Thainá Rodrigues Santos

Bio: Thainá Rodrigues Santos is an academic researcher from Universidade Federal de Goiás. The author has contributed to research in topics: Metarhizium anisopliae & Biological pest control. The author has an hindex of 2, co-authored 3 publications receiving 7 citations.

Relative humidity impacts development and activity against Aedes aegypti adults by granular formulations of Metarhizium humberi microsclerotia.

Abstract: The impact of ambient relative humidity (RH) on conidial production of Metarhizium humberi IP 46 microsclerotia (MS) formulated in pellets or granules was investigated, and a promising granular formulation was tested against Aedes aegypti adults to confirm its efficacy. Microcrystalline cellulose (MC) and diatomaceous earth (DE) or a combination of vermiculite (VE), DE and silicon dioxide (SD) were tested as carriers in granular formulations containing MS. A range of 93-96.5% RH was critical for fungal development, and at least 96.5-98.5% RH was required for high conidial production on pellets or granules. Conidial production was clearly higher on pellets and granules prepared with VE than MC as the main carrier. VE granules containing MS were highly active against A. aegypti adults. Most mosquitoes were killed within 6 days after treatment regardless of the exposure time of adults to the formulation (1 min-24 h) or ambient humidity (75 or >98%). Production of conidia on dead adults varied between 7.3 × 106 and 2.2 × 107 conidia/individual, when exposed to MS granules for 12 h and 1 min, respectively. Granular formulations containing VE as the main carrier and MS as the active ingredient of M. humberi have strong potential for use against A. aegypti. KEY POINTS: • High conidial production on granular microsclerotial formulations at >96.5% RH • Vermiculite is more appropriate as a carrier than microcrystalline cellulose • Granules with IP 46 microsclerotia are highly active against Aedes aegypti adults.

Inorganic pellets containing microsclerotia of Metarhizium anisopliae: a new technological platform for the biological control of the cattle tick Rhipicephalus microplus

Abstract: This study was sought to devise pellets containing inorganic materials and microsclerotia of Metarhizium anisopliae strain IP 119 for biological control of Rhipicephalus microplus, the most economically important tick in Brazilian cattle industry. In addition, we evaluated the storage stability of the pellets, their tolerance to ultraviolet radiation (UV-B), and efficacy against ticks under laboratory conditions. Fungal microsclerotia were produced by liquid culture fermentation and mixed with pre-selected inorganic matrices: vermiculite powder, diatomaceous earth, and colloidal silicon dioxide (78:20:2, w/w/w). The microsclerotial pellets were then prepared by a two-stage process involving extrusion and spheronization. Pellet size averaged 525.53 ± 7.74 μm, with a sphericity index of 0.72 ± 0.01, while biomass constituents did not affect the wet mass properties. Conidial production from microsclerotial pellets upon rehydration ranged from 1.85 × 109 to 1.97 × 109 conidia g−1 with conidial viability ≥ 93%. Conidial production from pellets stored at 4 °C was invariable for up to 21 days. Unformulated microsclerotia and microsclerotial pellets were extremely tolerant to UV-B compared with aerial conidia. Engorged tick females exposed to conidia from sporulated pellets applied to soil samples and upon optimal rehydration exhibited shorter oviposition time length, shorter life span, and reduced number of hatched larvae. In summary, microsclerotial pellets of M. anisopliae IP 119 effectively suppressed R. microplus and showed outstanding UV-B tolerance in laboratory tests. Prospectively, this formulation prototype is promising for targeting the non-parasitic stage of this tick on outdoor pasture fields and may offer a novel mycoacaricide for its sustainable management. • Pellets with microsclerotia and inorganic materials are innovative for tick control. • Metarhizium microsclerotia show superior UV-B tolerance in relation to conidia. • Pellets of Metarhizium microsclerotia produce infective conidia against ticks.

composição e processo de preparação multiparticulada de natureza sólida contendo microescleródios de metarhizium anisopliae para controle de artrópodes-praga de importância na saúde humana, veterinária e na agropecuária e seus usos

Abstract: composicao e processo de preparacao multiparticulada de natureza solida contendo microesclerodios de metarhizium anisopliae para controle de artropodes-praga de importância na saude humana, veterinaria e na agropecuaria e seus usos. a presente invencao descreve formulacoes e processos de obtencao de sistemas solidos multiparticulados contendo microesclerodios de metarhizium anisopliae para o controle biologico de artropodes-praga, especialmente de rhipicephalus microplus (carrapato-do-boi). essa forma de apresentacao pode facilitar a aplicacao dos agentes biologicos no campo, tornando-a mais reprodutivel e efetiva, alem de mais segura. os fungos formulados se apresentam com viabilidade estavel sob refrigeracao e os bioensaios comprovam sua efetividade. dessa forma, as formulacoes descritas aqui devem possibilitar um controle biologico mais eficaz e mais seguro que as formulacoes existentes atualmente.

Relative humidity impacts development and activity against Aedes aegypti adults by granular formulations of Metarhizium humberi microsclerotia.

Abstract: The impact of ambient relative humidity (RH) on conidial production of Metarhizium humberi IP 46 microsclerotia (MS) formulated in pellets or granules was investigated, and a promising granular formulation was tested against Aedes aegypti adults to confirm its efficacy. Microcrystalline cellulose (MC) and diatomaceous earth (DE) or a combination of vermiculite (VE), DE and silicon dioxide (SD) were tested as carriers in granular formulations containing MS. A range of 93-96.5% RH was critical for fungal development, and at least 96.5-98.5% RH was required for high conidial production on pellets or granules. Conidial production was clearly higher on pellets and granules prepared with VE than MC as the main carrier. VE granules containing MS were highly active against A. aegypti adults. Most mosquitoes were killed within 6 days after treatment regardless of the exposure time of adults to the formulation (1 min-24 h) or ambient humidity (75 or >98%). Production of conidia on dead adults varied between 7.3 × 106 and 2.2 × 107 conidia/individual, when exposed to MS granules for 12 h and 1 min, respectively. Granular formulations containing VE as the main carrier and MS as the active ingredient of M. humberi have strong potential for use against A. aegypti. KEY POINTS: • High conidial production on granular microsclerotial formulations at >96.5% RH • Vermiculite is more appropriate as a carrier than microcrystalline cellulose • Granules with IP 46 microsclerotia are highly active against Aedes aegypti adults.

A Review of Commercial Metarhizium- and Beauveria-Based Biopesticides for the Biological Control of Ticks in the USA

Abstract: Simple Summary Microbial biopesticides containing entomopathogenic fungi have potential in tick management. In this review, we compiled a comprehensive list of the use of commercialized Metarhizium and Beauveria-based biopesticides in the USA that have been tested against ixodid ticks under laboratory and field conditions and when used as a part of integrated tick management. Despite considerable progress in the development of fungal biopesticides over the past 20 years, the establishment of commercial products available for use against ticks continues to be slow. There is a need for the development of sustainable, nonchemical tick management strategies. Until efficacious fungus-based products become more available, tick management will rely primarily on synthetic chemical acaricides, with natural-product acaricides as the alternative. Abstract There is a need for the development of sustainable, nonchemical tick management strategies. Mycoacaricide and mycoinsecticide product development worldwide has focused primarily on fungi in the genera Beauveria (Hypocreales: Cordycipitaceae) and Metarhizium (Hypocreales: Clavicipitaceae). Microbial biopesticides containing entomopathogenic fungi have potential in tick management. However, despite considerable progress in the development of fungal biopesticides over the past 20 years, the establishment of commercial products available for use against ticks continues to be slow. We reviewed published scientific literature and compiled a comprehensive list of reports of the effectiveness of commercial biopesticides based on the fungal genera Metarhizium and Beauveria and registered for use in the USA against ixodid ticks under laboratory and field conditions. We also report on results when these biopesticides were used as a part of integrated tick management. Until efficacious fungus-based products become more available, tick management will rely primarily on synthetic chemical acaricides, with natural-product acaricides as the alternative.

Inorganic pellets containing microsclerotia of Metarhizium anisopliae: a new technological platform for the biological control of the cattle tick Rhipicephalus microplus

Abstract: This study was sought to devise pellets containing inorganic materials and microsclerotia of Metarhizium anisopliae strain IP 119 for biological control of Rhipicephalus microplus, the most economically important tick in Brazilian cattle industry. In addition, we evaluated the storage stability of the pellets, their tolerance to ultraviolet radiation (UV-B), and efficacy against ticks under laboratory conditions. Fungal microsclerotia were produced by liquid culture fermentation and mixed with pre-selected inorganic matrices: vermiculite powder, diatomaceous earth, and colloidal silicon dioxide (78:20:2, w/w/w). The microsclerotial pellets were then prepared by a two-stage process involving extrusion and spheronization. Pellet size averaged 525.53 ± 7.74 μm, with a sphericity index of 0.72 ± 0.01, while biomass constituents did not affect the wet mass properties. Conidial production from microsclerotial pellets upon rehydration ranged from 1.85 × 109 to 1.97 × 109 conidia g−1 with conidial viability ≥ 93%. Conidial production from pellets stored at 4 °C was invariable for up to 21 days. Unformulated microsclerotia and microsclerotial pellets were extremely tolerant to UV-B compared with aerial conidia. Engorged tick females exposed to conidia from sporulated pellets applied to soil samples and upon optimal rehydration exhibited shorter oviposition time length, shorter life span, and reduced number of hatched larvae. In summary, microsclerotial pellets of M. anisopliae IP 119 effectively suppressed R. microplus and showed outstanding UV-B tolerance in laboratory tests. Prospectively, this formulation prototype is promising for targeting the non-parasitic stage of this tick on outdoor pasture fields and may offer a novel mycoacaricide for its sustainable management. • Pellets with microsclerotia and inorganic materials are innovative for tick control. • Metarhizium microsclerotia show superior UV-B tolerance in relation to conidia. • Pellets of Metarhizium microsclerotia produce infective conidia against ticks.

Efficacy of focal applications of a mycoinsecticide to control Aedes aegypti in Central Brazil.

Abstract: Entomopathogenic fungi can achieve important innovative outcomes for integrated mosquito control especially of Aedes aegypti, the key vector of arboviruses to humans in the tropics and subtropics. This study sought to design and to develop a simple dissemination device to attract and to infect gravid A. aegypti adults with a granular formulation of the ascomycete Metarhizium humberi IP 46, and to validate this device in the laboratory as well as in semi-field and field conditions. Hydrogel (polyacrylamide potassium polyacrylate) was confirmed to be a suitable substitute for water used in the device that attracted gravid females under field conditions. Females laid eggs on black polyethylene terephthalate carpet fixed in the device that also proved to be a suitable substrate for a granular formulation of fungal microsclerotia and/or conidia. The plastic device (29.5 cm high) was divided into a lower closed compartment with a water reservoir and an upper, laterally open but covered compartment with continuously hydrated gel and the fungal formulation attached to the carpet. The uppermost compartment permitted free circulation of mosquito adults. The device attracted both male and female A. aegypti. The fungal formulations of IP 46 propagules tested in the device were effective against adults in laboratory, semi-field, and field settings. Findings in the laboratory, semi-field, and especially in field conditions strengthen the value and utility of this innovative device for focal applications of a mycoinsecticide against this important mosquito vector. Key points • Low-cost and simple disseminating device for focal control of Aedes aegypti. • Granulized Metarhizium humberi IP 46 and hydrogel yield extended control. • Findings in field tests strengthen benefit of the device for focal application.

Optimization of granular formulations of Metarhizium humberi microsclerotia with humectants

Abstract: Granular microsclerotial formulations of entomopathogenic fungi deserve attention because of their post-application, in situ production of new conidia that enhance and prolong mycoinsecticidal efficacy against a target pest insect. Because high ambient moisture is a crucial condition to induce fungal development and conidiogenesis on granules, we tested the impacts of the additions of three humectants-glycerin, propylene glycol, and polyethylene glycol 400-on water absorption by pellets incorporating microsclerotia of Metarhizium humberi IP 46 with microcrystalline cellulose or vermiculite carriers, and on the production of infective conidia of IP 46 microsclerotia in ambient humidities suboptimal for routine conidiogenesis. Glycerin facilitated greater and faster absorption of water than the other humectants. Microcrystalline cellulose absorbed low quantities of water without any added humectant whereas vermiculite did not. IP 46 did not grow or sporulate on pellets prepared with or without glycerin at 86% relative humidity (RH) or on control pellets without glycerin at 91% RH; conidial production on pellets prepared with vermiculite or microcrystalline cellulose and 10% glycerin reached 1.1 × 105 conidia/mg and 1 × 105 conidia/mg, respectively, after 20 days of exposure at 91% RH. Hence, these results strongly support glycerin as a suitable humectant for granular microsclerotial formulations of this fungus.