Soil adjacent to new brick veneer work is likely to have a higher pH owing to the mixture of cement with the soil. In the Gainesville, FL, area, soil samples taken from such locations had a range of pH values from 9.0 to 10.1; similar soils used in bioassays had a pH of 5.6 before the addition of cement. Addition of 15 mg of Portland cement to 33 g of soil increased the pH to 6, and addition of 291 mg of Portland cement increased the pH to 9. The pH of soil amended with cement was stable for the first 5 months. After 10 months, soil pH values decreased from alkaline to near neutral in all cases. Eastern subterranean termite workers, Reticulitermes flavipes (Kollar), were exposed to the treated soil at pH 6-9 for 24 h, and percentage mortality was recorded at 5 days, 5 months and 10 months. Termite mortality significantly decreased at higher soil pHs for bifenthrin, chlorpyrifos, fipronil and imidacloprid treatments at 5 months and similarly for bifenthrin, permethrin, chlorpyrifos, fipronil and imidacloprid treatments at 10 months. There was an inverse linear relationship between soil pH and mortality. Increased soil pH diminished residual activity of termiticide in the following order: imidacloprid > fipronil > chlorpyrifos = bifenthrin > permethrin > cypermethrin.

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Reliance on use of the Petri dish for bioassay studies has resulted in the majority of subterranean termite research being conducted in a manner that has not taken into account one of the most important feature of subterranean termites ecology: the soil in which they live. This artificial environment for bioassays, favored for its ease of use, may have resulted in accumulation of data about termite physiology, toxicology, pathology and behavior with limited biological relevancy. Caution should be taken when drawing conclusion from such experiments, because recent studies that made use of planar arenas (or 'two-dimensional arenas'), which provided soil-foraging conditions for termites and visibility for observation, have produced findings that are either contradictory to or more complete than corresponding Petri dish studies. The result of this study showed that groups of termites kept in planar arenas had better vigor and survivorship after 60 d than groups kept in Petri dishes. We also describe a list of technical advantages that the use of planar arenas can provide over the use of Petri dishes, and suggest that entomologists planning future laboratory studies on subterranean termites should consider using a similar protocol that involves planar arenas.