Columnar cacti can be pollinated by various insect and vertebrate species, often showing either close adaptations to a single pollinator group, or a mixed pollination syndrome, depending on a variety of different animals for pollination. As pollination data for columnar cacti in South America are scarce, we investigated the spectrum, frequency, and behavior of floral visitors in Echinopsis atacamensis subsp. pasacana. We compared two habitats with differences in mean annual precipitation and human impact, finding considerably higher activity and diversity of flower visitors in the population with higher humidity. Bees, wasps, and the giant hummingbird (Patagona gigas) were shown to visit cactus flowers during the day to gather nectar or pollen. We found marked differences in the spectrum of floral visitors between both populations. In one study site, the introduced honeybee Apis mellifera removed large quantities of pollen, but seemed to be a comparatively inefficient pollinator. Additionally, first evidence for visits by nocturnal hawkmoths is provided. These results demonstrate an unspecialized floral syndrome for Echinopsis atacamensis subsp. pasacana, with both diurnal and nocturnal pollinators. Such a mixed floral syndrome is fairly widespread among columnar cacti in the northern hemisphere but was hitherto only shown for one South American species, Weberbauerocereus weberbaueri.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.