Effects of Methyl Eugenol Feeding on Mating Compatibility of Asian Population of Bactrocera dorsalis (Diptera: Tephritidae) with African Population and with B. carambolae

Consumption of β-Caryophyllene Increases the Mating Success of Bactrocera zonata Males (Diptera: Tephritidae)

The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), is an economically important polyphagous quarantine pest of horticultural crops endemic to South and Southeast Asia. Methyl eugenol (ME), a naturally occurring phenylpropanoid, is a male attractant used to lure and (when mixed with an insecticide) annihilate the males from the wild population, a method of pest control termed the male annihilation technique (MAT). ME is reported to enhance the mating success of sterile males of Bactrocera spp., which is critical for enhancing the effectiveness of the sterile insect technique (SIT). The suppressed response of ME-treated males to ME-baited traps/devices allows the simultaneous application of the MAT and SIT, increasing the efficiency of area-wide integrated pest management (AW-IPM) programs. However, ME treatment in sterile males in SIT facilities is logistically difficult. β-caryophyllene (BCP) is a widely occurring, safer plant compound and is considered suitable for treating males in SIT facilities. Here, we demonstrate that BCP feeding enhanced B. zonata male mating success to the same extent as ME feeding. Feeding on BCP suppressed the male's subsequent attraction to ME-baited traps, but not to the same degree as feeding on ME. The results are discussed and BCP is suggested as an alternative to ME for the concurrent use of the MAT and SIT.

Potential of Fruit Extracts as Attractants of Female Oriental Fruit Flies

<b>Background and Objective:</b> The oriental fruit fly <i>Bactrocera dorsalis</i> (Hendel) is one of the most important insect pest species of fruit and vegetable crops in the tropical and subtropical regions. This study aimed to determine the attraction of female and male <i>B. dorsalis</i> fruit flies to the aroma of fruit juice from the host plants as well as their attraction to methanol extract, ethyl acetate extract and distillate water of selected host fruits. <b>Materials and Methods:</b> The attractiveness of the juice and extract/distillate water of the host fruits to <i>B. dorsalis</i> fruit flies was carried out in an experimental cage measuring 200×200×200 cm that was placed in the laboratory. The volatile compounds in the juice, methanol extract, ethyl acetate extract and distillate water of the selected fruits were analyzed using GCMS-Pyrolysis. <b>Results:</b> The results show that among the eight fruit juice aromas tested, the ones that significantly affected the number of trapped female <i>B. dorsalis</i> were the aromas of banana juice, papaya juice and chilli juice. The results of the analysis by GCMS-Pyrolysis showed that the methanol extract of banana fruit contains one volatile compound that was previously reported to have the ability to attract female <i>B. dorsalis</i> fruit flies. Two volatile compounds in the banana distillate water were also reported to have the ability to attract female <i>B. dorsalis</i> and other fruit flies. <b>Conclusion:</b> From the results of this study, it can be concluded that the methanol extract and distillate water of the green <i>Ambon lumut</i> banana fruit of <i>Musa acuminata</i> Colla has the potential to be developed as an attractant of female <i>B. dorsalis</i>.

Epicuticular chemistry reinforces the new taxonomic classification of the Bactrocera dorsalis species complex (Diptera: Tephritidae, Dacinae)

Bactrocera invadens Drew, Tsuruta & White, Bactrocera papayae Drew & Hancock, and Bactrocera philippinensis Drew & Hancock, key pest species within the Bactrocera dorsalis species complex, have been recently synonymized under the name Bactrocera dorsalis (Hendel). The closely related Bactrocera carambolae Drew & Hancock remains as a discrete taxonomic entity. Although the synonymizations have been accepted by most researchers, debate about the species limits remains. Because of the economic importance of this group of taxa, any new information available to support or deny the synonymizations is valuable. We investigated the chemical epicuticle composition of males and females of B. dorsalis, B. invadens, B. papayae, B. philippinensis, and B. carambolae by means of one- and two-dimensional gas chromatography-mass spectrometry, followed by multiple factor analyses and principal component analysis. Clear segregation of complex cuticule profiles of both B. carambolae sexes from B. dorsalis (Hendel) was observed. In addition to cuticular hydrocarbons, abundant complex mixtures of sex-specific oxygenated lipids (three fatty acids and 22 fatty acid esters) with so far unknown function were identified in epicuticle extracts from females of all species. The data obtained supports both taxonomic synonymization of B. invadens, B. papayae, and B. philippinensis with B. dorsalis, as well as the exclusion of B. carambolae from B. dorsalis.