Effects of adult western corn rootworm, Diabrotica virgifera virgifera LeConte, feeding on corn yield were assessed over a 4-year period by confining beetles in various densities to corn ears. Corn rootworm survival was good under conditions of the study and generally resulted in a direct positive correlation between beetle number and superficial injury. However, analysis of yield parameters (kernel weight, and kernel number per ear quarter and per ear) indicated that densities of up to 20 beetles per ear did not significantly reduce yield. Some evidence of compensation was observed, with the tip quarter of the ear often exhibiting a positive linear response to beetle density, and the other ear quarters exhibiting nonlinear responses. Similarly, mechanical defoliation studies suggested that moderate levels of silk clipping could be tolerated.
No takes yet. Share an insight, caveat, or question.
Capinera et al. (1986) studied this question.