Grasshopper (Orthoptera: Acrididae) foraging on grasshopper feces: observational and rubidium-labeling studies.
Many grasshoppers are omnivores that feed on a variety of plants as well as on animal tissue and animal excrement. We conducted behavioral observations and rubidium chloride (RbCl) labeling studies to assess whether grasshoppers also feed on grasshopper feces, thus providing the potential for horizontal disease transmission. We observed 10 species of Acrididae feeding on grasshopper fecal pellets in 3 southwestern Montana rangeland communities during the summers of 1992 and 1994. Adults of both sexes and nymphs as young as 1st instars fed on the grasshopper feces soon after we placed the feces on the soil surface. The feeders included several species that are common pests: Aulocara elliotti Thomas, Ageneotettix deorum (Scudder), and Melanoplus sanguinipes (F.). Although activity tended to decline over the 2-h sampling period, grasshoppers continued to feed on feces even when high soil surface temperatures required them to undertake behaviors that alleviate thermal stress. There was also circumstantial evidence that grasshoppers completely consumed some of the 0.1-g samples within 24 h. We observed elevated levels of rubidium in the tissues of A. elliotti and M. sanguinipes after we gave them access to feces labeled with Rb in field cages. We discuss the implications of these findings for grasshopper biological control and diet studies.
Dec 1997. v. 26 (6)
|Main Author:||O'Neill, K.M.|
|Other Authors:||Woods, S.A., Streett, D.A.|
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