## 6 Tephritid Sexual Chemoecology: Real-World Applications and Challenges
### Eradication and Suppression of Fruit Fly Populations Employing Semiconchelicals  
Male lures such as trimedlure and especially methyl-eugenol (ME), besides being employed for population monitoring, have been used for more direct control purposes. Male annihilation technique (MAT) (i.e., elimination of males, mating and oviposition of fertile eggs, based on strong male-specific lures that are deployed in a mass trapping or lure and kill approach) is considered as a very successful option to eliminate low populations of _B. dorsalis_ and a tool that may drive invaded population to extirpation or even eradication. For example, male annihilation against _B. dorsalis_ has been used as a main tool in attempts to eradicate incursions or isolated established populations in California, Hawaii and Florida [474; 475; 476; 477; 478], South Africa [479; 480], the Marianas Islands in Micronesia [481], the Okinawa Islands in Japan [482], and Mauritius [483]. Eradication efforts using the male attractant CL against other _Bactrocera_ species such as _B. franentfeldi_ were not successful [484]. Male attraction to CL remained consistent until advanced age in _B. tryoni_, although it sharply declined after 12 weeks of age, with potential implications for pest management [485]. Despite its broad use as a population monitoring tool, trimedlure is not considered as an eradication tool against medfly. Male lures and the MAT have been considered in suppression programs often in combination with other methods and preferably in the frame of an Area Wide application strategy. As it was demonstrated in Hawaii, combination of MAT with field sanitation, protein bait, sterile male releases and biological control resulted in satisfactory reduction of the fruit fly population [486]. Methyl eugenol and CL for _Bactrocera_ species, as well as trimedlure for the medfly, have been considered. Interestingly, the use of ME for the suppression of _B. dorsalis_ in Southern Ethiopia proved to be successful [487]. The use of the female pheromone alone or in combination with other baits has been evaluated for the control of the olive fruit fly [488; 489]. These efforts include a male annihilation component but also tools against females. Apparently, classical mating disruption approaches involving saturation of target area with species-specific pheromones are not effective against fruit flies, and the MAT is prevailing. Indeed, mating disruption approaches against _B. olea_ in Spain and Greece led to inconclusive results [490; 491]. However, a more recent study, in which authors observed a decrease in fly catches in the presence of high pheromone (i.e., 1,7-dioxaspiro[5.5]undecane) concentrations, supports the applicability of a mating disruption approach against this species [492]. For the medfly, for both trimedlure and the iodinated trimedlure analogue Ceralure, no mating disruption effects have been so far described [492]. Such an absence of disruption effect in this species was explained by the lack of saturation in response to higher trimedlure concentrations [492]. Alternative strategies aimed at interfering with mating deserve to be explored, including the potential applications of CHs as disruptors. CHs are known to play a role in the mating behaviour of different _Drosophila_ species [493; 494; 495]. In _D. suzukii_, alteration of C23 alkanes ratios results in disrupting mate recognition and, as a consequence, courtship and mating behaviour [496]. The identification of OBP candidates potentially able to transport the _B. dorsalis_ female-biased CH 4-DMP [425; 426] is a promising step in the clarification of the functional role of CHs in the mating behaviour of fruit flies. Moreover, in order to improve the efficacy of any semiochemical-based approach for fruit fly eradication and suppression, additional studies should be devoted to better understand the role of abiotic factors on trapping.