Isolation, identification and virulence of indigenous entomopathogenic fungal strains against the peach-potato aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), and the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Egyptian Journal of Biological Pest Control

Table 5 Median lethal time (LT₅₀) values for the indigenous strains of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae bioassayed against 3rd instar larvae of fall armyworm Spodoptera frugiperda under laboratory conditions

EPF strains	Concentrations (conidia/ml)	LT₅₀ (days)	Lower and upper 95% Fiducial limits (days)	X² (df = 30)*	P-value	Slope ± SE
Beauveria bassiana	1.0 × 10⁹	7.750	7.142 – 8.540	111.67	≥ 0.001	5.056 ± 0.224
Beauveria bassiana	1.0 × 10⁸	8.705	7.919 – 9.905	95.075	≥ 0.001	4.721 ± 0.245
Metarhizium anisopliae	1.0 × 10⁹	7.027	6.426 – 7.619	164.64	≥ 0.001	5.589 ± 0.225
Metarhizium anisopliae	1.0 × 10⁸	7.931	7.245 – 8.902	107.81	≥ 0.001	4.890 ± 0.232

*Since the significance level is less than 0.150, a heterogeneity factor is used in the calculation of confidence limits