Assessing Potential Impact of Bt Eggplants on Non-Target Arthropods in the Philippines

PLoS One. 2016 Oct 31;11(10):e0165190. doi: 10.1371/journal.pone.0165190. eCollection 2016.

Abstract

Studies on potential adverse effects of genetically engineered crops are part of an environmental risk assessment that is required prior to the commercial release of these crops. Of particular concern are non-target organisms (NTOs) that provide important ecosystem services. Here, we report on studies conducted in the Philippines over three cropping seasons with Bt eggplants expressing Cry1Ac for control of the eggplant fruit and shoot borer (EFSB), Leucinodes orbonalis, to examine potential effects on field abundance, community composition, structure and biodiversity of NTO's, particularly non-target arthropod (NTA) communities. We document that many arthropod taxa are associated with Bt eggplants and their non-Bt comparators and that the number of taxa and their densities varied within season and across trials. However, we found few significant differences in seasonal mean densities of arthropod taxa between Bt and non-Bt eggplants. As expected, a lower abundance of lepidopteran pests was detected in Bt eggplants. Higher abundance of a few non-target herbivores was detected in non-Bt eggplants as were a few non-target beneficials that might control them. Principal Response Curve (PRC) analyses showed no statistically significant impact of Bt eggplants on overall arthropod communities through time in any season. Furthermore, we found no significant adverse impacts of Bt eggplants on species abundance, diversity and community dynamics, particularly for beneficial NTAs. These results support our previous studies documenting that Bt eggplants can effectively and selectively control the main pest of eggplant in Asia, the EFSB. The present study adds that it can do so without adverse effects on NTAs. Thus, Bt eggplants can be a foundational component for controlling EFSB in an Integrated Pest Management (IPM) program and dramatically reduce dependence on conventional insecticides.

MeSH terms

  • Animals
  • Arthropods / physiology*
  • Bacillus thuringiensis / metabolism*
  • Philippines
  • Soil
  • Solanum melongena / parasitology*
  • Solanum melongena / physiology*
  • Species Specificity

Substances

  • Soil

Grants and funding

This research was funded through the United States Agency for International Development (USAID Cooperative Agreement GDG-A-00-02-00017-00) to Cornell University Agricultural Biotechnology Support Project II (ABSPII), and matching funds from the Republic of the Philippines Department of Agriculture- Biotechnology Program Office (DA- Biotech BPO) and the University of the Philippine Los Banos (UPLB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.