Increased long-flight activity triggered in beet armyworm by larval feeding on diet containing Cry1Ac protoxin
Language: 
English
Abstract: 

Evaluating ecological safety and conducting pest risk analysis for transgenic crops are vitally important before their commercial planting. The beet armyworm, Spodoptera exigua, a long-distance migratory insect pest, is not a direct target of transgenic Cry1Ac-expressing cotton in China, but nevertheless it has recently become an important pest. Migrants leaving their natal field arrive in other appropriate habitat far away in a short time, often followed by larval outbreaks. S. exigua has low susceptibility to Cry1Ac. However, our results from laboratory experiments identified (i) sublethal effects of Cry1Ac protoxin on larval development rate, larval and pupal weight, and adult lifetime fecundity, and (ii) increased long-flight behavior triggered by Cry1Ac which may contribute to larval outbreaks elsewhere. No significant differences in larval mortality, pupation rate, adult emergence rate, longevity, pre-oviposition period, or oviposition period were observed between controls and larvae fed on artificial diet incorporating a low concentration of Cry1Ac protoxin. The negative sublethal effects on some developmental and reproductive traits and lack of effect on others suggest they do not contribute to the observed severity of S. exigua outbreaks after feeding on Cry1Ac cotton. Interestingly, the percentage of long fliers increased significantly when larvae were reared on diet containing either of two low-dose treatments of Cry1Ac, suggesting a possible increased propensity to disperse long distances triggered by Cry1Ac. We hypothesize that negative effects on development and reproduction caused by Cry1Ac in the diet are offset by increased flight propensity triggered by the poor food conditions, thereby improving the chances of escaping adverse local conditions before oviposition. Increased long-flight propensity in turn may amplify the area damaged by outbreak populations. This phenomenon might be common in other migratory insect pests receiving sublethal doses of Bt toxins and warrants further study.

Author(s): 
Jiang, Xing Fu
Chen, Jian
Zhang, Lei
Sappington, Thomas W.
Luo, Li Zhi
Item Type: 
Journal Article
Publication Title: 
PloS One
Journal Abbreviation: 
PLoS ONE
Publication Date: 
2013
Publication Year: 
2013
Pages: 
e63554
Volume: 
8
Issue: 
5
ISSN: 
1932-6203
DOI: 
10.1371/journal.pone.0063554
Library Catalog: 
NCBI Published Medical (?)
Extra: 
PMID: 23675489 PMCID: PMC3652841

Turabian/Chicago Citation

Xing Fu Jiang, Jian Chen, Lei Zhang, Thomas W. Sappington and Li Zhi Luo. 2013. "Increased long-flight activity triggered in beet armyworm by larval feeding on diet containing Cry1Ac protoxin." PloS One 8: 5: e63554. 10.1371/journal.pone.0063554.

Wikipedia Citation

<ref> {{Cite journal | doi = 10.1371/journal.pone.0063554 | issn = 1932-6203 | volume = 8 | pages = e63554 | last = Jiang | first = Xing Fu | coauthors = Chen, Jian, Zhang, Lei, Sappington, Thomas W., Luo, Li Zhi | title = Increased long-flight activity triggered in beet armyworm by larval feeding on diet containing Cry1Ac protoxin | journal = PloS One | date = 2013 | pmid = | pmc = }} </ref>