Native Resistance to Western Corn Rootworm (Coleoptera: Chrysomelidae) Larval Feeding: Characterization and Mechanisms

Abstract

Seven maize, Zea mays L., genotypes selected for native resistance to western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), larval feeding damage (SUM2068, SUM2162, CRW3(S1)C6, NSS1 x CRW3(S1)C6, PI583927, CRW2(C5), and AR17056-16) were evaluated along with three control maize genotypes in the field for plant damage, larval recovery, adult emergence, root size, and root regrowth. Larvae recovered were further analyzed for head capsule width and dry weight and adults for dry weight. All factors evaluated with the exception of adult dry weight varied significantly among maize genotypes. Control genotypes included a highly susceptible hybrid, B37 x H84, a transgenic rootworm-resistant hybrid expressing the modified Cry3A protein (MIR604), and the untransformed modern hybrid with the same genetic background as the MIR604 we used (isoline) as a second susceptible control. In general, the genotypes previously selected for resistance to western corn rootworm larval feeding had less damage, fewer larvae recovered, smaller larvae recovered, and fewer adults recovered than the susceptible controls. SUM2162 was significantly less damaged than all other native sources of resistance. Western corn rootworm larvae recovered from SUM2162 and SUM2068 were significantly smaller in terms of head capsule width and average weight than larvae recovered from all other maize genotypes, indicating that antibiosis is a mechanism of resistance for these two hybrids.

Effect of MIR604 Transgenic Maize at Different Stages of Development on Western Corn Rootworm (Coleoptera: Chrysomelidae) in a Central Missouri Field Environment

“…Although the mortality of western corn rootworm larvae because of feeding on MON863 was equivalent across maize developmental stages, growth of surviving larvae appeared relatively normal. Data from our study show a similar trend and are consistent on this point with data from Al-Deeb and Wilde ( ), Storer et al (2006, Oyediran et al (2007), andEl Khishen et al (2009). There were generally no signiÞcant differences between the size of insects (i.e., dry weight and head capsule width) recovered from MIR604 and isoline maize.…”

Isolation and Characterization of Host Recognition Cues in Corn Roots for Larvae of the Western Corn Rootworm (Coleoptera: Chrysomelidae)

“…We previously tested larval host recognition responses to seven corn genotypes (Bernklau et al 2010) that were selected for native resistance (El Khishen et al 2009). In Þeld tests, these varieties had less feeding damage than susceptible control plants, and fewer and smaller larvae and fewer adults were recovered from these genotypes compared with the controls (El Khishen et al 2009).…”

“…We previously tested larval host recognition responses to seven corn genotypes (Bernklau et al 2010) that were selected for native resistance (El Khishen et al 2009). In Þeld tests, these varieties had less feeding damage than susceptible control plants, and fewer and smaller larvae and fewer adults were recovered from these genotypes compared with the controls (El Khishen et al 2009). Despite their superior performance in the Þeld, behavioral bioassays showed no signiÞcant differences in larval host recognition responses between susceptible corn and any of the resistant varieties (Bernklau et al 2010).…”

Antixenosis in Maize Reduces Feeding by Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae)

“…B37ϫH84 is a particularly susceptible maize genotype that has been used as a susceptible control in both Þeld and laboratory studies (Hibbard et al 1999bPrischmann et al 2007Prischmann et al , 2009aEl Khishen et al 2009). In the current study fewer larvae fed and stayed on this line than on most of the other genotypes ( Fig.…”