between a fungal killed and a healthy quiescent female. The dead female (called cadaver) was in one of three stages: (1) non-sporulating; (2) sporulating with primary conidia (non-infective); (3) surrounded/partly covered by secondary capilliconidia (infective). When the cadaver was in stage 1 or 2, males were significantly more often observed near the cadaver than near the healthy female. When the cadaver was in stage 3 (infective capilliconidia), males preferred the vicinity of healthy females. The frequency of two male behaviours, touching and guarding, was also recorded. Touching the cadaver tended to decrease as cadaver developed, whereas touching the healthy females increased. Guarding of non-sporulating cadavers and healthy females was equally common, while guarding of sporulating cadavers was only observed once (stage 2) or not at all (stage 3). To differentiate between the effect of fungal infection and sex, we also let males choose between a non-sporulating cadaver of each sex. Males then preferred to approach the female cadaver. Touching behaviour followed the same pattern, and guarding of male cadavers was not observed. Our results indicate that T. urticae males are more attracted to non-infective female cadavers than to healthy females, only detecting their mistake when very close. Moreover, males approach and explore cadavers surrounded by infective conidia. Whether the results of host manipulation by the pathogen or just sensory constraints in the host, this inability to detect unsuitable and indeed infective mates promotes transmission of the pathogen.
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confirmation of Neozygites floridana azygospore formation in two spotted spider mite tetranychus urticae in strains from tropical and temperate regions
Journal of Invertebrate Pathology, 2014Co-Authors: Karin Westrum, Italo Delalibera, Vanessa Da Silveira Duarte, Richard A Humber, Ingeborg KlingenAbstract:Abstract Neozygites floridana is an obligate fungal pathogen of mites in the family Tetranychidae and is an important natural enemy of the two-spotted spider mite (Tetranychus urticae). Until now, information about the formation of azygospores remained to be fully confirmed. In this study, we document the formation of azygospores by a Brazilian N. floridana strain and the formation of azygospores and zygospores by a Norwegian N. floridana strain, both in the host T. urticae. Evidence of both zygosporogenesis and azygosporogenesis was also found in the same individual in the Norwegian stains. Further we report the presence of immature azygospores with 1–3 nuclei for the Norwegian strains, immature resting spores (probably azygospores) with 1–8 nuclei for the Brazilian strain, and mature resting spores with 2 nuclei for both the Norwegian and the Brazilian strains (azygo- or zygospores). Our observations suggest that the immature resting spore (prespore) of both strains begins in a multinucleate condition but that the nuclear number is reduced during maturation until mature resting spore is binucleate regardless of its origin as a zygospore or azygospore.
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abiotic and biotic factors affecting resting spore formation in the mite pathogen Neozygites floridana
International Journal of Microbiology, 2013Co-Authors: Vanessa Da Silveira Duarte, Ingeborg Klingen, Karin Westrum, Ana Elizabete Lopes Ribeiro, Manoel Guedes Correa Gondim, Italo DelaliberaAbstract:Neozygites floridana is an obligate mite pathogenic fungus in the Entomophthoromycota. It has been suggested that resting spores of this fungus are produced as a strategy to survive adverse conditions. In the present study, possible mechanisms involved in the regulation of resting spore formation were investigated in the hosts Tetranychus urticae and Tetranychus evansi. Abiotic and biotic factors mimicking conditions that we, based on earlier field studies, thought might induce resting spores in temperate and tropical regions were tested with isolates from Norway and Brazil. A total of 42 combinations of conditions were tested, but only one induced the formation of a high number of resting spores in only one isolate. The Brazilian isolate ESALQ1420 produced a large number of resting spores (51.5%) in T. urticae at a temperature of 11°C, photoperiod of 10L:14D, and light intensity of 42–46 (μmol m−2 s−1) on nonsenescent plants (nondiapausing females). Resting spores of the Brazilian N. floridana isolate ESALQ1421 were found at very low levels (up to 1.0%). Small percentages of T. urticae with resting spores (0–5.0%) were found for the Norwegian isolate NCRI271/04 under the conditions tested. The percentages of resting spores found for the Norwegian isolate in our laboratory studies are similar to the prevalence reported in earlier field studies.
Gilberto J De Moraes - One of the best experts on this subject based on the ideXlab platform.
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mulching with coffee husk and pulp in strawberry affects edaphic predatory mite and spider mite densities
Experimental and Applied Acarology, 2018Co-Authors: Fernanda De Cassia Neves Esteca, Italo Delalibera, Gilberto J De Moraes, Luis Rodolfo Rodrigues, Ingeborg KlingenAbstract:: Mulching of soil beds of strawberry fields is usually done with polyethylene film in southern Minas Gerais state, Brazil. This material is relatively expensive and difficult to discard after use. In some countries, mulching is done with the use of organic material that could have an advantage over the use of plastic for its easier degradation after use, and for favoring edaphic beneficial organisms. Predatory mites (especially Gamasina, Mesostigmata) may be abundant in the soil and could conceivably move to the soil surface and onto the short-growing strawberry plants at night, helping in the control or pest arthropods. The two-spotted spider mite, Tetranychus urticae Koch, is considered an important strawberry pest in that region, where the fungus Neozygites floridana (Weiser and Muma) has been found to infect it. Different mulching types could affect the incidence of this pathogen. Dehydrated coffee husk and pulp (DCHP) is a byproduct readily available in southern Minas Gerais, where could be used as organic mulching in strawberry beds. The temporary contact of that material with the soil of a patch of natural vegetation could facilitate its colonization by edaphic predatory mites helpful in the control of strawberry pests. The objective of this work was to study the effect of mulching type on the population dynamics of the two-spotted spider mite, associate mites and N. floridana, in a greenhouse and in the field. The use of DCHP increased the number of edaphic Gamasina on strawberry plants-Proctolaelaps pygmaeus (Muller) (Melicharidae) and Blattisocius dentriticus (Berlese) (Blattisociidae) were observed on strawberry leaflets, mainly in nocturnal samplings, indicating their possible daily migration from soil to plants. Lower levels of two-spotted spider mite occurred on plants from pots or soil beds mulched with DCHP instead of polyethylene film, possibly because of the slightly higher levels of mites of the family Phytoseiidae and infection by N. floridana. Adding DCHP onto the floor of natural vegetation did not result in higher diversity or levels of gamasine mites on DCHP. Complementary studies should be conducted to find ways to increase diversity and density of those organisms in strawberry beds, in an attempt to improve biological control of strawberry pests. The decision to use DCHP for mulching should also take into account other factors such as strawberry yield, costs and efficiency of weed management, to be evaluated in subsequent studies.
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Two-spotted spider mite and its natural enemies on strawberry grown as protected and unprotected crops in Norway and Brazil
Experimental and Applied Acarology, 2015Co-Authors: Raphael C. Castilho, Italo Delalibera, Gilberto J De Moraes, Nina Trandem, Karin Westrum, Vanessa S. Duarte, Luiz Carlos D. Rocha, Ingeborg KlingenAbstract:Cultivation of strawberry in plastic tunnels has increased considerably in Norway and in southeastern Brazil, mainly in an attempt to protect the crop from unsuitable climatic factors and some diseases as well as to allow growers to expand the traditional production season. It has been hypothesized that cultivation under tunnels could increase the incidence of one of its major pests in many countries where strawberry is cultivated, including Norway and Brazil, the two spotted spider mite, Tetranychus urticae . The objective of this study was to evaluate the effect of the use of tunnels on the incidence of T. urticae and on its natural enemies on strawberry in two ecologically contrasting regions, Norway (temperate) and southeastern Brazil (subtropical). In both countries, peak densities of T. urticae in tunnels and in the open fields were lower than economic thresholds reported in the literature. Factors determining that systematically seem to be the prevailing relatively low temperature in Norway and high relative humidity in both countries. The levels of occurrence in Norway and Brazil in 2010 were so low that regardless of any potential effect of the use of tunnel, no major differences were observed between the two cropping systems in relation to T. urticae densities. In 2009 in Norway and in 2011 in Brazil, increase in T. urticae population seemed to have been restrained mainly by rainfall in the open field and by predatory mites in the tunnels. Phytoseiids were the most numerous predatory mite group of natural occurrence on strawberry, and the prevalence was higher in Brazil, where the most abundant species on strawberry leaves were Neoseiulus anonymus and Phytoseiulus macropilis . In Norway, the most abundant naturally occurring phytoseiids on strawberry leaves were Typhlodromus ( Anthoseius ) rhenanus and Typhlodromus ( Typhlodromus ) pyri . Predatory mites were very rare in the litter samples collected in Norway. Infection rate of the pest by the fungus Neozygites floridana (Neozygitaceae) was low. The results of this work suggest that in Norway the use of tunnels might not affect the population densities of T. urticae on strawberry in years of lower temperatures. When temperature is not a limiting factor for the development of T. urticae in that country (apparently always the case in southern Brazil), strawberry cultivation in the tunnels may allow T. urticae to reach higher population levels than in open fields (because of the provided protection from the direct impact of rainfall), but natural enemies may prevent higher levels from being reached.
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New records of Tetranychus evansi and associated natural enemies in northern Argentina.
Systematic & Applied Acarology, 2010Co-Authors: Alberto Daniel Guanilo, Gilberto J De Moraes, Silvana Toledo, M. KnappAbstract:Abstract The tomato red spider mite, Tetranychus evansi Baker and Pritchard, has been considered as a threat to tomato production in some countries. Limited efforts have been dedicated to search for this mite and its natural enemies in Argentina. The objective of this study was to further study the distribution of T. evansi and the occurrence of associated natural enemies of this mite in the northern part of that country. The survey was conducted in the provinces of Chaco, Corrientes, Entre Rios, Santiago del Estero, Salta and Tucuman. A total of 1959 mites belonging to 57 species was found. Tetranychus evansi was found in the latter 5 provinces, which are located along the borders to Bolivia, Brazil, Paraguay and Uruguay. Euseius concordis (Chant) (Phytoseiidae) was the most abundant and frequent predator in this study; other predators were much less abundant and frequent. None of the predators found seem to be promising as a control agent of T. evansi. The pathogenic fungus Neozygites floridana Weiser a...
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effect of temperature on sporulation of Neozygites floridana isolates from different climates and their virulence against the tomato red spider mite tetranychus evansi
Journal of Invertebrate Pathology, 2010Co-Authors: Vitalis W Wekesa, Gilberto J De Moraes, Edwin M M Ortega, Italo DelaliberaAbstract:Abstract The fungal pathogen Neozygites floridana Weiser and Muma has been evaluated as a classical biological candidate for introduction into Africa against the invasive tomato red spider mite Tetranychus evansi Baker and Pritchard. In this study, the effect of temperature on sporulation, germination and virulence of three isolates of N. floridana collected from T. evansi in three climatically distinct regions of Brazil and Argentina was determined. Six constant temperatures of 13 °C, 17 °C, 21 °C, 25 °C, 29 °C and 33 °C were tested for their effect on the ability of the three fungal isolates to sporulate, germinate and kill the mites. Six alternating-temperature regimes of 17–13 °C, 21–13 °C, 29–13 °C, 33–13 °C, 33–23 °C, 33–28 °C under a 12 h photophase were also tested to estimate virulence of the three isolates against T. evansi. The Vipos isolate discharged more conidia than isolates from Recife or Piracicaba at all temperatures and sporulation was strongly temperature dependent. Optimal sporulation rates were observed at 25 °C while optimal germination rates were observed at 25 °C and 29 °C. At 29 °C, the shortest mean survival time of T. evansi (3.16 days, 95% CI of 3.05–3.27) was observed for the isolate from Vipos, while the longest LT50 (3.47 days, 95% CI 3.34–3.59) was observed for the isolate from Piracicaba. Mortality of mites increased as the differences between alternating day and night temperatures increased from 8 °C (21–13 °C), to 10 °C (33–23 °C), to 16 °C (29–13 °C), with smallest and highest temperature differences of 4 °C (17–13 °C) and 20 °C (33–13 °C), both producing low mortalities. The overall results suggest that the Vipos isolate is better adapted to a wider range of temperatures than the other isolates tested.
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interactions of two natural enemies of tetranychus evansi the fungal pathogen Neozygites floridana zygomycetes entomophthorales and the predatory mite phytoseiulus longipes acari phytoseiidae
Biological Control, 2007Co-Authors: Vitalis W Wekesa, M. Knapp, Gilberto J De Moraes, Italo DelaliberaAbstract:Tetranychus evansi is an exotic pest of Solanaceous crops in Africa discovered in Zimbabwe in 1979. Two natural enemies, the predatory mite Phytoseiulus longipes and the fungal pathogen Neozygites floridana are important causes of mortality in T. evansi populations in Brazil. The first part of this study assessed the effects of N. floridana on predation and oviposition of P. longipes fed on N. floridana infected T. evansi and T. urticae. No N. floridana hyphal bodies were found in P. longipes after this feeding, demonstrating that N. floridana is not pathogenic to P. longipes and does not affect its oviposition. The second part of the study investigated the time spent on searching for and consuming of eggs on leaf discs with and without N. floridana capilliconidia. Both the searching and the feeding time on the first egg were similar on leaf discs with and without capilliconidia. When P. longipes was offered the choice of feeding on eggs on leaf discs with or without capilliconidia, the numbers of eggs consumed were not different. The only N. floridana effect observed on P. longipes was reduced egg predation. In addition, increased time spent grooming on leaf discs with capilliconidia was observed. P. longipes was efficient in removing most capilliconidia attached to the body through self-grooming behavior. This suggests that although the predator did not avoid areas with capilliconidia, it detected and removed most capilliconidia attached to the body. Increased grooming may account for the lower egg predation rates.