Interactions Between Woolly Whiteflies and Their Parasitoid Wasp: Development, Competition, and Reproductive Potential

Abstract

Whiteflies are important pests that severely impact crop yield through feeding and as vectors of pathogens. We focus on the woolly whitefly, Aleurothrixus floccosus, and its parasitoid wasp, Cales noacki, used for biological control. This research is motivated by the challenges of managing whitefly populations, intensified by the limitations of pesticides and the increasing prevalence of whitefly infestations in new regions worldwide. Our findings reveal that parasitism by Cales noacki prolongs the development time of woolly whiteflies when the whitefly eventually overcomes the parasitoid. Wasps emerging from the fourth instar of the whitefly nymphs were larger and had higher reproductive potential than those emerging from earlier instars. We found a positive correlation between wasp size and the number of eggs in the ovary for wasps emerging from the third instar of the whitefly nymphs. However, no such correlation was found for wasps emerging from the fourth instar. Additionally, competition between whiteflies and other common pests, such as citrus mealybugs and citrus mites, seemed to hinder the emergence success of whiteflies, suggesting that multi-pest interactions could affect biological control strategies. These results demonstrate the complex life-history interactions between woolly whiteflies and their parasitoid wasps, pointing to the importance of integrating ecological considerations into pest management practices. Understanding these dynamics is important for developing effective control methods, especially in the face of global climate change, which might further reduce the efficiency of parasitoid wasps.