Plant Volatiles Influence Electrophysiological and Behavioral Responses of Lygus hesperus

Abstract

Previous laboratory studies have shown that the mirid Lygus hesperus is attracted to volatiles emitted from alfalfa; feeding damage increases the amounts of several of these volatiles, and visual cues can enhance attraction further. The present study tested single plant volatiles in electrophysiological and behavioral trials with L. hesperus. Electroantennogram (EAG) analyses indicated that antennae responded to most plant volatiles included in the test, and that when gender differences were observed, males usually were more responsive than females. Antennal responses to the alcohols ((E)-3-hexenol, (Z)-3-hexenol, 1-hexanol), the acetate (E)-2-hexenyl acetate, and the aldehyde (E)-2-hexenal were among the strongest. Moderate responses were observed for (E)-beta-ocimene, (E,E)-alpha-farnesene, (+/-)-linalool, and methyl salicylate. A dose dependent response was not observed for several terpenes (beta-myrcene, beta-caryophyllene, (+)-limonene, or both (R)-(+)- and (S)-(-)-alpha-pinenes). EAG responses, however, were not always consistent with behavioral assays. In Y-tube bioassays, males did not exhibit a positive behavioral response to any of the compounds tested. Instead, males were repelled by (E)-2-hexenyl acetate, (+/-)-linalool, (E,E)-alpha-farnesene, and methyl salicylate. In contrast, female L. hesperus moved upwind towards (R)-(+)-alpha-pinene, (E)-beta-ocimene, and (E,E)-alpha-farnesene, and showed a negative response towards (Z)-3-hexen-1-ol, (S)-(-)-alpha-pinene, and methyl salicylate. This study emphasizes the use of multiple approaches to better understand host plant finding in the generalist herbivore L. hesperus.

Cashew Volatiles Mediate Short-Range Location Responses in <I>Pseudotheraptus wayi</I> (Heteroptera: Coreidae)

“…Interestingly, in coupled GC-EAD and EAG analyses, we found that male antennae detected cashew leaf volatile components more strongly than those of females. Similar observations have been reported in the related family, Miridae, for example, Lygus lineolaris (Palisot de Beauvois) (Chinta et al 1994), Lygocoris pabulinus (L.) (Groot et al 1999), and Lygus hesperus Knight (Williams et al 2010). This suggests that some male phytophagous heteropterans may possess more plant odor receptors than females, a hypothesis that may be supported by previous Þndings that the distal most hairy antennomere of adult male P. wayi is Ϸ1.5 times longer than that found in females (Egonyu et al 2013b).…”

Feeding-induced rearrangement of green leaf volatiles reduces moth oviposition

“…Electrophysiological experiments revealed that this compound elicited many responses in OSNs on the female M. sexta antenna: 60% of the tested sensilla (Spaethe et al, 2013) as well as 21 of 34 cells in the female AL (Kuebler et al, 2011) responded to this compound. ( E )-2-hexenyl acetate, in contrast, has rarely been reported in insect-plant interactions (Whitman and Eller, 1990; Quiroz and Niemeyer, 1998; Williams et al, 2010), aside from its release among other GLVs after larval feeding of M. sexta on N. attenuata (Allmann and Baldwin, 2010) as an indication of actual larval damage. Thus, the presence of each structural isomer contains specific information but at different levels of resolution and in different contexts.…”

Electrophysiological and behavioral characterization of bioactive compounds of the Thymus vulgaris, Cymbopogon winterianus, Cuminum cyminum and Cinnamomum zeylanicum essential oils against Anopheles gambiae and prospects for their use as bednet treatments

“…These results may suggest involvement of different sensory neurons or another pathway than antennal reception in the phenomena of how repellents function. Inconsistencies between electrophysiological and behavioral results have been previously reported [22, 23], and underscore the value of using a variety of research approaches when studying complex behavior such as repellency at the level of the whole organism. In their study on Aedes aegypti , Dekker et al [24] examined the repellent effect of electroantennographic detection (EAD)-active compounds of the headspace extracts of crushed Ocimum forskolei .…”