Flower preferences among weed-visiting insects in field edges

The increased improvement of weed control throughout the years has led to a decrease in the amount of weed in arable fields. Weeds can be a source of pollen and nectar. Pollinating insects are dependent on a variety of plants for nectar and pollen. This study evaluated the arable field weed flower preference among pollinating insects, through mostly observational studies in July 2020 in southern Sweden. Out of the 12 weed species that were observed, 5 got many visits from pollinated insects, while 4 got almost no visits. From these visits, I calculated which preferences each observed insect group had regarding weed species. I found that Syrphidae preferred Matricaria chamomilla, Apis mellifera preferred Centaurea cyanus and Lamium purpureum, Coleoptera preferred Cirsium arvense, other Diptera preferred Cirsium arvense, and Bombus preferred Galeopsis tetrahit. This indicates that if the weed species Matricaria chamomilla, Centaurea cyanus, Lamium purpureum, Cirsium arvense, and Galeopsis tetrahit are present in a conventional arable field pollinators are benefitted. The weed species Myosotis arvensis, Capsella bursa-pastoris, Thlaspi arvense, and Fumaria officinalis got almost no visits, which indicates that it is not as important to favour these weed species to benefit pollinating insects. Out of the surveyed weed species preferred by pollinators, the species Lamium purpureum and Galeopsis tetrahit had among the highest occurrences in arable fields, which means that these species have the possibility to benefit pollinators if weed control is occasionally abstained for a year