Ant Nest Soil Research Articles

Growth of Beauveria bassiana in Fire Ant Nest Soil with Amendments

Studies evaluated the capacity of Beauveria bassiana (Bals.) Vuill. to grow, spread, and sporulate in soil from fire ant ( Solenopsis invicta Buren) nests, with or without nutrient amendments. Amendments included fire ant carcasses, chitin, and rice. Soil obtained from fire ant nests was inoculated with B. bassiana as mycelial mats, conidial suspension, or infected cadavers. No significant differences in colony diameters were detected among the nonsterile soil treatments regardless of inoculum type, but in sterile soil amended with ants or rice, fungal colonies were significantly larger than colonies on control or chitin-amended soil. CFU counts also showed similar results. Ground rice and either sodium dodecyl sulfate-clean or natural ant carcasses showed equally beneficial effects on fungal growth in sterile soil. Results suggest that addition of tested amendments to the nest soil, as would be accomplished by formulation of microbial insecticides, may not offer any advantage to the development of epizootics of B. bassiana in fire ant nests.

Ant-nest soil and seedling growth in a neotropical ant-dispersed herb.

A major hypothesis concerning the benefits of myrmecochory, seed dispersal by ants, to plants is that ant nests are nutrient-enriched microsites that are beneficial to seedling growth. We experimentally test this hypothesis for a neotropical myrmecochore, Calathea ovandensis, asking two questions: 1) is soil of nests of a seed-dispersing ant chemically or structurally distinct from surrounding soils, and 2) do seedlings grow better in soil collected from ant nests than in randomly collected soil? We found that although ant-nest soil was significantly enriched in nitrate-nitrogen, magnesium, iron, manganese, cadmium and percent organic matter compared to randomly collected soil, seedling growth was not significantly improved by ant-nest soil.