Volatiles from Intact and Lygus-Damaged Erigeron annuus (L.) Pers. are Highly Attractive to Ovipositing Lygus and its Parasitoid Peristenus relictus Ruthe

Abstract

Trap cropping and biological control can provide a sustainable means of controlling insect pests. Insects in the genus Lygus (Hemiptera: Miridae) are major pests on cotton and horticultural crops throughout the United States, and pesticide resistance within Lygus populations necessitates more sustainable long-term management techniques. Here, we explore behavioral responses of Lygus bugs (L. rubrosignatus Knight) and an introduced parasitoid, Peristenus relictus (Hymenoptera: Braconidae), to a common field edge plant, Erigeron annuus, which has the potential to serve as a trap host. Erigeron annuus is attractive to Lygus in the field, with Lygus preferentially moving to Erigeron patches compared to more abundant cotton plants. To determine the role of odor cues in mediating this attraction, we collected volatiles from E. annuus with and without Lygus damage, and then tested the attractiveness of these volatiles vs. those of cotton to Lygus females and female P. relictus wasps using Y-tube and wind tunnel bioassays. We found that undamaged E. annuus emits high concentrations of a complex volatile blend (60+ compounds), with novel compounds induced and constitutive compounds up-regulated in response to damage. Additionally, both female Lygus bugs and female P. relictus wasps are highly attracted to E. annuus volatiles over those of cotton in almost every combination of damage treatments. Our results suggest that Erigeron annuus would be an effective trap plant to control Lygus in cotton, since it is highly attractive to both the pest and its natural enemy.

Herbivore‐induced plant volatiles: targets, perception and unanswered questions

“…The idea of odour-mediated tritrophic interactions has been less controversial than the concept of 'talking trees': multiple parasitoids and predators use plant-derived VOCs (which usually, but not always, are more strongly emitted after herbivory) to locate their herbivore prey (Kaplan, 2012a;Halloran et al, 2013;Penaflor & Bento, 2013;Vieira et al, 2013) or are attracted to HI-VOCs such as methyl salicylate (MeSA), linalool, or b-caryophyllene (James, 2003;Mallinger et al, 2011;Xiao et al, 2012). These effects can enhance the rates of predation and parasitism of herbivores (Khan et al, 1997;Thaler, 1999;Mallinger et al, 2011;Kaplan, 2012a;Uefune et al, 2012) and thereby reduce the numbers of herbivores on a plant (Kessler & Baldwin, 2001;Mallinger et al, 2011).…”

Volatile fragrances associated with flowers mediate host plant alternation of a polyphagous mirid bug

“…Host plant phenology appears to mediate, at least in part, between-host dispersal by these mirids so that hosts in the reproductive period are generally favored 11 . Host plant chemical cues play an important role in host recognition, finding, and acceptance by these mirids 16 17 18 19 . Moreover, the role of plant volatiles alone or in combination with insect-derived compounds extends to the next trophic level to guide host finding by mirid natural enemies 20 21 .…”

N-(18-Hydroxylinolenoyl)-l-Glutamine: A Newly Discovered Analog of Volicitin in Manduca sexta and its Elicitor Activity in Plants

“…The two newest fully developed leaves were scratched in the middle, crosswise, with a razor and treated with 20 l of elicitor solution (1 nmol of each elicitor in phosphate buffer), and placed into a VOC collection chamber. The chambers consisted of a modified Pyrex bottle (7 l) with a Teflon stopper with an inlet for 8 charcoal filtered air (1.5 l/min) and an aluminum guillotine at the bottom of the chamber(Halloran et al, 2013). The plant remained in its growing container and the stem was wrapped in cotton with the guillotine surrounding the stem.VOC collection and GC analysis.…”