The southern corn rootworm (Diabrotica undecimpunctata howardi Barber) is the primary soil insect pest of peanut (Arachis hypogaea L.) in Virginia and North Carolina. The majority of acreage is planted to recently released cultivars which have not been extensively screened for rootworm resistance. The objectives of this study were to evaluate five virginia-type cultivars (NC-V 11, VA-C 92R, VA 93B, NC 10C, and AgraTech VC-1) and 19 breeding lines for resistance to southern corn rootworm and develop efficient resistance laboratory and field screening techniques for peanut. Laboratory-grown seedlings and pegs, and immature and mature pods taken from field-grown plants were used in bioassays. Neonates from a laboratory colony were reared to the adult stage on plant tissues and evaluated for mortality. Pod damage was determined from field studies where plants were exposed to natural southern corn rootworm infestations. With seedling feeding, NC 6 resulted in significantly more rootworm mortality as compared to NC 7, NC 9, NC 10C, NC-V11, N90013E, PI 121067, AgraTech VC-1, VA 93B, VA 861101, and VA 9211290. With feeding on field-grown peg and immature pod tissues, NC 6 also resulted in significantly more rootworm mortality compared with NC 7, AgraTech VC-1, VA 93B, and VA 861101. In field studies, NC 6 also incurred significantly less total pod damage than NC 7. Results indicate that NC 6 is still the only cultivar currently planted that demonstrates significant resistance to southern corn rootworm.

This content is only available as a PDF.

Author notes

1 Res. Assoc. and Ext. Entomologist., Dept. of Entomology, Virginia Polytech. Inst. and State Univ., 6321 Holland Rd, Suffolk, VA 23437 and Res. Genet., U. S. Water Conservation Lab, 4331 E. Broadway Rd., Phoenix, AZ 85040-8832.