Plant Species- and Status-specific Odorant Blends Guide Oviposition Choice in the Moth Manduca sexta

Abstract

The reproductive success of herbivorous insects largely depends on the mother's oviposition preference. In nocturnal insects, olfaction is arguably the most important sensory modality mediating mate finding, foraging, and host location. In most habitats, gravid females select among a number of plants of varying suitability, yet assessment of the neuroethological mechanisms underlying odor-guided choice between host plants is rare. Using a series of behavioral, electrophysiological, and chromatographic analyses in the Hawk moth, Manduca sexta, we show that gravid females perform a hierarchical choice among host plants of different species and qualities using olfactory cues. Both relevant plant species and qualities can be distinguished by volatile profiles collected from the headspace of these plants, and olfactory sensilla on female antennae detect more than half of the about 120 analytically detected volatiles in host plant headspace samples. Although olfactory sensory neurons present in antennal sensilla are mainly broadly tuned to multiple host compounds, some sensilla exhibit species and condition-specific responses. In fact, species and quality can be distinguished by the physiologically active components alone. Our findings thus suggest that distinguishing characteristics of both host species and quality are already represented at the sensory periphery.

The plastic response of Manduca sexta to host and non-host plants

“…In laboratory experiments, Manduca shows no oviposition preference between Brassica oleracea and Nicotiana (Späthe et al, 2013). However, since oviposition in Manduca is guided by olfactory stimuli, and contact chemostimulation elicits deposition of eggs (Yamamoto et al, 1969), it may be that Brassica napus is not accepted for oviposition in the field.…”

“…The tobacco hornworm (Manduca sexta, henceforth called Manduca) has become an important model system in insect science (Baldwin, 2001;Riddiford et al, 2003;Shields and Hildebrand, 2001;Späthe et al, 2013). There are many studies on its biochemistry, behavior and physiology, and many studies on its host plant Nicotiana, yet few studies have investigated Manduca hostplant interactions at the molecular level.…”

Identification of olfactory receptor neurons in Uraba lugens (Lepidoptera: Nolidae) and its implications for host range

“…In a number of species, host location is guided by the trail of volatile compounds produced by their host plants, and the composition of the volatile compounds appears to be important in this process (Bengtsson et al, 2006;Webster et al, 2010b;Bruce and Pickett, 2011;Späthe et al, 2013), playing a critical role in both host recognition and non-host avoidance in phytophagous insects (Bruce and Pickett, 2011). Studies indicate that phytophagous insects such as Lepidoptera can recognize http://dx.doi.org/10.1016/j.jinsphys.2015.04.010 0022-1910/Ó 2015 Elsevier Ltd. All rights reserved.…”

Host Plant Species Differentiation in a Polyphagous Moth: Olfaction is Enough

“…1b). Using the same statistical approach, Späthe et al (2012) also found that the subset of volatiles perceivable by Manduca sexta was sufficient for them to differentiate Nicotiana attenuata and Dattura wrightii. Elements of olfactory profiles that are conserved among host plant individuals seem a necessary condition for the fine-tuned adaptation of a monophagous insect's olfactory system to their host's characteristic odor (Webster et al 2010), or for a polyphagous insect to be able to act upon previous olfactory experiences in the context of experienced host plant choice.…”