TLC-Based Bioassay to Isolate Kairomones from Tea Tree Essential Oil That Attract Male Mediterranean Fruit Flies, Ceratitis capitata (Wiedemann)

Abstract

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) poses a major threat to fruit and vegetable production in the United States and throughout the world. New attractants and detection methods could improve control strategies for this invasive pest. In this study, we developed a method that combined thin-layer chromatography (TLC) of tea tree essential oil (TTO) (Melaleuca alternifolia) with short-range bioassays to isolate attractive kairomones for male C. capitata. After development, the TLC chromatogram indicated that TTO separated into five major spots, designated as zones 1 to 5. When the TLC plate was exposed to flies, zones 1 and 3 were strongly attractive to male C. capitata. To confirm activity, the developed TLC plate was cut into five zones which were then tested in short-range bioassays. Again, flies were observed to aggregate around zones 1 and 3, which corresponded with Rf values of 0.93 and 0.59. In addition, zones 1 to 5 were separated using preparative-TLC, and olfactory responses to volatile emissions from the five fractions were quantified by electroantennography (EAG). Highest amplitude EAG responses were recorded with fractions 1 and 3, further supporting the bioactivity of these samples. In conclusion, a TLC-based bioassay system can provide an effective, rapid screening protocol for initial isolation of insect kairomones from complex mixtures such as essential oils or plant extracts. Further analysis of TTO fractions 1 and 3 is needed to identify the specific constituents attractive to male C. capitata.

Blue Tansy Essential Oil: Chemical Composition, Repellent Activity Against Aedes aegypti and Attractant Activity for Ceratitis capitata

“…15,19 In short-range laboratory bioassays with male C. capitata, there were significant differences in mean behavioral response to five essential oil treatments (F = 10.087; df = 4,20; P < .001). Attraction to BTEO was significantly lower than that observed with two positive controls, that is, tea tree oil (TTO) Melaleuca alternifolia (Maiden and Betche) Cheel., 25 and ginger bush Tetradenia riparia (Hochst.) Codd essential oil (TREO) 26 ( Figure 2).…”

“…The source of insects, rearing protocols and experiment design for laboratory bioassays were as described previously. [25][26][27] All observations were carried out at room temperature in small collapsible cages (20.3 × 20.3 × 20.3 cm) into which 50 flies were introduced 1 hour prior to the start of each experiment. Tests were initiated by introducing a Petri dish (53 mm diameter × 12 mm height) with a filter paper disk containing a sample of essential oil (10 µL of a 10% dilution in acetone).…”

“…In recent years, reduced-risk agents such as essential oils and natural ("green") volatile compounds have gained increased recognition as key elements for improving integrated pest management strategies. 8,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Tanacetum annuum L. (synonyms: Balsamita annua L., B. multifida Clemente, and Chrysanthemum annuum [L.] Fiori) is a member of the giant family of Asteraceae (Compositae). Members of the genus Tanacetum have been used for medicinal purposes for decades due to their wide range of pharmacological and chemical properties as well as excellent medicinal values.…”

Chemical Composition of Essential Oil FromTetradenia ripariaand Its Attractant Activity for Mediterranean Fruit Fly,Ceratitis capitata

“…In short-range laboratory bioassays, the response of male C. capitata to TREO was assessed relative to response with a strong medfly attractant, tea tree oil (TTO), 21 and a mild medfly attractant, mastic gum essential oil (MGEO, 3 sources) 31 ( Figure 2). There were significant differences in mean attraction of males among the 5 treatments (F = 10.543; df = 420; P < 0.001).…”

“…Source of insects, rearing procedures, and short-range laboratory bioassays were as described previously. 21,31 All observations were carried out at room temperature in small collapsible cages (20.3 × 20.3 × 20.3 cm) into which 50 flies were introduced 1 hour prior to the start of each experiment. Assays were initiated by introducing a Petri dish (53 mm diameter × 12 mm height) containing the test chemical (10 µL of a 10% dilution in acetone) applied to a filter paper disk (Whatman #1, 3.5 cm diameter).…”