A Membrane Filter Bioassay for Studying Phagostimulatory Materials in Leaf Extracts1

Gustatory responses of a specialist and a generalist grasshopper to terpenoids of Artemisia ludoviciana

“…Gustatory bioassays were conducted using nitrocellulose membrane discs (Schleicher & Schuell, 2.5 cm diameter) (Bristow et al, 1979). Adults of two species of grasshoppers were used in this investigation.…”

Assays for Insect Feeding

“…Filter paper has been used in the past (e.g., Marek, 1961 for testing aphid probing responses to various chemicals), but Millipore filters (Bristow et al, 1979) and glass fiber discs (Whatman GF/A) (Stadler and Hansen, 1976;Adams and Bernays, 1978) are chemically pure, absorbent, and readily eaten by many insects when phagostimulant is added (Fig. 1).…”

“…This method requires a constant relationship between dry and fresh weight and that the insect feed completely through the substrate. For small insects photographic enlargements of the substrate can be measured in the above ways (Bristow et al, 1979). Visual estimate of area loss is best used only when frequently confirmed with an independent, though more time-consuming, measure (Jones et al, 1981).…”

Bioassay Methods with Terrestrial Invertebrates

“…Filter paper has been used in the past (e.g., Dethier 1941), but cellulose acetate filters (Bristow et al 1979;Navon et al 1993) and disks made from thin glass fibers (SHidler & Hanson 1976; Adams & Bernays 1978) also have been used for their ease of chewing compared to filter paper, in addition to their chemical purity, absorbency, and uniformity.…”

“…Implicit in the process of estimating consumption from area are (1) that the test chemical was evenly applied to the substrate and (2) for leaf disks, that there is a constant relationship between dry and fresh weight and that the insects feed completely through the disk. For small insects photographic enlargements of the substrate prior to measurement may be necessary (Bristow et al 1979), although this increases the expense.…”