| Sumario: | Background: The success of sterile insect technique (SIT) programs against many tephritid
fruit flies, including Ceratitis capitata (Wiedemann), relies on the mating success of released
sterile males in the field. Since its´ development in an area-wide concept, this control program
is evaluated by the recapture ratio of sterile versus wild flies. This measure neither takes into
account the real target of the SIT that is the wild female, nor does it give any clue about the
success of released sterile males. Thus, the contribution of released sterile males to reduce the
wild population still remains as a key issue. In this work we review recent findings on how
sterile males contribute to reduce wild populations by means of analyzing the sperm content
of wild females, as the real target of the SIT program.
Methods: A mating competition test was initially performed in laboratory and then under
semi-natural conditions, with different Ceratitis capitata Vienna-8 tsl release ratios. The
efficacy of the SIT and its contribution to reduce wild population was assessed by
determining the percentage of females mated with sterile male, with a sperm ID molecular
test, and by linking to offspring production on sentinel hosts.
Results: Statistical methods have been developed with the obtained data of sperm ID in the
spermathecae of captured females and with data of viable offspring produced in sentinel
fruits, revealing that both can be predicted using release ratio and mean temperature.
Moreover, humidity arose also as a factor influencing the female capture in lured traps. A
strong negative relationship was established between the proportion of Vienna-8 mated
females and Ceratitis capitata offspring production, being a key point for a model to predict
the SIT program success.
Conclusions: The statistical models developed should contribute to enhance the efficacy of
SIT programs against Ceratitis capitata by means of modulation of release ratios by season
temperature and by checking wild female’s sterile sperm content.
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