Determining the impact of species considered potentially important natural enemies of crop pests is crucial for making robust management decisions as part of an IPM programme (Ives 1980; Johnson et al. 2000; Wilson 2002). Determination of prey species present in the diet of predaceous arthropods is an initial step in assessing their potential impact as biological control agents. Pacific damsel bugs are classified as 'generalist' predators, as they are known to feed on a large number of species from various taxonomic groups; 19 known arthropod species from 11 families in four orders are presently recognised as prey; including cotton aphids, Aphis gossypii, Glover, Heliothis, Helicoverpa armigera (Hubner), and mirids, Creontiades spp. Despite this, distinct biases are likely to exist for particular prey species. Measurement of the feeding rates of key predaceous arthropods on selected prey species, and elucidating the factors that affect this, is the next step in assessing their potential impact. Unfortunately laboratory tests tend to overestimate feeding rates by using artificially high prey densities; such results would not be applicable to field conditions without further testing. For example, the number of heIiothis eggs consumed by female Pacific damsel bugs, Nabis kinbergii Reuter, in 24 hours was reduced by 77, 74 and 92 % when caged on a single small, medium or large cotton plant, respectively, compared to a Petri dish (51.3 eggs per bug per day) (Johnson 1999). This suggests the ability of predators to find and consume prey is substantially reduced as the crop canopy expands and becomes more complex. A good approach to quantify the impact of predation by Pacific damsel bugs on arthropod pest densities is to combine a range of techniques, such as direct observation and cage inclusion studies. In this paper, we use glasshouse and field observations and glasshouse inclusion cage studies to determine the natural diet of the Pacific damsel bug, their feeding rates, and the influence of prey species, prey life stage and prey and predator density on these rates.