Effects of transgenic Bacillus thuringiensis cotton on insecticide use, heliothine counts, plant damage, and cotton yield: A meta-analysis, 1996-2015

PLoS One. 2018 Jul 19;13(7):e0200131. doi: 10.1371/journal.pone.0200131. eCollection 2018.

Abstract

The primary management tactic for lepidopteran pests of cotton in the United States of America (USA) is the use of transgenic cotton that produces Bacillus thuringiensis Berliner (Bt) toxins. The primary target pests of this technology are Helicoverpa zea (Boddie) and Heliothis virescens (F.) in the eastern and central Cotton Belt of the USA. Concerns over the evolution of resistance in H. zea to Bt toxins and scrutiny of the necessity of Bt crops has escalated. We reviewed published and unpublished data from field trials of Bt cotton in the eastern and central Cotton Belt of the USA through 2015 to evaluate the effectiveness of Bt cotton (Bollgard, Bollgard II, WideStrike, WideStrike 3, and TwinLink). Bt cotton reduced insecticide usage, reduced heliothine pest numbers and damage, and provided a yield benefit, but Bollgard II and WideStrike efficacy declined in the Midsouth over the period evaluated. In the Southeastern region, heliothine damage remained constant through 2015, but yield benefits declined from 2010 until 2015. Resistance of H. zea to several Bt toxins is the most plausible explanation for the observed changes in Bt cotton efficacy. The introduction of new Bt toxins such as found in Widestrike 3 and Twinlink may preserve the benefits of Bt crops. However, while both Widestrike 3 and Twinlink had less damage than Widestrike, damage levels of both were similar to Bollgard II.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Bacillus thuringiensis* / genetics
  • Bacterial Proteins / genetics*
  • Crops, Agricultural* / genetics
  • Crops, Agricultural* / metabolism
  • Insect Control
  • Insecticide Resistance
  • Insecticides / administration & dosage*
  • Moths* / drug effects
  • Pest Control, Biological
  • Plants, Genetically Modified* / metabolism
  • United States

Substances

  • Bacterial Proteins
  • Insecticides

Grants and funding

This project was partially funded through United States Department of Agriculture Specific Cooperative Agreement USDA-SCA 58-6402-3-038 received by FM. This agreement provided support in the form of salary for one author (DF). NL was the USDA representative overseeing the agreement who participated as a co-author from idea development through paper review. Additional support came from Mississippi State University Hatch Project MIS-311280 for the support of FM.