Frankliniella fusca and Frankliniella occidentalis response to thrips-active Cry51Aa2.834_16 Bt cotton with and without neonicotinoid seed treatment

Understanding the potential impact of continued seed treatment use for resistance management in Cry51Aa2.834_16 Bt cotton against Frankliniella fusca

“…However, the mechanism of MON 88702 activity creates added challenges to resistance management in the field. Specifically, recent studies have shown that MON 88702 acts by a non-lethal antixenosis leading to suppressed oviposition that results in fewer F. fusca larvae developing on MON 88702 cotton [13][14][15][16]. Similar non-lethal suppression of oviposition by adult F. fusca in conjunction with acute larval toxicity have been documented for neonicotinoid seed treated (NST) cotton [17][18][19].…”

“…Both MON 88702 cotton and neonicotinoid seed treatments have strong antixenotic effects on adult F. fusca resulting in large reductions in oviposition and larval establishment on cotton, even in the presence of alternative host plants. While MON 88702 alters feeding behavior and reduces oviposition of adults, it has minimal impacts on adult and larval survival [13][14][15][16]. Both imidacloprid and thiamethoxam applied as seed treatments also have minimal impact on survival of adult F. fusca and dramatically reduce oviposition on treated cotton seedlings; however, they also cause moderate to high levels of larval mortality [17][18][19].…”

“…fusca resulting in large reductions in oviposition and larval establishment on cotton, even in the presence of alternative host plants. While MON 88702 alters feeding behavior and reduces oviposition of adults, it has minimal impacts on adult and larval survival [ 13 – 16 ]. Both imidacloprid and thiamethoxam applied as seed treatments also have minimal impact on survival of adult F .…”

“…Specifically, recent studies have shown that MON 88702 acts by a non-lethal antixenosis leading to suppressed oviposition that results in fewer F . fusca larvae developing on MON 88702 cotton [ 13 – 16 ]. Similar non-lethal suppression of oviposition by adult F .…”

Feeding behavior of Frankliniella fusca on seedling cotton expressing Cry51Aa2.834_16 Bt toxin

“…9,10 In no-choice experiments, they oviposited less on MON 88702 than on non-Bt cotton. 10,11 A previous study of L. lineolaris feeding behavior on MON 88702 showed antifeedant activity, wherein L. lineolaris tended to spend more time engaged in pre-oral digestion activity (i.e. cell rupturing by enzymatic, macerating saliva) and exhibited shorter periods of ingestion relative to insects that fed on non-Bt cotton.…”