Many strawberry growers stock honey bees or even bumble bees to help supplement pollination; however, many native insects are often present that may be even more efficient strawberry pollinators than honey bees. Below is a list of insects that can be observed at strawberry flowers in North Carolina. While some species may pollinate for food, others may be pollinating by incidentally moving between flowers.

Managed bees:

Apis mellifera (Honey bee):

Honey bee visiting strawberry flower. Photo: Jeremy Slone

• Generalist feeder, capable of long distance foraging (1500+ meters).
• Continuous hive nesting with overlapping generations, and divisions of labor based on age.
• Eusocial – one queen and thousands of workers.

Bombus impatiens and B. bimaculatus (Bumble bees):

Bumble bee at strawberry flower. Photo: Jeremy Slone

• Generalist feeder, capable of long distance foraging (1500+ meters).
• Hive nesting with often only a single generation per year.
  • Only a newly mated queen survives through the winter, the rest of the colony dies.
• Eusocial – one queen and hundreds of workers.

Wild bees:

Many wild bees may pollinate strawberries. In general, wild bees have an average foraging range of 500 m, are smaller than honey or bumble bees, and often construct nests near the site of their emergence.

Wild bee. Photo: Jeremy Slone

Wild bee species known to forage on strawberries in the eastern United States include:

Andrena nasonii:

Andrena nasonii. Photo: Sam Droege

• Generalist, ground nesting bee.
  • Nests of Andrenid bees are often found near edges of woods or glades.
• Typically active in early spring (March-July).
• Eggs are laid in the spring and typically hatch into adults which stay underground until the following spring.
• Solitary – each female has her own nest, often near other nests in an aggregation.

Lasioglossum hitchensi:

Lassioglossum hitchensi. Photo: Brooke Alexander

• Generalist, ground nesting bee.
• Typically active from April-October.
• Eusocial – one reproductive and multiple foragers per nest

Augochlorella aurata:

Augochlorella aurata. Photo: Sam Droege

• Generalist, green “sweat bee.”
  • Soil nester, but the closely related species, Augochlora pura, nests in rotting wood.
• Typically active from April-October.
• Eusocial – one reproductive and multiple foragers per nest

Non bee pollinators

Many other insects in addition bees serve as pollinators. Some of the other pollinating insects observed in strawberries are:

Hoverflies (Syrphid fly) (Toxomerus marginatus and Syritta pipiens):

Syrphid fly adult (Family: Syrphidae). Photo: Jeremy Slone

Syrphid fly adult (Family: Syrphidae). Photo: Jeremy Slone

Butterflies (Vanessa virginiensis):

Butterfly adult (Family: Nymphalidae). Photo: Jeremy Slone

Predators and pests as pollinators?

Predatory insects may not serve primarily as pollinators in strawberries, but they may contribute to pollination when seeking prey or other food in flowers. Predatory insects observed on strawberry flowers include:

Lady beetles and their larvae (Coleomegilla maculata):

Lady bug adult (Family: Coccinellidae). Photo: Jeremy Slone

Lady bug larva (Family: Coccinellidae). Photo: Jeremy Slone

Soldier beetles (Chauliognathus pensylvanicus):

Soldier beetle adult (Family: Cantharidae). Photo: Jeremy Slone

Big eye bugs (Geocoris spp.):

Big eye bug (Family: Geocoridae). Photo: Jeremy Slone

Pests feeding on or near flowers may also contribute to pollination. Some of the pest insects observed in strawberry flowers include:

Lygus bugs (Lygus spp.):

Lygus bug (Famiy: Miridae). Photo: Jeremy Slone

Spotted cucumber beetles (Diabrotica undecimpunctata):

Cucumber beetle adult (Family: Chrysomelidae). Photo: Jeremy Slone

Strawberry clipper weevils (Anthonomus signatus):

Clipper weevil adults (Family: Curculionidae). Photo: Jeremy Slone

References:

• Ahrenfeldt, E. J., et. al. (2015). Pollinator communities in strawberry crops – variation at multiple spatial scales. Bulletin of Entomological Research, 105(4), 497–506.
• Linsley, E. G. (1958). The Ecology of Solitary Bees. Hilgardia, 27(19), 543–599.
• Renauld, M., Hutchinson, A., Loeb, G., Poveda, K., & Connelly, H. (2016). Landscape simplification constrains adult size in a native ground-nesting bee. PLoS One, 11(3).
• Mcglynn, E. (2009). Native bee benefits. Bryn Mawr College and Rutgers University.
• Mitchel, T. (1960,1962). Bees of the Eastern United States. NC Agricultural Experiment Station.

(Written by Jeremy Slone, August 2016)