ИСТИНА

During several years (2004-2009) we investigated patterns of insect behavior which can influence pollen flow in insect-pollinated plants. Our main result is revealing of the influence of local plant density on pollinator set. Most insect species prefer visit denser plant patches but some others - vice verse. Such differences occur even in very close patches divided by several meters. Even denser center and sparser periphery of one distinct patch face very different pollinator sets. It doesn’t bring about pollen limitation (even in obligately cross-pollinated Umbelliferae). But these findings mean that the pool of pollen which can participate in pollination of different individual of the same species depends on local density of the patch in which it grows. Within one patch most of pollinators fly non-randomly: they visit flowers (or inflorescences) within small area (usually near 4 mean distances between these object in the patch) and then move to another such area. So pollen flow within plant populations is greatly restricted by these areas. But beetles and social bees can be good vectors of long-distance pollen flow. First – because of movement patterns differing from other insects – very high frequency of long flights between successive visits. Social bees despite of little mean flight distance and low frequency of long flights can transport pollen to the great distances mostly because of high pollen load. Butterflies have large mean flight distance and rate of moving away but because of very little pollen load aren’t good long-distance pollen vectors. Diptera are also bad pollen vectors because of small pollen loads and liow rate of moving away (though Syrphidae possibly are better than Muscoid flies in long-distance pollination).