1. Most of what is known about parasitoid behaviour comes from laboratory observations: field quantitative observations on searching parasitoids are extremely difficult to do and are rare. The basic components of Aphytis melinus’s response to California red scale (Aonidiella aurantii) were studied in the laboratory: encounter, rejection, drumming, probing, oviposition, and hostfeeding. It was t...

Between 1990 and 1995, the USDA/APHIS National Biological Control Laboratory in Niles, MI, Texas A&M University, and the University of Massachusetts conducted a biological control introduction program against the Asian diaspidid scale insect Unaspis euonymi (Comstock), a pest of woody landscape plants. Two species of predators ( Chilocorus kuwanae Silvestri, Coleop.: Coccinellidae and Cybocepha...

We elucidate the mechanisms causing stability and severe resource suppression in a consumer-resource system. The consumer, the parasitoid Aphytis, rapidly controlled an experimentally induced outbreak of the resource, California red scale, an agricultural pest, and imposed a low, stable pest equilibrium. The results are well predicted by a mechanistic, independently parameterized model. The key...

The experiment was done in a lemon grove on the high school farm in Fillmore, Ventura County, California. The grove is managed using IPM methods and is under successful biological control for California red scale. Lorzban is sprayed annually on the ground for ant control but the area we sampled was not sprayed during our experiment. No other pesticides or oil treatments are used. Aphytis melinu...

The efficacy of natural enemies in controlling pests under field conditions is largely correlated with their capacity to spread within infested crops. In this study the spatial dispersal of the California red scale parasitoid Aphytis melinus DeBach (Hymenoptera: Aphelinidae) was evaluated in the field after augmentative releases. The experiment was conducted in 2007 in six 1-ha plots in a Sicil...

We used field observations of freely foraging Aphytis aonidiae parasitoids in conjunction with results of laboratory studies of A. aonidiae and other Aphytis species to simulate lifetime patterns of behavior and reproduction. Field observations provided estimates of encounter rates with three classes of hosts, the mortality rate from predation on adult parasitoids, and host-handling times for o...