Role of the plant–conspecific complex in host location and intra‐specific communication of Lygus rugulipennis

Abstract

Wind tunnel and vertical open Y-shaped olfactometer studies are used to test whether volatile cues from the host plant ( Vicia faba ), from conspecific bugs, and from a plant -conspecifics combination, would elicit behavioural responses in mated males and females of Lygus rugulipennis . In the olfactometer, females move towards volatiles from healthy plants but they do not respond to volatiles released by ovipositionand/or feeding-damaged plants without conspecifics, nor to conspecifics alone. Both in the wind tunnel and olfactometer, females respond to volatiles emitted by the plantinsect complex. By contrast, in the wind tunnel, both sexes move significantly towards damaged host plants, even if the presence of conspecifics on these plants enhances only the female response. However, the presence of eggs from conspecifics on host plants reduces the responses of both sexes in the wind tunnel. Finally, males, as well as females, are less responsive to conspecifics alone compared with damaged plants, especially when conspecifics are present on the host plants (host plant -Lygus complex). The results suggest that volatiles emitted by plants and conspecifics influence L. rugulipennis behaviour, giving information to both sexes on the presence of suitable host plants that have been colonized by other conspecifics acting as pioneers, or providing information on the presence of an already exploited host plant (presence of eggs), thus preventing competition. Males also can use this information to increase the probability of encountering mature females.

Plant Volatiles Influence Electrophysiological and Behavioral Responses of Lygus hesperus

“…Attraction was observed in L. hesperus females towards several constitutive and inducible plant volatiles. These chemical cues may help females locate plants that are suitable hosts for feeding, oviposition, and feeding of offspring (Groot et al 1999;Innocenzi et al 2004Innocenzi et al , 2005Frati et al 2008). In comparison, repellency was observed commonly in L. hesperus males in response to several plant volatiles.…”

“…Our results unlikely are due simply to the amount of compound used in the behavioral experiments but instead to the way the insect perceives each volatile because emission rates were not correlated with the insect's response. Likewise, L. rugulipennis females generally were more responsive than males to host plant and conspecific odors in a wind tunnel and vertical open Y-track olfactometer (Frati et al 2008). Although we refer to the bugs used in this study as 'naïve', they were, in fact, reared on hosts (green beans and carrots) that might have produced volatiles to which the bugs became conditioned prior to the olfactometer trials.…”

Attraction of Lygus rugulipennis and Adelphocoris lineolatus to synthetic floral odour compounds in field experiments in Hungary

“…Fujii et al 2010), including the North American Lygus species as well (Blackmer et al 2004;Whitbey 1999). Also, for the European tarnished plant bug, it was shown in olfactometer and wind tunnel experiments, that host plant volatiles provided an important stimulus for the species (Frati et al 2008). Some of our previous findings indicated that phenylacetaldehyde, a general floral odour compound may attract the European tarnished plant bug (unpublished data).…”

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

“…In contrast, in another mirid, Lygus hesperus Knight, only females are attracted to alfalfa volatiles, presumably to locate oviposition sites (Blackmer et al 2004). Furthermore, for Lygus rugulipennis Poppius, both sexes are attracted to odors from Vicia faba L. and that these responses are dependent on the presence of conspeciÞcs and whether the plant is damaged (Frati et al 2008(Frati et al , 2009. It is, Fig.…”