Multimodal Cues Drive Host-Plant Assessment in Asian Citrus Psyllid (Diaphorina citri)

Abstract

Asian citrus psyllid (Diaphorina citri) transmits the causal agent of Huanglongbing, a devastating disease of citrus trees. In this study we measured behavioral responses of D. citri to combinations of visual, olfactory, and gustatory stimuli in test arenas. Stimuli were presented to the psyllids in droplets or lines of an emulsified wax formulation in two different arena types in no-choice tests. First, when placed on a colored ring situated halfway between the center and perimeter of a petri dish, D. citri spent more time on yellow versus gray rings; however, this response disappeared when either gray or yellow wax droplets were applied. When the psyllids were presented with droplets scented with terpenes, the response to both scent and color was increased. The addition of a dilute (≍0.1 M) sucrose solution to the wax droplets increased the magnitude of D. citri responses. Next, groups of D. citri were placed on plastic laboratory film covering a sucrose solution, to mimic a leaf surface. Test stimuli were presented via two 'midribs' made from lines of emulsified wax formulation. Probing levels were measured as a function of color saturation and scent composition, and concentration. The test scents were based on qualitatively major volatiles emitted by Murraya paniculata (L.) Jack, Citrus aurantifolia (Christm.) Swingle, and C. sinensis (L.) Osbeck. The highest probing response was observed on the middle concentration (20-μl scent/10 ml wax formulation) of the C. aurantifolia-scented wax lines. Results indicate that there are interactive effects between the different sensory modalities in directing host-plant assessment behavior.

Related but not alike: not all Hemiptera are attracted to yellow

“…Our results are consistent with field studies in which higher catches of psyllids were obtained using yellow and green sticky traps (Mensah and Madden, 1992;Brennan and Weinbaum, 2001;Al-Jabr and Cranshaw, 2007;Hall et al, 2010). The current findings also complement lab studies that have shown that olfactory responses to host plant volatiles are enhanced when experienced in conjunction with green or yellow stimuli (Wenninger et al, 2009;Patt et al, 2011). By contrast, Anoeconeossa bundoorensis and Glycaspis brimblecombei strongly preferred "red" stimuli.…”

“…This is mostly due to the fact that psyllids, like aphids, are presumed to be responsive to yellow-green (Mensah and Madden, 1992;Brennan and Weinbaum, 2001;Al-Jabr and Cranshaw, 2007;Hall et al, 2010), and therefore research has concentrated more on their olfactory responses (Valterovà et al, 1997;Soroker et al, 2004;Gross and Mekonen, 2005;Mayer et al, 2008;Patt and Sétamou, 2010). However, as in aphids, psyllids exhibit only weak chemotactic responses in the absence of visual cues (Hodkinson, 1974;Wenninger et al, 2009;Patt et al, 2011) and seem to possess an even less developed olfactory apparatuswhich may only operate in host alternating species. An obvious limiting factor in the understanding of visual mechanisms in psyllids in psyllids is small size and the softness of their eyes, which has impeded the acquisition of physiological data.…”

The Influence of Maturity and Variety of Potato Plants on Oviposition and Probing ofBactericera cockerelli(Hemiptera: Triozidae)

“…One Þnal explanation for an age effect on probing/feeding but not on oviposition is sensory. TPPs respond to multiple types of cues, including visual (Demirel andCranshaw 2006, Wenninger et al 2009), olfactory (Wenninger et al 2009, Diaz-Montano andTrumble 2013), and sensory organs on the mouth parts (Butler et al 2012); these cues also interact (Patt et al 2011). Therefore, TPPs may choose feeding based on different cues than are used for oviposition and age may not inßuence these cues.…”

Elevated anthocyanins protect young Eucalyptus leaves from high irradiance but also indicate foliar nutritional quality to visually attuned psyllids

“…Unfortunately, there is only limited behavioural evidence of psyllid attraction to host plant volatiles. Most studies involving pest species such as the Asian citrus psyllid (Diaphorina citri Kuwayama) or the pear psyllid [Cacopsylla bidens (Šulc)] revealed poor responsiveness and/or limited attraction to host plant volatiles that often required the presence of a visual stimulus to be expressed (Soroker et al, 2004;Wenninger et al, 2009;Patt & Sétamou, 2010;Patt et al, 2011). Interestingly, stronger olfaction-driven attraction has been observed in systems in which host odour is altered either by phytopathogen infection or by the feeding of a high number of conspecifics.…”