Oviposition behavior of females of Anastrepha fraterculus and Ceratitis capitata (Wiedemann) in infested fruit

M. CLARA LIENDO; FABIÁN H. MILLA; M. ALEJANDRA PARREÑO; M. TERESA VERA; JORGE L. CLADERA; DIEGO F. SEGURA

Congreso; 9th International Symposium on Fruit Flies of Economic Importance; 2014

Background: A. fraterculus and C. capitata are two important fruit pests in Argentina. These species can be found overlapping their area of distribution and host fruits. This can lead to the development of mechanisms that allow them to escape competition. The use of host marking pheromones (HMPs) is an example of these mechanisms and both species present this behavior. The aim of this work was to study the importance of chemical signals coming from infested fruit on the female host choice. Method: We placed two options of plum in a experimental arena. We released one wild female and we registered their behavior until she left the fruit. We recorder the selected option fruit, time of permanence in the fruit, punctures performed to the fruit and duration of oviposition. The experiments performed were: 1- Intraspecific competition: the options presented to the females were uninfested fruit and a fruit infested for conspecific females; and 2- Interspecific competition: the options presented to the females were uninfested fruit and a fruit infested for heterospecific females. Result: The frecuency of visits of each option was similar, regardless of the combination of fruit offered (intraspecific competition or interspecific competition) and flies species (A. fraterculus or C. capitata). For A. fraterculus, in a intraspecific experiments, the percentage of females that did not laid their eggs were similar for both options of fruit. However, in a interspecific experiment, the rejection frecuency of fruits as substrate of oviposition was higher for infested fruit. The same result was found for C. capitata. Conclusions: For the two species, oviposition by females is deterred in fruits that are infested by individuals of the competitor species This recognition leads to the avoidance infested fruit, suggesting a mechanisms that favor the stable coexistence of these species in nature.