August Species Spotlight: Highbush Blueberry and Spotted Wing Drosophila

August 31, 2022

Highbush blueberry (Vaccinium corymbosum)

Highbush blueberries are native to the state of NY and much of eastern North America from Nova Scotia, south to Georgia, and west to Wisconsin. They are deciduous shrubs that can grow between 6-12 feet tall and can be found in a variety of environments from the understory of pine and oak forests to wetlands like marshes and bogs and even the exposed sides of rocky cliffs, ravines, or dunes.

Notable highbush blueberry bogs occur locally in the Shawangunk Mountains and Hudson Highlands, a great place to see them is at Minnewaska State Park. Wherever they grow, they prefer more acidic soil (hence their tendency to grow along pines) and tend to prefer moist conditions.

In the spring, this tall woody plant comes alive as red tinted green leaves emerge that gradually turn to a deep blue/green over the summer. Pale white to pink, bell shaped flowers bloom during the late spring and hang droopily from the branches for about two weeks. Based on their shape, it is easy to imagine these flowers developing into the summer fruit we all love, blueberries.

High bush blueberry flowers provide nourishment for a variety of beneficial insect pollinators like bumblebees, miner bees (solitary bees that make up 54% of NY’s bee population) and honeybees – but the plants themselves also serve as a food source for many native butterfly and moth caterpillars. In addition to the insects that rely on this plant, blueberry is equally as important to a variety of mammals and birds that eat the ripened fruit during the mid to late summer like New York’s state bird; the Eastern Bluebird, as well as black bear, skunk, squirrel and many more. This plant even has value in the wintertime, when it is browsed upon by white tailed deer and cottontail rabbit.

 

Spotted Wing Drosophila – (Drosophila suzukii)

The genus Drosophila consists of a variety of species known as fruit flies. The spotted wing drosophila, native to Japan, is of particular concern in NY and other agricultural states. Unlike some of their harmless relatives who lay their eggs on rotting fruit, this species lays their eggs on unripe fruit – frequently before it has been harvested. They are partial to fruit that ripens later in the summer like the fruit we cover above: highbush blueberry, as well as raspberries, and a variety of stone fruits.

When these fruit flies lay their eggs, it forms small scars on the exterior of the fruit, but the real effects occur when the larvae hatch and feed upon the interior. This forms pits and voids within the fruit itself and hastens decay as well as the growth of molds and other fungi.

These insects are small but can cause mighty damage, agricultural infestations can result in the loss of up to 80% of the fruit harvest. Clocking in at less than 1/8^th of an inch – it can be difficult to determine if they are present in a fruit fly population with the naked eye. Thankfully though, in this case a simple DIY fruit fly trap of red wine vinegar will ensnare them for identification. Once their presence is confirmed, disposing of any visibly infected fruit, and treating plants with an insect repellent (natural or otherwise) has proven to be successful.

Are the fruits in your home garden rotting before you get a chance to harvest? Check out this link for instructions on how to build your own spotted wing drosophila trap, and for handy tips on how to ID the species.

 

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Blueberry Resources:

https://guides.nynhp.org/highbush-blueberry-bog-thicket/#range

https://www.wildflower.org/plants/result.php?id_plant=vaco

https://www.inaturalist.org/guide_taxa/329010

https://plants.ces.ncsu.edu/plants/vaccinium-corymbosum/

 

Spotted Wing Drosophila Resources:

https://www.wnyprism.org/invasive_species/spotted_wing_drosophila/

https://nysipm.cornell.edu/agricultural-ipm/fruits/pest-alerts-fruits/spotted-wing-drosophila/

https://cals.cornell.edu/pollinator-network/ny-bee-diversity