Efficacy of a mirid predator and an eulophid parasitoid to the tomato potato psyllid Bactericera cockerelli control on pepper plants

The tomato potato psyllid Bactericera cockerelli (Sulcer) (Hemiptera: Triozidae) is a serious pest of several solanaceous crops in different parts of the world. We examined the biological control potential of the zoophytophagous bug Engytatus varians (Distant) (Hemiptera: Miridae), in combination with the ectoparasitoid Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) on B. cockerelli-infested pepper (Capsicum annuum L.) plants in cages under greenhouse conditions. A single release rate (one adult per plant) of either E. varians or T. triozae was used and the timing of predator releases varied (before or after pest establishment). The number of nymphs and adults of B. cockerelli or the number of mirids (nymphs plus adults) and parasitoids (pupae plus adults) was determined three or four weeks after release. Both E. varians and T. triozae successfully established on pepper plants and significantly reduced the pest population density (by 91 to 96% and by 84 to 100% of nymphs and adults, respectively) when they were released separately or in combination, even when the predator was released before the establishment of B. cockerelli. At the end of the experiment, the density of E. varians was between one and two individuals per leaf, whereas that of the parasitoid was between one and six individuals per leaf in the treatments in which each natural enemy was released. These results could contribute to the integrated pest management of B. cockerelli. However, further studies are needed to validate the impact of both natural enemies on the control of this pest at a larger scale.