Nectar Physiology of Plants - A Basis to Study on Co-evolutionary Relationship with their Butterfly Pollinators

The efficacy of co-evolution in determining the relationships between plants with food-rewarding flowers and their pollinators is more controversial. If co-evolution was an important process in the plant-butterfly interaction system, the plants might have been expected to evolve so as to preferentially attract butterflies and discourage visits of other insects and/or to evolve morphological characteristics promoting the effectiveness of butterflies in transferring pollen. Thus, the present study aims to reveal the co-evolutionary relationship of four butterfly-pollinated flowers Cadaba fruticosa (L.) Druce, Caesalpinia pulcherrima (L.) Sw., Clerodendrum infortunatum L. and Clerodendrum phlomidis L.f. Though the nectar features and pollination biology have occurred independently in different lines, their convergence is the result of the sugar intake efficiency of specific pollinators, their digestive abilities and plant adaptation to preferences. So, the nectar characteristics of these flowers are studied and found a good correlation with butterfly-preferred nectars. The two Colotis species oviposit on the leaves and flower buds and the larvae feed on the same. Therefore, the occurrence of co-evolution can be imagined in this Cadaba – Colotis system. The study revealed that the floral morphology of the four plants Cadaba fruticosa, Ceaslpinia pulcherrima, Clerodendrum phlomidis, and Clerodendrum infortunatum appears highly labile and contrasts with the great similarity of sugar composition and concentration measured in the butterfly flowers led to the conclusion for existence of the co-evolutionary relationship with their butterfly pollinators.