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Ants on flowers can disrupt pollination by consuming rewards or harassing pollinators, but it is difficult to disentangle the effects of these exploitative and interference forms of competition on pollinator behavior. Using highly rewarding and quickly replenishing artificial flowers that simulate male or female function, we allowed bumblebees (Bombus impatiens) to forage (1) on flowers with or without ants (Myrmica rubra) and (2) on flowers with or without ant scent cues. Bumblebees transferred significantly more pollen analogue both to and from ant-free flowers, demonstrating that interference competition with ants is sufficient to modify pollinator foraging behavior. Bees also removed significantly less pollen analogue from ant-scented flowers than from controls, making this the first study to show that bees can use ant scent to avoid harassment at flowers. Ant effects on pollinator behavior, possibly in addition to their effects on pollen viability, may contribute to the evolution of floral traits minimizing ant visitation.

BACKGROUND Many studies have evaluated radiofrequency microneedling (RFMN) in various dermatologic conditions. However, the efficacy and safety of RFMN, and how it compares with other energy-based devices in a clinician's armamentarium, remains unclear. OBJECTIVE To review higher-quality evidence supporting RFMN and the dermatologic conditions which it can be used in. MATERIALS AND METHODS A search was conducted in MEDLINE and EMBASE from inception to May 13, 2020, using the terms: “radiofrequency microneedling” OR “fractional radiofrequency” OR “radiofrequency needling” OR “radiofrequency percutaneous collagen induction.” Only randomized, split body or blinded studies with original data on humans were included. Non-English or non–dermatology-related studies were excluded. RESULTS Forty-two higher-quality studies were included after applying the inclusion and exclusion criteria. There were 14 studies for skin rejuvenation, 7 for acne scars, 6 for acne vulgaris, 5 each for striae and axillary hyperhidrosis, 2 for melasma, and 1 each for rosacea, cellulite, and androgenetic alopecia. CONCLUSION Radiofrequency microneedling is an effective intervention that can be used repeatedly and safely in combination with other treatment modalities and in individuals with darker skin phototypes. Radiofrequency microneedling–induced dermal remodeling and neocollagenesis are slow and progressive but continue to improve even 6 months after treatment.

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