Positive and Negative Impacts of Non-Native Bee Species around the World

Abstract

Though they are relatively understudied, non-native bees are ubiquitous and have enormous potential economic and environmental impacts. These impacts may be positive or negative, and are often unquantified. In this manuscript, I review literature on the known distribution and environmental and economic impacts of 80 species of introduced bees. The potential negative impacts of non-native bees include competition with native bees for nesting sites or floral resources, pollination of invasive weeds, co-invasion with pathogens and parasites, genetic introgression, damage to buildings, affecting the pollination of native plant species, and changing the structure of native pollination networks. The potential positive impacts of non-native bees include agricultural pollination, availability for scientific research, rescue of native species, and resilience to human-mediated disturbance and climate change. Most non-native bee species are accidentally introduced and nest in stems, twigs, and cavities in wood. In terms of number of species, the best represented families are Megachilidae and Apidae, and the best represented genus is Megachile. The best studied genera are Apis and Bombus, and most of the species in these genera were deliberately introduced for agricultural pollination. Thus, we know little about the majority of non-native bees, accidentally introduced or spreading beyond their native ranges.

Pollinator Diversity: Distribution, Ecological Function, and Conservation

“…The ecological effects of these introductions range from harmful to positive, depending upon the species, the context in which it was introduced, and (in particular) the local density of the pollinator (Russo 2016). The most abundant and impactful of these introductions has been the western honey bee (Apis mellifera), managed colonies of which are used to support agricultural pollination in parts of the world far outside its native range.…”

“…The diversity of pollinating insects has been artificially increased in some parts of the world by the introduction of non-native species, particularly bees (Goulson 2003, Russo 2016, either purposefully, to enhance crop pollination, or accidentally. In some oceanic islands introduced species can outnumber native pollinators; for example a recently published checklist of the bees of the Azores showed that of 19 species recorded (including managed hives of honey bees) only 4 were likely to be native (Weissmann et al 2017).…”

Range expansion of the Asian native giant resin bee Megachile sculpturalis (Hymenoptera, Apoidea, Megachilidae) in France

“…In addition, M. sculpturalis is now present in Austria, Italy, Germany, and Switzerland and is therefore well established in mainland Europe. Several bee species have been introduced, accidentally or deliberately, outside their native range due to human activities, mainly in North and South America and in Oceania (Goulson, 2003;Russo, 2016). In the northeastern USA, for example, Bartomeus et al (2013) identified 20 bee species not native to the USA.…”

“…In contrast with North and South America, where many introduced bees have been detected, bee introductions have been rare in European countries. To our knowledge (Goulson, ; Russo, ), M. sculpturalis is the first introduced bee species in Europe, where it has been detected for the first time in 2008. The observation occurred in Allauch near Marseille, France (Vereecken & Barbier, ).…”

Newly released non‐native dung beetle species provide enhanced ecosystem services in New Zealand pastures

“…Insects are a highly species‐rich part of terrestrial ecosystems, and their positive contributions to a wide range of ecosystem services have been highlighted (Losey & Vaughan, ; Kremen & Chaplin‐Kramer, ; Nichols et al ., ). About 3000 non‐native insect species have been deliberately introduced into many countries to improve three ecosystem services: biological control of pests or weeds (Hajek et al ., ), pollination (Russo, ), or decomposition (Hanski & Cambefort, ). The vast majority of deliberate releases of non‐native insects targeted at improving ecosystem services have been for biological control of pests or weeds (Winston et al ., ; Cock et al ., ).…”