Field testing rubidium marking for quantifying intercrop movement of predatory arthropods Academic Article uri icon


  • Applications of two doses of an internal physiological marker, rubidium, were applied as foliar solutions of rubidium chloride (RbCl) to field plots of cotton, Gossypium hirsutum L., and grain sorghum, Sorghum bicolor (L) Moench, to determine the potential of this technique for detecting intercrop movement of generalist predators. Because artificially elevated rubidium levels of marked plants and insects decline with time, three applications were made at distinct phenological stages of grain sorghum to test if multiple mark-recapture experiments could be conducted at the same sites. Samples of predators and plant tissues were made at the onset of each sampling period and every 2 d through 6 d after RbCl application. Results showed that both crops, as well as all arthropod predators tested, exhibited significant elevation of rubidium levels over field-collected controls. Further, the effectiveness of the mark did not differ between crops, indicating that one set of protocols is sufficient for marking in both crops. No differences in mark effectiveness were detected between doses until the last sampling period, 6 d after mark application, and then only in one of three taxa. Using this method, we detected predator movement between crops, and the percentage of positive recaptures (>6%) was higher than those in similar studies using different marking systems. These results collectively suggest that this method can be used to elucidate the relationship between predator populations in these crops, and that it is potentially applicable to other multiple-crop agroecosystems.

published proceedings


author list (cited authors)

  • Prasifka, J. R., Heinz, K. M., & Sansone, C. G.

citation count

  • 19

complete list of authors

  • Prasifka, JR||Heinz, KM||Sansone, CG

publication date

  • August 2001