Both Native and Introduced Non-Crop Flowering Plants Around Orchards Support Potential Crop Pollinators and Other Beneficial Insects

Abstract

Non-crop floral resources in agricultural areas play an important role in supporting crop pollinating taxa and increasing biodiversity. We studied flower-insect interactions to two spring flowering crops and accompanying non-crop flowering resources (introduced/native) in apple and blueberry orchards in southern Tasmania, Australia, to (i) identify the important crop pollinating taxa in this region and (ii) examine if crop and non-crop introduced and native flowering plants within orchards supported different community assemblages of flower-feeding insects. We found a high overall contribution to crop visitation by introduced honeybees (Apis mellifera), which dominated visitation to apple (91% of total visits) and blueberry (76% total visits). A second introduced bee, the earth bumblebee (Bombus terrestris), made up 19% of total visits to blueberry, yet rarely visited flowering apple. Reed bees (Exoneura) were the most frequent native bee visitor to both apple 2.5% and blueberry 4%. Non-crop flowering plants around orchards showed significantly different community assemblages of flower-feeding insects in comparison to flowering crops. These differences were shaped by high association of insects with certain vegetation types, including A. mellifera with flowering apple, B. terrestris with flowering blueberries, native reed bees (Exoneura) with flowering apple and native flowers, soil nesting halictid bees (Lasioglossum) with introduced and native flowers and hoverflies with flowering apple and introduced forbs.