Contribution of insect pollinators

Insect pollination also known as Entomophily is an indispensable factor in the functioning of ecosystem service rendered by biodiversity .  It presents also a vital mechanism to agricultural production systems with 75% of varieties of plants benefiting from insects Pollinators to insure their reproduction  . This benefit is reciprocal , however the flowers provides insect pollinators with rich nutrients (nectar and/or pollen) .Sugary nectar supplies pollinators with carbohydrates ,while pollen offers proteins, fats, vitamins and minerals . Bees are the predominant insects pollinators  , they are not only crucial for the environment balance but also to the economy .

In fact, it is estimated that Honey bees, bumblebees and wild bees, bring out at least 22 billion EUR each year to the European agriculture industry 5. Considering that it has nutritional values very beneficial to human health, the honey is one of the most consumed and commercialized product, in fact the European Union is the second largest honey producer behind China. There are 600 000 beekeepers and 17 million hives in the EU producing around 250 000 tons of honey every year. Despite this the European production is not satisfied. In 2016, the EU imported about 200 000 tons of honey, 40% of which came from China, according to the European parliament 6.For this reason, guidelines for the general and specific compositions of the main honey varieties that can be marketed in European countries was established by the Commission of the European Communities in Council Directive DENLEG 2000/ (Council Directive, 2000)  in order to control the quality of honey and limit the risks of fraud. The floral origin, physicochemical properties, organoleptic characteristics and regional provenance are the main characteristic that must be indicated . Honey quality depends mainly on physicochemical parameters, organoleptic properties and geographic provenance .  The pollen analysis is also another determining factor of honey quality. It is a critical point in the delimitation of hygienic aspects  and determination of honey extraction and filtration . It can be also useful to detect some kinds of adulteration . Pollen analysis of honey or Melissopalynology, is the most common method for identification of the botanical origin.

Nonetheless, an in-depth knowledge of the bioregion and taxa of interest is required to utilize this method . This is why recent researches have proposed replacing this method by a DNA metabarcoding high throughput sequencing (HTS) approach using

the nuclear barcoding marker ITS2  , as an efficient alternative to identify the botanical origin of pollen in honey bee-collected pellets .