One for all: Mating compatibility among various populations of olive fruit fly (Diptera: Tephritidae) for application of the sterile insect technique

Abstract

The olive fruit fly, Bactrocera oleae (Rossi), is the most important insect pest for the cultivation of olives worldwide. Considerable research efforts have been invested in the past decades to develop eradication or suppression tactics for use within an area-wide integrated pest management (AW-IPM) approach that includes a sterile insect technique (SIT) component. One of the major obstacles encountered in the development of SIT for olive fruit fly was the inferior quality of the mass-reared flies, expressed among others evident primarily by sterile males having a different timing of peak mating and a lower mating propensity in comparison with their wild counterparts. In this study we assessed the mating behaviour and mating compatibility of olive fruit flies originating from four countries of the Mediterranean region (Croatia, France, Italy, Spain) in walk-in field cages and post zygotic compatibility (expressed as % egg hatch) under laboratory conditions. Furthermore, we tested the hypothesis whether a hybrid strain (Greece (domesticated)/Israel (wild)) adapted to laboratory rearing conditions showed any mating barriers with all the four “wild” populations. Finally, we examined the effect of colonization on the mating compatibility of the four newly established populations over three consecutive generations. The results showed no pre-zygotic (mating barriers) or post-zygotic isolations (measured by egg hatch%) among the olive fruit fly populations from the four countries tested. Also, there was no evidence of mating barriers between the hybrid strain and the wild populations of the Mediterranean region.

Mating Competition between Wild and Artificially Reared Olive Fruit Flies

“…This is in accordance with earlier studies which indicated that massreared tephritid males tend to begin calling and mating earlier in the day than the wild population [28,29]. Mating latency is considered critical for the success of the SIT/RIDL, as earlier matings of wild males would potentially leave fewer opportunities for sterile males to transfer their sterile sperm to the wild females [11]. Additional bioassays in larger field cages and under natural light conditions are required to further explore differences in mating latency between AR and W flies.…”

“…Studies on the mating behavior of olive fruit flies have indicated that colonization and rearing under laboratory conditions for many generations have a negative effect on male fitness and mating behavior [9,10]. Generally, long-term rearing under artificial conditions negatively affects behavioral and physiological aspects of insects [11], in addition to their longevity [12].…”

The Insect Pest Control Laboratory of the Joint FAO/IAEA Programme: Ten Years (2010–2020) of Research and Development, Achievements and Challenges in Support of the Sterile Insect Technique

“…Assessing tsetse mating behavior under field conditions is challenging and expensive, and the results can be influenced by several environmental, climatic and ecological parameters which cannot be controlled. Walk-in field cages have been utilized successfully as a surrogate for field studies to conduct mating compatibility, mating competitiveness and other behavioral studies with fruit flies [ 104 ], lepidoptera [ 105 ], mosquitos [ 106 ] and tsetse flies [ 89 ].…”

Symbiosis in Sustainable Agriculture: Can Olive Fruit Fly Bacterial Microbiome Be Useful in Pest Management?

“…Non-insecticidal alternatives that have worked in some situations or shown potential include (a) mass trapping programs [84,85,86], (b) sterile insect technique (SIT) [87,88,89], (c) particle film [90,91,92] and (d) biological control using natural enemies [66]. Symbiosis-based strategies are still under developed, albeit attempts with the use of copper products as symbionticides [92,93,94].…”