Predatory activity of Butlerius nematodes and nematophagous fungi against Haemonchus contortus infective larvae.

The purpose of this study was to evaluate the predatory activity of the nematode Butlerius spp. and fungal isolates of Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis and Trichoderma esau against H. contortus infective larvae (L3) in grass pots. Forty-eight plastic gardening pots containing 140 g of sterile soil were used. Panicum spp. grass seeds (200 mg) were sown into each pot and individually watered with 10 mL of tap water. Twelve days after seeding, the pots were randomly divided into 6 groups (n=8). Two thousand H. contortus infective larvae (L3) were added to each group. Additionally, the following treatments were established: Group 1 - 2000 Butlerius spp. larvae; group 2 - A. musiformis (1x107 conidia); group 3 - T. esau (1x107 conidia); group 4 - C. rosea (1x107 conidia), group 5 - D. flagrans (1x107conidia) and Group 6 - no biological controller (control group). The larval population of H. contortus exposed to Butlerius spp. was reduced by 61.9%. Population reductions of 90.4, 66.7, 61.9 and 85.7% were recorded in the pots containing A. musiformis, T. esau, C. rosea and D. flagrans, respectively. The results of this study indicate that the predatory nematode Butlerius spp. and the assessed fungi display an important predatory activity can be considered suitable potential biological control agents.

Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae.

The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 10(6). Group 4 received the combination of 5 × 10(6) D. flagrans chlamydospores + 5 × 10(6) C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species.

Fungal Antagonism Assessment of Predatory Species and Producers Metabolites and Their Effectiveness on Haemonchus contortus Infective Larvae.

The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness on Haemonchus contortus infective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the species Duddingtonia flagrans, Clonostachys rosea, Trichoderma esau, and Arthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3 of H. contortus. D. flagrans (Assay A) produced 5.3 × 10(6) spores and associated with T. esau, A. musiformis, or C. rosea reduced its production by 60.37, 45.28, and 49.05%, respectively. T. esau produced 7.9 × 10(7) conidia and associated with D. flagrans, A. musiformis, or C. rosea reduced its production by 39.24, 82.27, and 96.96%, respectively. A. musiformis produced 7.3 × 10(9) spores and associated with D. flagrans, T. esau, or C. rosea reduced its production by 99.98, 99.99, and 99.98%, respectively. C. rosea produced 7.3 × 10(8) conidia and associated with D. flagrans, T. esau, or A. musiformis reduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi.

Predatory activity of Butlerius nematodes and nematophagous fungi against Haemonchus contortus infective larvae / Atividade predatória de nematóides Butlerius e fungos nematófagos contra larvas infectantes de Haemonchus contortus

Abstract The purpose of this study was to evaluate the predatory activity of the nematode Butlerius spp. and fungal isolates of Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis and Trichoderma esau against H. contortus infective larvae (L3) in grass pots. Forty-eight plastic gardening pots containing 140 g of sterile soil were used. Panicum spp. grass seeds (200 mg) were sown into each pot and individually watered with 10 mL of tap water. Twelve days after seeding, the pots were randomly divided into 6 groups (n=8). Two thousand H. contortus infective larvae (L3) were added to each group. Additionally, the following treatments were established: Group 1 – 2000 Butlerius spp. larvae; group 2 – A. musiformis (1x107 conidia); group 3 – T. esau (1x107 conidia); group 4 – C. rosea (1x107 conidia), group 5 – D. flagrans (1x107conidia) and Group 6 – no biological controller (control group). The larval population of H. contortus exposed to Butlerius spp. was reduced by 61.9%. Population reductions of 90.4, 66.7, 61.9 and 85.7% were recorded in the pots containing A. musiformis, T. esau, C. rosea and D. flagrans, respectively. The results of this study indicate that the predatory nematode Butlerius spp. and the assessed fungi display an important predatory activity can be considered suitable potential biological control agents.

Resumo O objetivo deste estudo foi avaliar a atividade predatória do nematoide Butlerius spp. e isolados fúngicos de Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis e Trichoderma esau contra larvas infectantes (L3) de Haemonchus contortus em vasos plantados com Panicum spp. Foram utilizados quarenta e oito potes plásticos de jardinagem contendo 140 g de solo estéril, 200 mg de sementes de Panicum spp.. Cultivar colonião, foi semeado em cada vaso e, diariamente, molhados com 10 mL de água da torneira. Doze dias após, os vasos foram divididos em 6 grupos (n = 8), e duas mil L3 de H. contortus foram adicionadas a cada vaso. Foram estabelecidos os seguintes tratamentos: Grupo 1 - 2.000 larvas de Butlerius spp.; Grupo 2 - A. musiformis (1x107 conídios); grupo 3 - T. esau (1x107 conídios); grupo 4 - C. rosea (1x107 conídios); grupo 5 - D. flagrans (1x107conidia); e Grupo 6 – somente L3 de H. contortus que serviu como controle negativo. A população de L3 de H. contortus expostas a Butlerius spp. foi reduzida em 61,9%. Redução populacional de 90,4, 66,7, 61,9 e 85,7% foram observadas nos vasos contendo A. musiformis, T. esau, C. rosea e D. flagrans, respectivamente. Os resultados deste estudo indicaram que o nematoide Butlerius spp. e os fungos avaliados exibiram importante atividade predatória e podem ser considerados como agentes de controle biológico.