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Insect flight is a complex trait involved in different behaviors, from the search for sexual partners, food, or breeding sites. Many studies have postulated the adaptive advantages of certain morphological traits in relation to increased flight capacity, such as low values of wing loading or high values of wing:thorax ratio and wing-aspect ratio. However, few studies have evaluated the relationship between variables related to flight and morphological traits in Drosophila. This work aimed to study morphological traits in males and females of two pairs of sibling species: Drosophila buzzatii Patterson and Wheeler-Drosophila koeferae Fontdevila and Wasserman, and Drosophila melanogaster Meigen-Drosophila simulans Sturtevant, and to analyze its relationship with flight. We detected the highest proportion of flight time in D. koepferae and D. simulans compared to D. buzzatii and D. melanogaster, respectively. Our results also revealed sexual dimorphism, with males exhibiting a higher proportion of flight time than females. Surprisingly, we did not find a general pattern to explain the relationship between morphology and the proportion of flight time because associations varied depending upon the analyses (considering all groups together or each sex-species combination separately). Moreover, these associations explained a low percentage of variation, suggesting that other nonmorphological components related to flight, such as physiological variables, should be taken into account. This work allowed us to show the variability and complexity of an aspect of flight, suggesting that the adaptive role of the morphological traits studied might have been overestimated., (© 2023 Institute of Zoology, Chinese Academy of Sciences.)

It has been demonstrated that phenotypic plasticity and genotype by environment interaction are important for coping with new and heterogeneous environments during invasions. Zaprionus indianus Gupta (Diptera: Drosophilidae) is an Afrotropical invasive fly species introduced to the South American continent in 1999. This species is generalist and polyphagous, since it develops and feeds in several different fruit species. These characteristics of Z. indianus suggest that phenotypic plasticity and genotype by environment interaction may be important in this species invasion process. In this sense, our aim was to investigate the role of genetic variation for phenotypic plasticity (genotype by environment interaction) in Z. indianus invasion of the South American continent. Specifically, we quantified quantitative genetic variation and genotype by environment interactions of morphological and life history traits in different developmental environments, that is, host fruits. This was done in different populations in the invasive range of Z. indianus in Argentina. Results showed that Z. indianus populations have considerable amounts of quantitative genetic variation. Also, genotype by environment interactions was detected for the different traits analyzed in response to the different developmental environments. Interestingly, the amounts and patterns of these parameters differed between populations. We interpreted these results as the existence of differences in evolutionary potential between populations that have an important role in the short- and long-term success of the Z. indianus invasion process., (© 2019 Institute of Zoology, Chinese Academy of Sciences.)

Changes in the environmental conditions experienced by naturally occurring populations are frequently accompanied by changes in adaptive traits allowing the organism to cope with environmental unpredictability. Phenotypic plasticity is a major aspect of adaptation and it has been involved in population dynamics of interacting species. In this study, phenotypic plasticity (i.e., environmental sensitivity) of morphological adaptive traits were analyzed in the cactophilic species Drosophila buzzatii and Drosophila koepferae (Diptera: Drosophilidae) considering the effect of crowding conditions (low and high density), type of competition (intraspecific and interspecific competition) and cacti hosts (Opuntia and Columnar cacti). All traits (wing length, wing width, thorax length, wing loading and wing aspect) showed significant variation for each environmental factor considered in both Drosophila species. The phenotypic plasticity pattern observed for each trait was different within and between these cactophilic Drosophila species depending on the environmental factor analyzed suggesting that body size-related traits respond almost independently to environmental heterogeneity. The effects of ecological factors analyzed in this study are discussed in order to elucidate the causal factors investigated (type of competition, crowding conditions and alternative host) affecting the election of the breeding site and/or the range of distribution of these cactophilic species., (© 2016 Institute of Zoology, Chinese Academy of Sciences.)