DYNAMICS OF THE ADAPTATION OF A WILD POPULATION OF ANASTREPHAFRATERCULUS (DIPTERA: TEPHRITIDAE) TO LABORATORY CONDITIONS.

PARREÑO, MARÍA ALEJANDRA; JURI, MARIANELA; CONTE, CLAUDIA ; LIENDO, MARÍA CLARA; MILLA, FABIÁN H.; GARCÍA ALBA, M; SEGURA, DIEGO F. ; CLADERA, JORGE L; VERA, MARÍA TERESA; LANZAVECCHIA, SILVIA B.

Ciudad de Panamá

Congreso; 8th Meeting of the Working Group on Fruit Flies of the Western Hemisphere; 2012

Anastrepha fraterculus Wied. (Diptera: Tephritidae) is a fruit fly pest native to South America. Modern insect pest control methods such as the Sterile Insect Technique and the use of natural enemies are based on the release of mass reared insects. Therefore, studies on the genetic and biological processes that take place in laboratory conditions and subsequently up-scaling to mass-rearing procedures are required in order to carry out these programs successfully. In the present study, individuals collected from a wild population (named TW) were used to establish five colonies which were reared under laboratory conditions for 6 generations. At the same time, five colonies where initiated with an already established laboratory strain (named CL) with more than 100 generations under artificial rearing. Every generation we recorded length of oviposition period, fertility (percent of egg hatch), percent of adults recovered from pupae, sex ratio and adult mortality. Additionally, at G0, G3 and G5, we evaluated, pupal weight and we performed a male mating performance test by the exposure of virgin CL and TW females to males from both strains. TW and CL showed differences in every parameter measured, with the exception of sex ratio. These results would suggest that after a critical initial bottleneck effect due to the adaptation to new environmental conditions, selected specimens increase the population quality parameters after G3. The mating performance test showed that at G0 females from both lines (TW and CL) preferred the adapted CL males for mating. This may be due to the stress to which the individuals are subject when recently introduced to the new environment. However, G5 CL females showed no discrimination between CL and TW males and G5 TW females preferred TW males. This suggests that females from recently adapted strains can still discriminate between males coming from a recently adapted strain and a strain that has been reared for >100 generations. Apparently, this ability is lost in laboratory females. The results presented here contribute to a better understanding of the adaptation processes of A. fraterculus to artificial rearing conditions. In order to identify the factors involved in the genetic process underlying, additional studies using microsatellite markers are in progress.