Comparative toxicities throughout the growing season for 24 new pesticides, including treatments applied on the soil surface, mixed into the upper 3 cm of soil and banded 3 cm below the surface, are presented graphically from data obtained in tests conducted during 1971, 1972 and 1973. When placed on the soil surface, most materials were initially highly toxic to test larvae and showed a continuous and relatively rapid loss of toxicity during the season. However, a few compounds, such as phosmet, phenamiphos and fonofos, appeared to be more resistant to photochemical degradation than others, such as phorate and propoxur. When mixed into the upper 3 cm of soil, toxicants of the most persistent compounds, as phoxim, fonofos, and pirimiphos-ethyl, degraded much faster than when the parent materials were banded 3 cm below the soil surface. However, there were only minor differences in rate of toxicant degradation of soil-mix and subsurface band treatments by some of the less residual compounds, as phenamiphos, propoxur and BAS2353 (3,5-diethyl-phenyl-N-methylcarbamate). Leptophos was the only compound tested that showed rapid initial loss of toxicity followed by an increase late in the season, both by the soil-mix and subsurface band methods of application. Efficient short or long term insect control must involve selection of the most suitable pesticide as its residual toxicity pattern relates to the life history and habits of the pest.