Evaluating the virulence of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) and Beauveria bassiana (Ascomycota: Hypocreales) isolates to Arabian rhinoceros beetle, Oryctes agamemnon arabicus

Abstract

Virulence of entomopathogenic fungi <em>Metarhizium anisopliae</em> and <em>Beauveria bassiana</em> were tested against Arabian Rhinoceros Beetle, <em>Oryctes agamemnon arabicus</em> larvae. Four concentrations (1×10<sup>5</sup>, 1×10<sup>7</sup>, 1×10<sup>9</sup> and 1×10<sup>11</sup> conidia/mL<sup>–1</sup>) of two locally isolated entomopathogenic fungi spore suspensions were used in this study via larval direct spraying. Results revealed that both isolates can cause high mortality rate reaching 100% after 29 days. However, <em>Beauveria bassiana</em> scored higher mortality rate in short time especially at the concentration of 1×10<sup>11</sup> conidia/ mL<sup>–1</sup> with lethal time (LT)<sub>50</sub> 12.75 and LT<sub>90</sub> 20.00; while, <em>Metarhizium anisopliae</em> caused the higher percentage of malformed adults. Moreover, both isolates affected insect’s life cycle particularly in the pupal stage which was reduced remarkably by almost 50% in comparison with the control treatment.

Assessment of the virulence and proteolytic activity of three native entomopathogenic fungi against the larvae of Oryctes agamemnon (Burmeister) (Coleoptera: Scarabaeidae)

“…It was not calculated at the concentration of 10 8 . In a similar study, Khudhair et al (2015) reported that the LT 50 value for O. agamemnon arabicus larvae treated with B. bassiana was 12.75 days. Latifian and Rad (2012) found that the LT 50 in adults of O. elegans ranged 7.21-11.62 days for B. bassiana, 6.45-10.12 days for B. brongniartii, and 6.05-10.89 days for M. anisopliae.…”

Bioefficacy of different formulations of Metarhizium anisopliae (Metchnikoff) Sorokin IOF strain (KF408075) against Oryctus rhinoceros (Linnaeus) in vitro condition

“…The variation in virulence of different isolates, origin from different geographical locations were reported by various workers (Fernando et al, 1995) [2] reported that the M. anisopliae caused 100% mortality of Oryctes rhinoceros larvae and adults when treated with suspensions of 10 7 cfu / ml, in laboratory condition. (Khudhair et al, 2015) [5] reported that, the virulence of entomopathogenic fungi Metarhizium anisopliae was tested against Arabian Rhinoceros Beetle, Oryctes agamemnon arabicus (Illiger) larvae at (1×10 9 cfu /ml) locally isolated entomopathogenic fungi spore suspensions directly sprayed on grubs to cause high mortality rate reaching 100% after 29 days. Makaka and Caston (2008) [7] reported that, oil based formulation of M. anisopliae isolate (IMI098376) found least LC50 value (4.47x10 4 cfu / ml) against black maize beetle, Heteronychus licas (Seidlitz) at 13.30 weeks.…”

Virulence of Metarhizium rileyi Is Determined by Its Growth and Antioxidant Stress and the Protective and Detoxifying Enzymes of Spodoptera frugiperda

“…Spore suspensions with a concentration of 1.0 × 10 7 conidia/mL were prepared, and 1 µL of conidia from the XSBN200920 or HNQLZ200714 strains was inoculated to the center of SDAY and PDA medium by the spot joint method, respectively, and incubated in a light incubator at 25 °C for 7 days at 16 h light/8 h dark photoperiod. Colony color, morphology, texture, and edge shape were photographed, and colony diameter was measured [ 21 ]. Conidia of XSBN200920 and HNQLZ200714 strains were diluted to 1.0 × 10 6 conidia/mL.…”