Published research factors influencing the use of pesticides are discussed. One section reviews recent research on the effects of new pesticides that include insect growth regulators, including Permethrin(R), Altosid(R), and Dimilin(R). In life-cycle toxicity tests with the mysid Mysidopsis bahia, the 96-hr LC50 of Dimilin was 2.06 micrograms/l (95%) CL= 1.63 to 2.69 micrograms/l and estimated concentration of 75 micrograms/l (parts per trillion) significantly reduced the number of young produced by each female mysid. Author concludes: (1) more emphasis is needed on predicting or monitoring obvious potential sources of accidental estuarine contamination, as is being made possible by recent toxic substances legislation; (2) the ecological importance of non-point source of pesticides is documented from reports of effects observed on field populations of non-target animals exposed to a number of pesticides; (3) laboratory studies may underestimate the potential for environmental damage in the field.