|SEITER, NICK - Arkansas State University|
|GREENE, JEREMY - Clemson University|
Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2016
Publication Date: 6/30/2016
Publication URL: http://handle.nal.usda.gov/10113/5418165
Citation: Portilla, M., Jones, W.A., Perera, O.P., Seiter, N., Greene, J., Luttrell, R.G. 2016. Estimation of median lethal concentration of three isolates of Beauveria bassiana for control of Megacopta cribraria (Heteroptera: Plataspidae) bioassayed on solid Lugys Spp. Diet². Insects. 7(3):31. doi: 10.3390/insects7030031.
Interpretive Summary: Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), is native to Asia. It was discovered in 2009 in the US feeding on kudzu, Pueraria montana (Lour) Merr. (Fabaceae) an economically important invasive vine. The virulence of three strains of an entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin (Sordariomycetes: Hypocrales) including the Mississippi Delta native strain NI8 ARSEF 8889 (NI8) isolated from Lygus lineolaris (Palisot de Beauvois), the commercial strain GHA or BotaniGard®, and a strain KUDSC-001 ARSEF 13136 isolated from M. cribraria (KUDSC) were bioassayed on kudzu bug adults at two different times post field collection of the insects. Younger adults (8 days after collection) were treated with NI8 and GHA strains and older adult (50 days after collection) were treated with NI8, GHA and KUDSD. Higher test concentrations of NI8 and GHA strains caused kudzu bug mortality 2-d after treatment in younger adults and NI8, GHA, and KUDSC caused mortality 1-d after treatment on older adults. Lower concentrations (n x104, n x105) were not significantly different among strains. High variability in lethal dose (LD50) and lethal sporulation (LS50) responses was observed among adult ages. Dose-ratios for mortality and sporulation were significantly higher for young adults than those ratios found for old adults. Isolate GHA was less virulent than NI8 against young adults, but LD50 values of the three isolates did not differ in assays against older adults. LS50 values of KUDSC strain were significantly lower than NI8 and GHA values in old adults. Data presented showed the potential for management of kudzu bugs with the entomophatogenic fungus B. bassiana.
Technical Abstract: The entomopathogenic fungus Beauveria bassiana is a potential candidate for biological control of a variety of pests. The objectives of this study were isolate and identify the fungus from Kudzu bugs and determine its infectivity comparing with two highly pathogenic isolates including the Mississippi Delta strain NI8 known for its high virulence to Tarnished plant bugs and the commercial strain GHA under laboratory conditions. Recently, high incidences of B. bassiana were observed in collections of M. cribraria nymphs and adults from wild kudzu plants in Mississippi. Measured infections rates have been ranging from 10 to 95%. The kudzu strain KUDSC-001 (ARSEF 13136) used in this investigation was the first strain reported in North America infecting and killing M. cribraria on soybean plots. Data on B. bassiana lethal effects on M. cribraria is presented and evaluated.