Investigação de correlação entre frequência de batimento e tamanho alar de Aedes aegypti (Linnaeus, 1976)

Abstract

Differences in the ecological role within populations can generate morphological variations triggered by selective pressures that act differently in each sex, thus causing possible variations that may indicate sexual dimorphism in wing size, as well as wing beat frequency. Knowing this, the objective of the present study was to investigate whether there is a correlation between the variables of beat frequency and wing size in Aedes aegypti. For this purpose, mosquitoes with 4 to 5 days of emergence were used, placed individually in collectors, and arranged in incubators, maintaining the environmental conditions of 26°C, 60-75% RH and photoperiod of 14:10h (L:D), separated by sex. In order to obtain individuals of different sizes (large and small females and males), experimental colony was divided into two larval densities: low (50 larvae/breeding place), which generated large mosquitoes, and high (200 larvae/breeding place), which generated the small mosquitoes. After collecting alar beat frequency data, individuals were stored in microtubes containing 70% alcohol. Then, the wings were detached, mounted, photographed and digitized and centroid size analyzes were performed. Finally, correlation analyzes (Pearson) were developed. As a result, in this work, it can be confirmed that there is sexual dimorphism of the wingbeat frequency in Ae. aegypti, demonstrated by the mean frequency (large females = 531.4 x large males = 767 Hz; small females = 537.7 x small males = 721.3 Hz). Furthermore, a small difference was also observed between the frequency of wingbeats within the same sex, with smaller individuals (females and small males) having higher and lower wingbeat frequencies, respectively, when compared to larger individuals (females and males). Wing size sexual dimorphism can also be confirmed in Ae. aegypti, as well as variation within the same sex, depending on the population density applied during rearing under laboratory conditions, with large females and males having a significantly larger wing centroid than small females and males. Finally, the correlations between the beat frequency and wing size variables performed in this study showed us that large females and small males of Ae. aegypti have no correlation between wingbeat frequency and wing size. While small females showed a significant but low and negative correlation; and large males showed a significant but low and positive correlation, that is, the larger the wing size (and consequently their body), the lower their wing beat frequency.