Diversity and foraging behavior assessment of watermelon pollinators in Tizi-Ouzou area (Algeria)

Abstract

Foraging insects of watermelon, Citrullus lanatus (Cucurbitaceae), were studied during flowering periods in 2016 and 2017 in Tizi-Ouzou area (Algeria). Our observations showed that a majority of watermelon visitors were apoid Hymenoptera belonging to three families. Eleven species were identified including six Apidae, four Halictidae and one Megachilidae. Apis mellifera was the most abundant species on watermelon flowers followed by Lasioglossum pauxillum and Ceratina saundersi. The daily activity study of these species demonstrated varying patterns of daily distribution. During two flowering periods, the greatest bee activity occurred in the morning recording peak visits between 8 am and 9 am and was synchronized with the maximum flowers opening. The behavioral study of these species did not reveal the pollen collection but all the visits were devoted to nectar collection. Regarding pollinating efficiency of these three species, results showed that honey bee was the fastest recording a foraging speed of 9.9 ± 1.25 flowers/min and the three species spent significantly more time on female flowers than male flowers. This work highlighted the mutual relationship between watermelons and bees. Firstly, this plant provides the nutritional needs of these insects during the drought period and secondly, the bees guarantee Cucurbitaceae pollination.