Diversity and foraging activity of pollinators of Foeniculum vulgare Miller in Bikaner, India

Abstract

Fennel, a popular winter rabi spice, relies heavily on pollinators for its reproduction. Periodical surveys conducted in fennel fields at weekly intervals, revealed 31 species of flower visitors/pollinators which included 31 insect species from 17 families and 6 orders with Dipterans and Hymenopterans being the most dominant visitors. Hymenoptera (58.21%) was the most common insect order to visit the fennel flowers in terms of percent abundance. Apis florea (19.86%), Lucilia sericata (17.73%) and Polistes olivaceus (17.73%) were identified as the most frequent pollinators. The highest foraging activity was observed at 11:00 a.m (15.09 bees/10 plants/ 5 minutes). The foraging behaviour of these pollinators varied significantly with Apis florea spending the maximum time per flower (75 sec). A. florea (21.24) and L. sericata (23.41) had the highest foraging rates. The study revealed that the foraging activity of these pollinators was significantly correlated with weather parameters. A. florea exhibited a substantial negative correlation with relative humidity  (r=-0.7224) and a significant positive correlation with both maximum and minimum temperatures (r=0.8100 and 0.7523, respectively). A. florea and L. sericata were found to be more sensitive to temperature change, resulting in more dramatic changes in foraging behaviour with warming.