Impact of extrafloral cotton nectaries on feeding behavior of young Heliothis virescens (Lepidoptera:Noctuidae) larvae

The allelochemical concentrations in extrafloral nectary tissues are similar to those in corresponding tissues of nectariless cottons. Variation exists among nectaried cotton lines in size of extrafloral nectaries. H. virescens (F.) larvae are not attracted to extrafloral nectar, but this nectar does appear to be a feeding stimulant. Extrafloral nectaries are important routes of entry by larvae damaging ovaries of cotton squares; however, larvae damaged equal numbers of pistils regardless of presence or absence of extrafloral nectaries. The artificial infestation of cotton terminals allowed for more natural feeding behavior of larvae than application of larvae directly to squares.