With the advancement in production of monoclonal antibodies (MAbs) that are species specific the use of serological assay as a tool for assessing natural enemies has increased during the last decade (Greenstone 1996). Serological assay has been used widely overseas to estimate the potential of predators as biological control agents. It offers advantages over other predator assessment trials in that it provides a method of quickly screening a complex of predators and can be utilised to determine the stage of prey being consumed as well as the species of prey consumed. Furthermore, it offers a means of establishing when (at what time of year) predators are feeding on target prey. If high numbers of predators are found to consume target prey at certain times of a growing season the need for chemical control may be reduced at those times. This may aid in resistance management strategies.