Abstract
Biological control, a globally-important ecosystem service, can provide long-term and broad-scale suppression of invasive pests, weeds and pathogens in natural, urban and agricultural environments. Following (few) historic cases that led to sizeable environmental up-sets, the discipline of arthropod biological control has—over the past decades—evolved and matured. Now, by deliberately taking into account the ecological risks associated with the planned introduction of insect natural enemies, immense environmental and societal benefits can be gained. In this study, we document and analyze a successful case of biological control against the cassava mealybug, Phenacoccus manihoti (Hemiptera: Pseudococcidae) which invaded Southeast Asia in 2008, where it caused substantial crop losses and triggered two- to three-fold surges in agricultural commodity prices. In 2009, the host-specific parasitoid Anagyrus lopezi (Hymenoptera: Encyrtidae) was released in Thailand and subsequently introduced into neighboring Asian countries. Drawing upon continental-scale insect surveys, multi-year population studies and (field-level) experimental assays, we show how A. lopezi attained intermediate to high parasitism rates across diverse agro-ecological contexts. Driving mealybug populations below non-damaging levels over a broad geographical area, A. lopezi allowed yield recoveries up to 10.0 t/ha and provided biological control services worth several hundred dollars per ha (at local farm-gate prices) in Asia’s four-million ha cassava crop. Our work provides lessons to invasion science and crop protection worldwide. Furthermore, it accentuates the importance of scientifically-guided biological control for insect pest management, and highlights its potentially large socio-economic benefits to agricultural sustainability in the face of a debilitating invasive pest. In times of unrelenting insect invasions, surging pesticide use and accelerating biodiversity loss across the globe, this study demonstrates how biological control—as a pure public good endeavor—constitutes a powerful, cost-effective and environmentally-responsible solution for invasive species mitigation.
| Original language | English (US) |
|---|---|
| Article number | e5796 |
| Journal | PeerJ |
| Volume | 2018 |
| Issue number | 10 |
| DOIs | |
| State | Published - 2018 |
Bibliographical note
Funding Information:This manuscript presents original data-sets, generated through fully collaborative research, with trials jointly conceptualized, defined and executed by national program staff and CIAT personnel. This paper is dedicated to the memory of Drs. RJ O’Neil, A. Winotai and AC Bellotti—pioneers in the field of insect biological control. We are grateful to collaborators at China Academy of Tropical Agricultural Sciences CATAS, for sharing monitoring records from Yunnan province. This initiative was conducted as part of an EC-funded, IFAD-managed, CIAT-executed programme (CIAT-EGC-60-1000004285), while additional funding was provided through the CGIAR-wide Research Program on Roots, Tubers and Banana (CRP-RTB). Activities in Thailand and Indonesia during 2017 were finalized using own resources of Kris AG Wyckhuys. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The following grant information was disclosed by the authors: CIAT-executed programme: CIAT-EGC-60-1000004285. CGIAR-wide Research Program. Tubers and Banana (CRP-RTB). Kris AG Wyckhuys.
Publisher Copyright:
Copyright 2018 Wyckhuys et al.
Keywords
- Ecological intensification
- Ecological safety
- Ecosystem services
- Insect biological control
- Insect parasitism
- Invasion biology
- Sustainable agriculture
- Tropical agro-ecosystems
