Abstract Interactions between the pea aphid, Acyrthosiphon pisum,and two of its natural enemies, the ladybird Coccinella septempunctataand the fungus Erynia neoaphidis,were examined in the laboratory. Adult C. septempunctatastarved for 48 or 24 hr or nonstarved were presented with aphid prey items at different stages of infection with E. neoaphidisand their feeding behaviors monitored. This demonstrated that, under laboratory conditions, C. septempunctataadults, particularly when starved for 48 hr, perceived A. pisuminfected with E. neoaphidisas acceptable food sources. This is a potentially antagonistic interaction as inoculum necessary for further transmission and the development of epizootics would be removed from aphid populations. However, less time was spent feeding, except by 48-hr-starved individuals, on infected than on uninfected aphids and the number of “feeding” versus “ignore” mouthpart encounters was greater for uninfected than infected aphids, thus limiting the severity of this antagonism. In addition, under laboratory conditions, C. septempunctataadults were able to passively vector infective conidia of E. neoaphidisto susceptible aphids and initiate infection in 10–11% of the population. Ladybird foraging on E. neoaphidis-infected aphids and their ability to vector infective conidia to susceptible aphid populations is discussed in relation to the epizootiology of the fungus and its implications for the manipulation of natural enemies in integrated management strategies.