The International Commission of Plant Pollinator Relations:' Twelfth Symposium on Pollination

Connal Eardley ^1* Katja Hogendoorn ² Christine Coppinger ³

• ¹ North-West University, Potchefstroom, South Africa
• ² University of Adelaide, Adelaide, South Australia, Australia
• ³ University College Dublin, Dublin, County Dublin, Ireland

But this is not the whole story: consump on of floral resources by non-pollina ng species is not in the plant's interest. Therefore, in addi on to traits that a ract effec ve pollinators, plants have evolved many mechanisms to exclude ineffec ve floral visitors, or 'freeloaders'. This includes protec ng floral resources by making them difficult to access or digest, as well as a rac ng pollinators without offering a reward, e.g. by simula ng the presence of food or a mate. In response, many flower visitors and pollinators have evolved diges ve, sensory or morphological traits to overcome such defenses. Thus, flower and pollinator morphology are the outcome of pressures to improve mutualisms as well as those exerted in an arms race.In addi on, pollina on is important in the context of conserva on and food produc on. Pollinators are crucial for the survival of plant diversity, and they are involved in the produc on of 30% of our diet and play a role in reproduc on for over 75% of global agricultural crops.Considering these mul faceted aspects of pollina on, as well as complex evolu onary interac ons, it is not surprising that the symposium covered a wide range of topics. Understandably pollinator-plant interac ons were topical through nearly all sessions. Ten talks focused on more floral adver sement, and predominantly considered dynamics in colour, structure, scent and flowering me. Those with an emphasis on pollinators were more case study oriented or inves gated pollen dispersal and pollina on syndromes. Adap ve evolu onary change in floral cues because of pollinator shi s, the most frequently invoked drivers of floral divergence, was a recurring subject of many talks. Such shi s can be the result of geographic migra on of plants, changes in land use or climate, pollu on or pes cide use.In crop pollina on, apple, blueberry, pigeon pea, co on, corn, soy and avocado were specifically considered, and research included solitary bees, honeybees, and bumblebees. For the la er taxa, which are the most important managed pollinators, health risks posed by pes cides, and protocols to test for health assessment were presented in detail, as well as the ICPPR Bee Protec on Group involvement therein.The importance of the maintenance of pollinator biodiversity in pollina on dependent crops was repeatedly expressed during the crop pollina on sessions well as in the presenta ons addressing climate change and land use. Main strategies to achieve this included maintaining and protec ng areas of natural vegeta on. However, the cul va on of pollinator friendly plants and of trapnests can help as well. It was noted that future research could consider flower morphology when developing new cul vars of blueberry and use genomic informa on to breed a rac ve lines.Presenta ons on a variety of topics expressed the need for ongoing monitoring of pollinators. The approaches included involving ci zen scien sts, camera monitoring, pan traps and trap nests. Of par cular note were techniques and tools for studying orchid pollina on risk assessment. Documenta on of pollinator diversity requires taxonomists -an increasingly rare breed. On-line tools and educated ci zen scien sts can help, as well as databases of gene c or genomic informa on for reliably iden fied species. However, to allow recogni on and descrip on of new species, funding for taxonomy is s ll needed.Five of the presenters have submi ed a paper based on their oral presenta on to this special edi on. True to the symposium, they cover a range of issues.Three of these papers inves gate how different groups of bees can be supported. This is of par cular importance in the face of habitat loss and effects of extreme weather influences on floral resource availability. Two of these papers focus on the maintenance of crop pollinators, and the third inves gates the maintenance of wild bees. Sultana et al. inves gate effects of various cheap supplementary feeding mixtures on honey bee colony maintenance and growth during dearth condi ons. Escobedo-Kenific et al. find that forest reserves help in maintaining pollinator diversity and pollina on services in tropical agricultural highlands. Finally, Krahner et al. analyse whether mulched wild flower strips in fallow vineyards have the poten al to increase the species richness and abundance of wild bee species.Another two papers inves gate the effects of land use and plant diversity, and composi on on the presence and seasonality of bees in urban and agricultural ecosystems. Floral species composi on, size, shape and loca on of habitat patches affected pollinator diversity in urban areas (Walker). However, Casiá-Ajché et al.'s study of bees in coffee planta ons shows that the type of habitat, such as forest, grassland, or homestead habitats, affected pollinator species composi on and diversity in agroecological regions.