Some genetic aspects of the resistance of Spodoptera frugiperda to a nuclear polyhedrosis virus

A probit analysis of the dosage-response of two isolates of Spodoptera frugiperda to a single nuclear polyhedrosis virus revealed a greater than 5-fold difference in the LD₅₀. The response of F₁ progeny of reciprocal crosses between the two parental isolates demonstrated that resistance to the virus is not sex-linked. The LD₅₀ values of F₁ and F₂ backcrosses suggest that the major variation in resistance is due to a single gene or genes that lack dominance.