Morphometric Traits and Fluctuating Asymmetry as Indicators of Larval Stress in Two Tephritidae Fruit Flies.

GOANE, L.; LIENDO, M. C.; RUIZ, M. J; JUÁREZ, M. L.; VALLADARES, G.; MILLA, F.; SEGURA, D.; VERA, M. T.

Simposio; 9 rEUNIÓN DEL GRUPO DE TRABAJO MOSCAS DE LA FRUTA DEL HEMISFERIO OCCIDENTAL; 2016

Body size is largely recognized as a major fitness related trait which contributes tomale successful mating, dispersal capacity, longevity and female fecundity; standingbigger individuals as better fitted. In holometabolous insects, adult body size largelydepends on the conditions faced during larval development which is reflected in thereserves stored at pupal stage, often measured through the pupal weight. Previousstudies in two important pests, Anastrepha fraterculus and Ceratitis capitatashowed that overcrowding during larval development causes a reduction in pupalweight. Our objective was to find one adult morphometric traits which correlateswith pupal weight in order to use it for further studies about the relevance ofcompetition and larval rearing media as modulators of adult morphology. Inaddition, we examined fluctuating asymmetry (FA) of adults as a possible indicatorof stress experienced during larval development. Pupae from different weightswere obtained by manipulating egg densities. After adult emergence, we measuredhead width, thorax length, wing width, wing length, femur length and tibia lengthfrom the third leg. FA was evaluated in two bilateral traits (wings and legs) amongadults obtained from pupae with different weight. Wing length was the variablewhich correlated the highest with pupal weight, suggesting it could act as a reliableindicator of stress by overcrowding, both for A. fraterculus and C. capitata. Onthe contrary, FA of wings was not consistently affected by pupal weight, showingthat wing FA is not a good indicator of developmental instability inflicted bycompetition at the larval stage for both fruit flies species. Femur and tibia lengthwere not suitable for the analysis due to high measurement error. We discuss therelevance of this approach to understand the impact of competition and host useduring larval development on life history traits and henceforth in pest management.