Evaluation of fungal pathogens, Fusarium semitectum Berk. and Ravenel and Hirsutella thompsonii Fisher against red spider mite, Tetranychus neocaledoni-cus (Andre) of okra under laboratory and greenhouse conditions

Abstract

Efficacy of fungal pathogens, Fusarium semitectum Berk. and Ravenel and Hirsutella thompsonii Fisher was evaluated against red spider mite, Tetranychus neocaledonicus (Andre) of okra under laboratory and greenhouse conditions. Among the treatments evaluated under laboratory conditions, the highest mortality of 78.20 and 88.34 percent adults and immatures, respectively was recorded at 2.10 x 109 spores per ml of F. semitectum, whereas it was 82.05 and 92.31 per cent adults and immatures, respectively in case of H. thompsonii at 4.60 x 108 spores per ml. Among the twelve treatments evaluated under greenhouse conditions, H. thompsonii 4.60 x 108 spores per ml, F. semitectum 2.10 x 109 spores per ml + H. thompsonii 4.60 x 108 spores per ml, H. thompsonii 4.60 x 108 spores per ml + dicofol 0.025% and F. semitectum 2.10 x 109 spores per ml + H. thompsonii 4.60 x 108 spores per ml + dicofol 0.025% were found to be on par with each other with a cumulative percent mortality of 81.20, 81.48, 81.21 and 82.59 percent, respectively. By testing the field efficacy of F. semitectum and H. thompsonii against T. neocaledonicus, these fungal pathogens can be used as potential biocontrol agents for the sustainable management of mites on okra. Hence the present study evaluates the potentiality of F. semitectum for the management of T. neocaledonicus by comparing with the well-known acaricidal fungus, H. thompsonii.

Assessment of Entomopathogenic Fungi for the Biocontrol of Sucking Insect Pests: Pertaining to Red Spider Mites (Tetranychus urticae)

“…The results showed that all stages were susceptible to both H. thompsonii was more effective against eggs at its LC 50 value. Similar results were obtained by Fiedler et al [27], Tamai et al [25], and Rachana et al [24] during their studies on mites [28].…”

“…The host preference of the isolates might vary based on the species, or it could be attributed to differences in the production of extracellular enzymes [21,23]. Rachana et al [24] reported that the treatment with H. thompsonii at 4.6x10 2). The results of lethal time (50 and 90 percent mortality) showed that the LT 50 and LT 90 values for Isaria isolate were higher (6.19 days and 11.03 days, respectively) compared with Hirsutella isolate (5.99 days and 11.12 days, respectively) (Table 3).…”

Identification of locally isolated entomopathogenic Fusarium species from the soil of Changa Manga Forest, Pakistan and evaluation of their larvicidal efficacy against Aedes aegypti

“…as efficient entomopathogen against many insects including Culex quinquefsciatus, Anopheles stephensi, Sitophilus oryzae, Tetranychus neocaledonicus, Tropidacris collaris, Lymantria obfuscate, Tetranychus urticae etc. (Munshi et al, 2008;Mohanty et al, 2008;Rachana et al, 2009;Pelizza et al, 2011;Batta, 2012;Tangtrakulwanich et al, 2014;Vivekanandhan et al, 2018;Wu et al, 2018). Santos et al (2020) published a review study based on a survey of peer-reviewed papers published from 2000 to 2019, presenting the significant pathogenicity of Fusarium spp.…”