The sorghum chafer, Pachnoda interrupta, (Coleoptera: Scarabaeidae) is arnpolyphagous herbivore and an important pest of sorghum (Sorghum bioclor). In thisrnthesis work, plant volatile compounds from different hosts were identified with thernpurpose of using it as bait in traps for monitoring and/or control of P. interrupta adults.rnBehavioral and antennal responses of the sorghum chafer, Pachnodarninterrupta (Olivier) were tested to eugenol, methyl salicylate, methyl anthranilate,rnisoamyl acetate and butyl butyrate. In the field, all odor-baited traps except isoamylrnacetate applied on cotton dispensers, were significantly more attractive than unbaitedrntraps. All compounds, except isoamyl acetate, elicited dose dependentrnelectrophysiological responses from both male and female antennae. Dispenser typern(cotton wick or rubber septum), trap location (inside or outside sorghum fields) andrnseason (mating/July or feeding/September) affected the performance of differentrncompounds as lures. In July, methyl salicylate applied on cotton was the mostrnattractive lure, whereas the most attractive treatments in September were eugenolrnand isoamyl acetate on rubber septum.rnHeadspace volatiles were collected from sorghum, Sorghum bicolor (Poaceae)rnand abutilon, Abutilon figarianum (Malvaceae). Combined gas chromatographyelectroantennographicrndetection (GC-EAD) analysis was carried out on the antennaernof both sexes of P. interrupta. Compounds active in GC-EAD were identified byrncoupled gas chromatography-mass spectrometry (GC-MS) as (Z)-3-hexen-1-ol,rntridecane, 1-octen-3-ol, and 1-octanol from sorghum. From abutilon, (Z)-3-hexen-1-ol,rntetradecane, methyl salicylate and methyl anthranilate were identified. Similarly, EADactiverncompounds were identified from ripe banana as: ethyl butanoate, butyl isobutanoate, isobutyl isobutanoate, isopentyl isobutanoate, isoamyl butanoate, cis-3-rnhexyl-2-methyl butanoate and 2-heptyl butanoate.rnIn the field, there was no significant difference in number of beetles caught inrntraps baited with individual sorghum compounds as compared to a blend of all fourrncompounds in ratios mimicking the ones found in the sorghum extract. However,rnwhen methyl salicylate and/or eugenol were added to the blend, trap catchesrnincreased significantly. Similar results were obtained when eugenol was added to thernsynthetic abutilon blend in this study.rnBehavioral responses tested using the Y-tube olfactometer showed nornsignificant different in response between the banana extract and the blend ofrnsynthetic compounds. This indicates that the compounds identified are behaviorallyrnrelevant and can be used as potential candidate for further field test.rnScanning electron microscopy (SEM) revealed four morphological types ofrnsensilla in the sorghum chafter, Pachnoda interrupta: grooved peg, smooth peg,rngrooved placodea, and smooth placodea. Olfactory receptor neurons (ORNs) werernscreened for response in single sensillum recordings with a set of 80 food-relatedrncompounds. From the 50 responding ORNs, 23 classes were identified. The classesrnwere tuned to single compounds or sets of structurally and functionally similarrncompounds. The different ORN classes responded to green leaf volatiles (GLVs),rnflower and fruit odours and fermentation products. This indicates a sensory strategyrnfor food search where multiple classes of ORNs each have a narrow detectionrnwindow. Such a strategy could rely on common compounds present in hosts such asrnfruit or flowers, which advertise to symbionts for pollination and seed-dispersal withrnstereotyped odour signals.