Population Dynamics and Visit Timing of Insect Pollinator Families In Canola (Brassica Napus L.) Crops in Peshawar

Abstract

This study was carried out in the Newly Developmental Farm (NDF) of the University of Agriculture, Peshawar, during 2019-20. Its purpose was to determine the population dynamics, visit timing, and activity patterns of insect pollinators of canola crop. The order recorded such as Diptera, Hymenoptera, Lepidoptera, and Coleoptera. Diptera was the most abundant, with eight species in the family. The Syrphidae family had seven hoverfly species recorded. The Hymenoptera order had Apidae with four species of bees. The findings of the study indicated that the most active and consistent pollinators throughout the study period were European honeybees (Apis mellifera) and European hoverflies (Eristalis tenax), putting their very importance in the pollination of the canola crop.

The information acquired on the temporal foraging patterns of these pollinators was quite rich in weekly observations during both morning hours, that is, 10:00 AM -12:00 PM, and in the evening hours for 03:00 PM-05:00 PM. Evening sessions were by Apis mellifera while a total of 241 Syrphid flies, who recorded the most prolific evening session with a total of 201. Other notable contributors included in the study were the Marmalade hoverfly, which appeared high in population during morning periods, and the Blue Butterfly (Zizina otis) showed a peak activity in the evening. Other species, for instance, include the Common hoverfly Ischiodon scutellaris and Giant honey bee (Ischiodan scutellaris), which were characterized by stable populations, giving weight to the fact that hoverflies and bees are key pollinators of canola.

The results suggest that an adequate abundance, as well as diversity of the pollinator community, are critical for high crop productivity. The work indicates that pollinators in canola fields have specific activity patterns and complex interactions, and therefore the study emphasizes the use of conservation strategies that would protect habitats for pollinators, support more sustainable agriculture practices, and increase biodiversity in canola fields.