Effect of Zelus longipes againts Diaphorina citri and its parasitoid Tamarixia radiata under controlled conditions

The Asian Citrus Psyllid  Diaphorina citri is an invasive pest that represents a major threat for the american citrus industry.  Nymphs and adults extract the sap of citrus leaves and excrete honeydew, but more importantly, D. citri transmits  the most devastating diseases of citrus trees in the world, the “greening” or “huanglongbing”. One of the more abundant natural enemies of D. citri in South Florida is the reduviid Zelus longipes. This  study focused on the effect of this predator on the populations of D. citri and its parasitoid T. radiata under controlled conditions. Different densities of adults and 1st instar nymphs of Z. longipes were placed in experimental arenas with fixed numbers of D. citri nymphs, adults and T. radiata adults. Adults and nymphs of Z. longipes preyed on adults of D. citri and T. radiata. They also preyed on nymphs of D. citri but at a lower rate. Female Z. longipes adults preying on D. citri showed a Type III functional response. An experiment addressing prey preference showed that 1st instar nymphs of Z. longipes preferred to prey upon T. radiata adults over D. citri adults, while female Z. longipes preferred to prey upon Anastrepha suspensa adults over D. citri adults. With these antecedents, field experiments are needed to find if intraguild predation occurs outdoors and how this relates to reduce the effectiveness of parasitoids.