Cassava mealybug biological control delivers multi-faceted societal benefits

Abstract

As core component of sustainable intensification, biological control constitutes a tailor-made solution for the long-term management of both endemic and invasive pests. Here, drawing upon the example of the cassava mealybug ( Phenacoccus manihoti ; Hemiptera), we illuminate the myriad benefits of insect biological control. In 2008, the above mealybug invaded Asia, where it inflicted a 27% drop in aggregate cassava production and triggered a 260% surge in starch prices. Mealybug-induced shocks in Thailand's cassava output were offset by a 300,000-ha expansion of the agricultural frontier–accompanied with major loss of intact tropical forest. Mealybug outbreaks were permanently resolved through the release of the neotropical wasp Anagyrus lopezi (Hymenoptera). This minute parasitoid effectively suppressed P. manihoti at a continent-wide scale, restored food security, and delivered pest control services worth US$ 200–700/ha. This same parasitic wasp had previously averted famine for ∼ 20 million people in Africa. Our work emphasizes how beneficial (pest-controlling) insects help meet food production needs while benefiting farmers’ pockets, global commodity trade, and the environment.