More than 40% of invertebrate species, especially bees and butterflies, which ensure pollination, are at risk of disappearing; in particular in Europe 9.2% of European bee species are currently threatened with extinction (IUCN, 2015). Without them many plant species would become extinct and current levels of productivity could only be maintained at very high costs through artificial pollination. Domestic and wild bees are responsible for about 70% of the pollination of all living plant species on the planet and guarantee about 35% of global food production.

Over the last 50 years, agricultural production has increased by approximately 30% thanks to the direct contribution of pollinating insects.

On a global scale, more than 90% of major crop types are visited by Apoidea and about 30% by Diptera (including flies), while each of the other taxonomic groups visits less than 6% of crops. Some bee species, such as the western honey bee ( Apis mellifera ) and the eastern honey bee ( Apis cerana ), some bumblebees, some stingless bees, and some solitary bees are domesticated; however, the vast majority of the world’s 20,077 known Apoidea species are wild.

Pollinators play a vital role in nature as a regulatory service to the ecosystem. It is estimated that 87.5% (about 308,000 species) of the world’s wild flowering plants depend, at least in part, on animal pollination for sexual reproduction, ranging from 94% in tropical plant communities to 78% in temperate zones (IPBES, 2017). It has been shown that 70% of the 115 globally important agricultural crops benefit from animal pollination (Klein et al., 2007); furthermore, the increase in the annual global monetary value of agricultural production amounts to about 260 billion euros (Lautenbach, 2012). In Europe, the production of about 80% of the 264 cultivated species depends on the activity of pollinating insects (EFSA, 2009).

The protection of pollinating insects, particularly bees and butterflies, is therefore of fundamental importance, as they play an important role in the pollination of a wide range of crops and wild plants.

Bees also provide precious hive products such as: honey, pollen, royal jelly, wax, propolis, venom, which have always been used and appreciated by man.

Most of the plants of agricultural interest need pollinating insects for pollination. Due to some choices of modern agriculture such as monoculture, the elimination of hedges and the use of pesticides, as well as the alteration and fragmentation of natural areas, the environment has become inhospitable for most pollinating insects.

The decline in the presence of wild pollinators has meant that the importance of Apis mellifera has become fundamental for some crops.

In Europe, almost half of insect species are in serious decline and a third are in danger of extinction. Habitat change and environmental pollution are among the main causes of this decline. In particular, the intensification of agriculture over the last six decades and the widespread and unstoppable use of synthetic pesticides are one of the main factors in the decline of populations and loss of biodiversity of pollinating insects in recent times.

The conclusion is clear: either we change the way we produce food now, or most insects will become extinct within a few decades.

The repercussions that this will have on the planet’s ecosystems in the coming years could be very serious, since insects are the structural and functional basis of most of the planet’s ecosystems.

Restoring natural habitats, together with a drastic reduction in agro-chemical inputs and agricultural “redesign”, is probably the most effective way to avoid further declines or disappearances of pollinating insects, especially in intensively agricultural areas.

For example, rows, hedgerows, and meadows planted at field margins increase the abundance of wild pollinators, and crop rotations with clover or other legumes can increase the abundance and diversity of bumblebees, which in turn improve crop yields and farm profitability. These “ecological engineering” practices not only benefit pollinators, but also conserve natural insect enemies that are essential for controlling herbivorous pest species that attack many important crops.

However, for these measures to be effective, it is essential that current pesticide use patterns, mainly insecticides and fungicides, are minimized to allow insect populations and their associated “biological control” services to recover.

In many of the world’s agricultural systems, biological control provides an underutilized but cost-effective and environmentally friendly means of solving crop pest problems that can preserve biodiversity both on and off the farm.

by V. Silli, V. Bellucci (ISPRA)

Sebastiano Sanna