- June 17, 2019 - Insectarium : Entomology news, Champions of nature, Roles of insects
Without pollinating insects, the landscapes all around us would be drastically different. It’s estimated that these insects take part in the reproduction of close to 80 percent of flowering plants, and that 35 percent of crops benefit from their contribution to pollination. Bees, wasps and bumblebees are the best known and most numerous, but butterflies, flies and beetles, among others, also participate in what is a colossal undertaking.
An enormous coevolution success
After they first appeared, roughly 140 million years ago, flowering plants quickly diversified, to the point where they dominated the bulk of the planet’s habitats. The development of a special relationship with pollinators is one of the reasons for that success. A number of indicators demonstrate the importance of that plant-insect relationship. The development of structures intended for pollinators, like nectaries and showily colored corollas, should be noted. Also, the appearance of flowering plants was followed by a speedy diversification of certain insect groups. Today the estimate of the number of pollinating species in the world is 200,000, of which over 99 percent would seem to be insects.
An essential contribution to our food diversity
Pollinators contribute in an important way to feeding humankind. For certain plants –most fruit trees, berries, the gourd family and canola – only the intervention of a pollinator will allow for the production of fruit and seeds. For others, like tomatoes, peppers, eggplant and green beans, self-pollination or wind pollination is possible, but the input of an insect will make for a higher fertilization rate, and therefore to improved harvests. The most important crops in terms of volume (rice, wheat, corn) tend to be wind pollinated. Nevertheless, it has been clearly documented that a marked decrease in pollination by insects would have a significant impact on our food diversity and would exacerbate the deficiencies of certain nutrients for human populations on a worldwide scale.
Besieged on several fronts
Regrettably, our world, geared as it is to growth, is less and less hospitable to these invaluable allies, which face continually multiplying threats. Insecticides, herbicides and fungicides affect reproduction, immunity and behaviors, among other matters, in numerous species of pollinators. Climate change could knock plant flowering and their life cycle out of synch. Some bumblebees are highly sensitive to episodes of extreme weather. The nutritional quality of pollen has dropped significantly since the start of the industrial age, in line with the increased proportion of CO2 in the atmosphere. Domesticated pollinators offer wild pollinators fierce competition for resources, and can transmit destructive pathogens and parasites to them. We know that certain well-documented groups, like bumblebees, are in difficulty. But we have little knowledge about a number of other at-risk groups that are unfortunately receiving less attention.
You can help the pollinators in your vicinity by planting pollen-producing flowering plants – don’t plant double-flowered varieties: they produce less – and by avoiding the use of pesticides on your property. Take care of your pollinators, and you’ll be well rewarded!