Multimodal cues drive host-plant assessment in Asian citrus psyllid (Diaphorina citri).
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.
USDA-Agricultural Research Service, Subtropical Agricultural Research Center, Weslaco, TX, USA. joseph.patt@ars.usda.gov
Joseph M
JM
Patt
William G
WG
Meikle
Agenor
A
Mafra-Neto
Mamoudou
M
Sétamou
Robert
R
Mangan
Chenghai
C
Yang
Nasir
N
Malik
John J
JJ
Adamczyk
D000818:Animals; D001522:Behavior, Animal; D032083:Citrus paradisi; D032084:Citrus sinensis; D003116:Color; D005260:Female; D006430:Hemiptera / Q000187:drug effects / Q000502:physiology*; D008297:Male; D032101:Murraya; D012903:Smell; D013045:Species Specificity; D013395:Sucrose / Q000494:pharmacology; D055697:Taste Perception; D013729:Terpenes / Q000494:pharmacology; D013781:Texas; D014796:Visual Perception; D055549:Volatile Organic Compounds / Q000494:pharmacology
D013729:Terpenes; D055549:Volatile Organic Compounds; D013395:Sucrose