SPECIAL SESSION: Mycotoxin Mayhem: Insect Pests In The Mix
Stink bug-Fusarium interactions and their associations with mycotoxin contamination of corn in the mid-Atlantic U.S.
Hillary Mehl - Virginia Tech Tidewater AREC. Nathan Kleczewski- University of Illinois, Kelly Hamby- Department of Entomology, University of Maryland, Joseph Opoku- Virginia Tech Tidewater AREC
Stink bugs, including invasive brown marmorated stink bug (BMSB) (Halyomorpha halys) and native brown stink bug (Euschistus servus), can severely damage crops including field corn. Frequency and size of stink bug infestations in mid-Atlantic U.S. corn fields have increased, and there is growing concern that this may contribute to reductions in grain quality. A correlation between BMSB damage and fumonisin contamination was identified, and the ability of BMSB to increase Fusarium infection and fumonisin contamination in corn was demonstrated in field experiments. Subsequent studies demonstrated a similar synergistic association between native brown stink bugs and fumonisin contamination of corn. Potential for stink bugs to vector mycotoxigenic Fusarium spp. was examined, and Fusarium was isolated from 34% of stink bugs collected from corn fields. Among these isolates, 78% were fumonisin-producing species including F. verticillioides (Fv) and F. proliferatum, and 18% were trichothecene-producers. Furthermore, identical SSR haplotypes of Fv were isolated from stink bugs and corn collected from the same field. In laboratory experiments, stink bugs were able to transmit Fv to non-infected corn ears after feeding on Fv-infected corn. Thus, strategies that control both the pest (stink bug) and pathogen (Fusarium) must be implemented to mitigate risks of mycotoxin contamination in corn.