| Abstract: | Seventy three species of seeds were presented to artificial colonies of Solenopsis invicta in the lab and the number of seeds removed and damage was recorded. Ants damaged and removed seeds most often when seeds were small and lightweight such as Eragrostis lehmanniana and Labiatae seeds. Seeds such as those produced by Glycine max, Vigna sinensis, and many other Leguminosae were too large and heavy to be removed or damaged by S. invicta. Seldom removed and damaged seeds that were not very large or heavy (Solanaceae and Sorghum halepense for example) probably had chemical defenses that discouraged ant predation. Tough seed coats of six species were scarified to determine whether seed coats protected endosperms and embryos from fire ant damage. When seed coats were scarified, ants consumed endosperms and embryos more often than when coats were left intact. Six seeds that were frequently removed and damaged by ants and five seeds that were not frequently removed and damaged were rinsed with hexane and acetone to determine if seeds had any chemicals that attracted or repelled ants. Sorghum halepense was the seed that was most affected. Rinsed S. halepense seeds were removed and damaged more often than unrinsed seeds indicating a repellent chemical may have been present. Extracts from seed rinsing were evaporated onto filter paper discs and compared to control discs to determine if there were any chemicals attractive or repellent to ants. Acetone rinse extracts from sesame and lettuce seeds were more attractive than controls indicating an attractive chemical. Six species of seeds were presented to S. invicta in a Held north of Bryan, Texas to determine if ants treated seeds in field situations as they did in the laboratory. Seeds were removed more often from bait stations in spring than in summer or fall. Fewer seeds were removed from bait stations that deterred ants, indicating ants had a significant effect on seed predation. Fewer seeds were removed from bait stations that deterred vertebrates, indicating vertebrates had a significant effect on seed predation. |
|---|