Nectar robbers use a hole made in the perianth to extract nectar. Since robbers may modify plant fi tness, they play an important role by driving evolution on fl oral traits, shaping population structure and infl uencing community dynamics. Although nectar robbing is widespread in angiosperms, the causes and ecological implications of this behaviour on large ecological scales are still unexplored. Our aim is to study the frequency of nectar robbing in plants of temperate and tropical regions and examine its association with plant traits. We characterised the levels of nectar robbing in 88 species of Mediterranean, Alpine, Antillean and Andean plant communities and identifi ed the most important nectar robbers. We analysed associations between the levels of robbing and fl oral morphology, production and density of energy rewards, mechanisms of protection against nectar robbers, plant life form and geographic origin. Nectar robbing was present at all sampling sites. Within communities two patterns of robbing levels related to the diversity and specialization of robbers were detected. In most communities one plant species presented very high levels of robbing while other species had intermediate to low robbing levels. Th ere, nectar robbers are opportunists, robbing highly rewarding plants. In the Andean community the high specialization of several co-existing fl owerpiercers produced an even pattern of robbing levels in the plant community. Plants with long fl owers, abundant nectar and a high energy density are more likely to be robbed by both insects and birds. A high aggregation of the fl owers within the plants and the presence of long calyxes and bracts are associated to low robbing rates by insects and to a lesser extent by birds. Besides the morphological constraints that operate on a single fl ower basis, nectar robbing is a phenomenon dependent upon the density of energy rewards refl ecting the presence of mechanisms on higher ecological scales.

The efficiency and selectiveness of baited traps to control the invasive hornet Vespa velutina is often questioned. Comparative assessments are needed to improve control plans and reduce the impact on honeybees and entomofauna. Our aims were to study the performance of traps and baits, to identify environmental conditions that affect capture rates and to identify the groups of insects affected by trapping. During spring in 2016, three types of trap and baits in a full factorial design were tested. Vespa velutina accounted for less than 1% of all captures, reflecting the low selectiveness of the method. The trap design and its location are decisive aspects to determine the capture rates of V. velutina queens. All trap-bait combinations captured a very high quantity of dipterans, native hymenopterans, and lepidopterans. High capture rates of insect groups which are not common prey of V. velutina reflect that the method constitutes an additional threat on native insects. apiculture / Apis mellifera / invasive species / pest management tools / yellow-legged hornet

Although L. etrusca exhibits high levels of nectar robbing and nectar robbers are common floral visitors, no evidence was found of detrimental changes in the components of reproductive success. A combination of morphological and ecological mechanisms is proposed to explain how plants may compensate for the energetic loss caused by the nectar robbers.

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