Unlike most other bees, the long-tongued orchid bees ingest nectar using suction feeding. Although long tongues allow exploitation of flowers with deep spurs, the energy intake rate is optimal at 10-20% lower nectar sugar concentrations compared to that of lapping bees. This constraint might be compensated by a higher digestive throughput. Additionally, orchid bees might evaporate water from re...

A fundamental question in community ecology is how the quantity of floral resources affects pollinator activity and this relates to structure robustness pollination networks. The issue has been mainly addressed at species level, while level several questions are still open. Using a species-rich semi-natural grassland as model ecosystem, we explored relationship between community-level resources...

Floral-color Changes Floral-color changes are common among the angiosperms. At least three non-exclusive hypotheses have been proposed to explain these changes: 1. Once flowers are adequately pollinated, further pollinator visits impair reproduction by deposition of self-pollen, dislodging of pollen, or damage to floral parts. 2. Color changes mark flowers that have been depleted of their rewar...

Floral-color Changes Floral-color changes are common among the angiosperms. At least three non-exclusive hypotheses have been proposed to explain these changes: 1. Once flowers are adequately pollinated, further pollinator visits impair reproduction by deposition of self-pollen, dislodging of pollen, or damage to floral parts. 2. Color changes mark flowers that have been depleted of their rewar...

Nectar and pollen are floral resources that provide food for insect pollinators, so quantifying their supplies can help us to understand mitigate pollinator declines. However, most existing datasets of resource measurements focus on native plants found in rural landscapes, cannot be used effectively estimating urban green spaces, where non-native ornamental often predominate. We sampled nectar ...

BACKGROUND AND AIMS Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared. METHODS Naturally occurring pollen loads carried by the common floral visitor species of G. sempervirens were compared. In addition, dyed pollen donor flower...

1. Neonicotinoids are now the most widely used insecticides in the world. They act systemically, travelling through plant tissues and protecting all parts of the crop, and are widely applied as seed dressings. As neurotoxins with high toxicity to most arthropods, they provide effective pest control and have numerous uses in arable farming and horticulture. 2. However, the prophylactic use of br...

In view of the ongoing pollinator decline, the role of nutrition in bee health has received increasing attention. Bees obtain fat, carbohydrates and protein from pollen and nectar. As both excessive and deficient amounts of these macronutrients are detrimental, bees would benefit from assessing food quality to guarantee an optimal nutrient supply. While bees can detect sucrose and use it to ass...

The amount of pollen stored in honey bee, Apis mellifera, colonies is a selectable trait. Five generations of two-way selection resulted in high and low strains that differed more than six-fold in quantities of stored pollen. Comparisons with hybrid crosses suggested that colony-level, high pollen-hoarding behaviour is inherited as a recessive trait. Colony levels of stored honey, however, show...

Although anthophilous Coleoptera are regarded to be unspecialised flower-visiting insects, monkey beetles (Scarabaeidae: Hopliini) represent one of the most important groups of pollinating insects in South Africa's floristic hotspot of the Greater Cape Region. South African monkey beetles are known to feed on floral tissue; however, some species seem to specialise on pollen and/or nectar. The p...