Beneficial aspects of insects
•Pollination:
Flowers pollinated by insects are called entomophillous.
Entomophilous flowers are usually brightly colord, produce nectar and have an odor that will attract insects
Insect that visit flowers do so for two different food sources, the sugary nectar and protienaceous pollen .
•They live in mutualistic relationship with the plants, the plants are their only source of food.
•The flowers produce the nectar and scent purely to attract the pollinating insects and they usually produce a considerable excess of pollen to allow for that taken as insect food.
•Nectar is required by most bees early in the season (spring) after the winter hibernation as a source of energy.
Some pollen-seeking insects may open the anther sacs and are beneficial in causing more effective pollen release., e.g, pollen beetles (Meligethes spp) on rape.
•It was known that insecticides are harmful to bees, although some 20 years ago it was thought that some were harmless.
•In 1950-1970 most bees damaged due to use of new organochlorine compounds.
•Drastic decline in pollination were not appreciated in Japan 25 % of labour time was spent on hand pollination.
•Although there has been great effort made in the field of assisted pollination.
•In Japan small colonies of osmia cornifrons were installed in apple orchards in artificial nest sites constructed from a small bundle of plastic tubes. Now it came to USA.
•In UK bumble bees has been reared for pollination in green house. E.g., Tomatoes
0 Comments:
Post a Comment