The effects of chlorogenic acid on larval survival and growth of the tobacco budworm Heliothis virescens and larval susceptibility to Helicoverpa zea nucleopolyhedrovirus (HzSNPV) were studied with an artificial diet and transgenic tobacco Nicotiana tabacum. Survival of neonates on over- or underexpressed phenylalanine ammonia-lyase (PAL) transgenic tobacco lines was positively correlated with the level of chlorogenic acid. Larval weight was not correlated with the level of chlorogenic acid in tobacco foliage. On the other hand, larval weights on artificial diet supplemented with chlorogenic acid were negatively correlated with chlorogenic acid concentration. Second instars treated on virus-treated (10 occlusion bodies/larva) tobacco leaf disks for 24 hr and then reared on tobacco leaves showed higher survival time and increased mortality on lines with increasing levels of chlorogenic acid. However, viralrelated larval mortality on artificial diet was negatively correlated with dietary chlorogenic acid. These results illustrate the inadequacy of artificial diet studies in establishing causal relationships among plant chemistry, herbivores, and natural enemies.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics