Eggs and small to medium-sized larvae of Spodoptera exigua (Huebner) (Lepidoptera: Noctuidae) are exploited by a complex of natural enemies in spring-planted sugarbeet fields in northern California. Field studies revealed that predation on sentinel egg masses ranged from [approximately]20 to 100%/egg mass; predation rate was lowest in fields previously treated with methomyl and highest in non-treated fields. Predators typically destroyed all of the eggs in a given egg mass; percentage predation per egg mass was density independent (spatial context). Survival of eggs (to neonate larvae) in cages that excluded predators ranged from [approximately]80 to [approximately]90%. The egg-predator guild consisted of adults and nymphs of Orius tristicolor (White) (Anthocoridae), Nabis americoferus Carayon (Nabidae), Lygus hesperus Knight (Miridae), and Geocoris punctipes (Say) (Geocoridae); larvae of Chrysoperla carnea (Stephens) (Chrysopidae); and adults of Collops vittatus (Say) (Melyridae). Laboratory evaluation revealed that large larvae of C. carnea and the adults of the other species (except for O. tristicolor) could consume 100 eggs of S. exigua in a 48 h period. The parasite guild associated with small and medium-sized larvae consisted of three species: Hyposoter exiguae (Viereck) and Pristomerus spinator (F.) (Ichneumonidae), both larval endoparasites; and Chelonus insularis Cresson (Braconidae), an egg-larval endoparasite. Parasitization in field samples ranged from [approximately]30 to [approximately]65%. Small and medium-sized larvae were also infected with a nuclear polyhedrosis virus (NPV); rates of NPV infection ranged from 0 to [approximately]35% in field samples. These results are consistent with anecdotal evidence that natural enemies, primarily generalist predators, are largely responsible for maintaining populations of S. exigua at relatively low levels in nontreated sugarbeet fields. Animals and man; Control; Biological control; Nutrition; Diet; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Habitat; Man made habitat; Land zones; Nearctic region; USA; North America Spodoptera exigua (Noctuidae); Biological control; Food plants; Sugar beet; Hymenopteran parasites; Parasite guild structure & biocontrol potential; Predators; Cultivated land habitat; California; Merced & Yolo counties; Natural enemy complex analysis & biocontrol potential, sugar beet fields Chelonus insularis (Braconidae ); Hyposoter exiguae; Pristomerus spinator (Ichneumonidae ); Control of; Spodoptera exigua (Lepidoptera); Lepidopteran hosts; Spodoptera exigua; Cultivated land habitat; California; Merced & Yolo counties; Biocontrol potential, sugar beet fields none