Q: Pesticide labels recommend several repeat treatments. Why not put on one good, thorough application and avoid the trouble of having to do it over? --V.K., Culver City
A: Many pests have complex life cycles that involve a variety of life stages and habits--adult, larval, migratory and so forth. Pesticides designed for insect control mainly target only immature "crawlers" and no other life forms. Repeated applications, in this case, control the successive hatches. Label directions should always be followed to the letter.