Developmental plasticity, the ability of a single genotype to express different phenotypes in different environments, may evolve as an adaptive response to seasonality and is typically characterized by reaction norms. Temperature, one of the most important and common environmental factors regulating development is of extreme importance in regulating seasonal plasticity of insect´s pigmentation patterns, namely in butterflies. Here, we would like to explore the genotype (G), temperature (T), and GxT effects on Bicyclus anynana pigmentation patterns. B. anynana butterflies exhibit developmental plasticity for pigmentation patterns as an adaptive response to the alternating wet and dry seasons in their natural environment. In addition, this system also shows developmental plasticity for life-history traits. In order to explore GxT effects on B. anynana pigmentation patterns we derived artificial selected lines expressing extreme wet season-like or dry-season-like phenotypes at intermediate temperatures and characterized thermal reaction norms for several traits for a wide range of temperatures. Finally, for the first time in this species, we performed qualitative analysis of color and color patterns across temperature. Our preliminary results show that, for both sexes, there is a significant GxT interaction which confirms mean differences between the unselected stock and artificial selected lines responses in shape and height of reaction norms across temperature. Future directions include developing a detailed formal mathematical treatment of the influence of external environment on development to characterize shape of thermal reaction norms. Curiously by selecting on extreme pigmentation patterns we were able to change other traits such as survivorship and pupal development time. These correlated responses to selection likely reflect genetic pleiotropy. We also show, for wing background color, that for low temperatures there are three groups of pigments and for high temperatures four well distinct groups. Our preliminary results also revealed a possible new color appearing at the most extreme low temperatures. We do not know what causes these differences, but we suggested that the orange color might correspond to a pigment from a different type or to a modification of a product of the melanin biosynthesis pathway. Our future work includes developing a general method to quantify color patterns possible to apply to most of the organisms.

Date Submitted: 2016-04-27