SCIENTISTS are calling attention to a grave threat that faces plant breeding - the declining number of pollinators like insects, bees, moths, bats, flies and birds. These organisms do a world of good to most plants in land-based eco- systems, by helping ,them reproduce by means of pollination. And when the whole system of plant propagation is in jeopardy, the prospect of losing rare species or even whole bits of nature becomes a frightening reality ( The Amicus Jouma~ Voll8, No 1)
A recent experiment involving the cereus cactus plant -which blooms once in a year -had volunteers waiting in vain at Sonoran desert near the us- Mexico border, for the sphinx moths to appear, suck the nectar and pollinate the cereus. This would have ensured another season of fruit. Gary Nabhan, science director of the Arizona-Sonora Desert Museum, and leader of the nightlong cereus vigil, has along with his colleagues including Stephen Buchmann, an entomologist at the University of Arizona, gathered a lot of evidence which indicates that local pollination, specifically in the Sonoran eco-system, is in deep trouble.
The reasons for the decrease in numbers of pollinators are many. Heading the list, however, is the ram- pant use of pesticides. These chemicals do not discriminate between agricultural pests and useful pollinators. The bee, for instance, has been widely hit by the continuous use of pesticides. The residues often store in beehives, and affect the queen bee's ability to lay the requisite number of eggs.
Farmers also blame the disruption of habitats of useful insects as another reason. Frequented sites of the pollinators have been lost to the cause of farming, logging or overgrazing, Pollination of flowers is thus affected which subsequently results in the lessening of plants. Flowers thereby bloom in vain and in the words of Nabhan and Buchmann, forests may one day face a "fruitless fall".