Effects of water extracts of leaves of various plants and desert locust frass after locusts fed on these plants on the numbers of egg pods laid when extracts were mixed with sand and presented to adult female desert locusts. Two cups containing leaf and frass extracts were simultaneously presented to locusts in each of two locust cages for three to five days, and the data were combined. Numbers in parentheses indicate the total numbers of days observed. Bars on histograms indicate one standard deviation. Asterisks indicate significant differences at the 5% level with a t-test. n.s. indicates no significant difference. DG, Dactylis glomerata (orchard grass); BO, Brassica oleracea var. capitata (cabbage); SB, Sorghum bicolor (sorghum); LS, Lactuca sativa var. longifolia (romaine lettuce); BR, Brassica rapa var. perviridis (Japanese mustard spinach); MS, Miscanthus sinensis (silver grass).