Back to Search
Start Over
Performance of Bt-susceptible and -heterozygous dual-gene resistant genotypes of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in seed blends of non-Bt and pyramided Bt maize.
- Source :
-
Insect science [Insect Sci] 2021 Aug; Vol. 28 (4), pp. 1147-1158. Date of Electronic Publication: 2020 Aug 06. - Publication Year :
- 2021
-
Abstract
- A seed blend refuge has been implemented in the U.S. Corn Belt for Bt maize resistance management. The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a target pest of Bt maize in the Americas. The larvae of this pest are mobile, which may affect the efficacy of seed blend refuges. In this study, field and greenhouse trials were conducted to determine the performance of Bt-susceptible (aabb) and -heterozygous dual-gene-resistant (AaBb) genotypes of S. frugiperda in seed blends of non-Bt and pyramided Bt maize. Three field trials evaluated larval survival, larval growth, and plant injury with aabb in seed blends of Bt maize expressing Cry1A.105/Cry2Ab2/Vip3A with 0-30% non-Bt seeds. Greenhouse tests investigated the performance of aabb and AaBb in seed blends of Cry1A.105/Cry2Ab2 with 0-30% non-Bt seeds. In pure non-Bt maize plots, after 9-13 d of neonates being released on the plants, 0.39 and 0.65 larvae/plant survived with leaf injury ratings of 4.7 and 5.9 (Davis's 1-9 scale) in the field and greenhouse, respectively. In contrast, live larvae and plant injury were virtually not observed on Bt plants across all planting patterns. Larval occurrence and plant injury by aabb on non-Bt plants were similar between seed blends and pure non-Bt plantings, suggesting that the blended refuges could provide an equivalent susceptible population as structured refuge under the test conditions. In the greenhouse, the two insect genotypes in seed blends performed similarly, indicating that the seed blends did not provide more favorable conditions for AaBb over aabb. The information generated from this study should be useful in managing S. frugiperda and evaluating if send blends could be suitable refuge options for Bt resistance management in the regions where the insect is a primary target pest.<br /> (© 2020 The Authors. Insect Science published by John Wiley & Sons Australia, Ltd on behalf of Institute of Zoology, Chinese Academy of Sciences.)
- Subjects :
- Animals
Bacillus thuringiensis Toxins genetics
Bacterial Proteins genetics
Crops, Agricultural genetics
Endotoxins genetics
Genotype
Hemolysin Proteins genetics
Insecticide Resistance genetics
Larva growth & development
Moths genetics
Moths growth & development
Plants, Genetically Modified
Spodoptera drug effects
Spodoptera genetics
Bacillus thuringiensis Toxins pharmacology
Endotoxins pharmacology
Hemolysin Proteins pharmacology
Pest Control, Biological
Spodoptera growth & development
Zea mays genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1744-7917
- Volume :
- 28
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Insect science
- Publication Type :
- Academic Journal
- Accession number :
- 32662592
- Full Text :
- https://doi.org/10.1111/1744-7917.12850