Resistance‐Susceptibility of Maize Genotypes to Artificial Infestations by Twospotted Spider Mites

Abstract

Twospotted spider mites, Tetranychus urticae K., are pests of maize, Zea mays L., in some areas of the USA. Resistant genotypes are needed to reduce plant damage caused by this pest. Two laboratory and three field experiments were conducted in 1986 to determine the resistance‐susceptibility of maize genotypes to an artificial infestation by the twospotted spider mite. Inbred line 41:25046 was highly resistant to the twospotted spider mite in both laboratory and field tests. This inbred exhibited a high degree of antibiosis against the mite; few mites survived, and little leaf damage resulted from the artificial infestation. This inbred also is highly resistant to the European corn borer, Ostrinia nubilalis Hiibner, and has been used as a nonrecurrent parent to develop several genotypes of maize resistant to this pest. Our data show that 41:25048 also could be used to develop genotypes of maize resistant to twospotted spider mites. Nine other genotypes had intermediate or susceptible reactions to twospotted spider mites, with Mol7 being the most susceptible.

Genotypic response of brachiaria (Urochloa spp.) to spider mite (Oligonychus trichardti) (Acari: Tetranychidae) and adaptability to different environments

“…Similarly, a variety of zoysia grass (Zoysia tenuifolia) with high level of resistance to bank grass mite Oligonychus pratensis (Banks) (Acari: Tetranychidae) was identified by Busey et al (1982). Host plant resistance to mites have also been identified in maize (Bynum et al, 2004;Kamali et al, 1989).…”

Fitness ofTetranychus urticaeKoch (Acari: Tetranychidae) on different soybean cultivars: biology and fertility life-tables

“…Patterson et al, 1974;Shanks and Barrit, 1975;Kamali et al, 1989). In these studies, mortality of the individual mites was considered as the main endpoint for host plant resistance examinations.…”

Maize inbred line B96 is the source of large-effect loci for resistance to generalist but not specialist spider mites

“…The inability to effectively control spider mites with pesticides, coupled with their importance as pests during hot and dry conditions, has generated interest in understanding the extent and magnitude of spider mite resistance in maize germplasm, and variation in resistance has been observed for both T. urticae and O. pratensis in multiple studies (Owens et al 1976; Archer 1987; Kamali et al 1989; Mansour, F. and Bar-Zur, A. 1992; Mansour et al 1993; Tadmor et al 1999; Bynum et al 2004a, b).…”