''Resistance management'' tactics have been much discussed, but such t
actics have provided surprisingly limited practical results for pest m
anagement programs to date. We have learned a great deal about pestici
de resistance mechanisms, the mode of inheritance of resistances, the
molecular basis of resistance and cross resistance mechanisms, and how
to evaluate the impact of resistance on fitness. However, it remains
difficult to ''manage'' resistance once resistant individuals make up
more than 5 to 10% of the population. Generally, the best that can be
achieved is to delay the development of high levels of resistance for
a few years, most often by using the product less often. A more effect
ive resistance management strategy will combine a variety of effective
pest management tactics along with a reduction in numbers and rates o
f pesticides applied. Effective pest management tactics include monito
ring, evaluating economic injury levels so that pesticides are applied
only when needed, biological control, host plant resistance, cultural
controls, biorational pest controls, and genetic control methods. As
a part of this multi-tactic strategy, it is crucial to evaluate the im
pact of pesticides on natural enemies. Sometimes, pesticide-resistant
natural enemies can be effective components of a program to delay the
development of resistance in pest arthropods.