Invasive fruit fly found in North Carolina

Oct 19, 2010

(PhysOrg.com) -- A potentially important invasive insect species – the fruit fly Drosophila suzukii, or spotted wing Drosophila (SWD) – winged its way to North and South Carolina this summer. The insect has the potential to cause up to 20 percent crop loss in host fruit.

So far, damage caused by the insect has been uneven.

Dr. Hannah Burrack, extension specialist and assistant professor of entomology, and colleagues found the first significant SWD larval infestation of fruit at the Upper Mountain Research Station in Ashe County, N.C., last month. Blackberry, raspberry and strawberry research plots were heavily infested, she found.

It was a different story at the Sandhills Research Station in Montgomery County, N.C., however. Some adult flies were trapped, but Burrack and her team found minimal larvae infestation of crops at the Jackson Springs, N.C., station. Burrack says the record-high temperatures may have prevented SWD from taking hold in the Sandhills.

SWD is bad news for small fruits; it feeds on blueberries, blackberries, raspberries, strawberries, grapes, peaches, pears, apples, cherries and other soft-skinned fruits, Burrack says.

SWD made its first appearance on the West Coast in 2008 and then appeared in Florida in 2009. Burrack implemented statewide programs to monitor and trap SWD this spring.

SWD is closely related to the fruit fly used as a type of “lab rat” in many academic studies – Drosophila melanogaster – but has some key differences that allow it to infest sound fruit, unlike all but one of the 1,500 other species of Drosophila. Most Drosophila feed on the micro-organisms that inhabit rotting fruit or plant tissue, and therefore are not typically crop pests, Burrack says.

Small fruit and tree fruit growers should carefully monitor their plantings for adult and larval presence, Burrack says. Growers should also monitor fruit for larval infestation. Large larvae will be visible in fruit, but small larvae may not.

“Larvae can most easily be detected via the ‘fruit dunk’ method,” Burrack counsels. “Fruit are gently crushed and floated in sugar water. After several minutes, larvae float to the surface and can be counted. It is important to remember that many native Drosophila feed on rotting fruit. Observing infestation in relatively sound fruit and confirming adult presence minimizes the likelihood that you will confuse SWD with native relatives.”

Sanitation is extremely important in managing SWD, Burrack adds. In areas where SWD is present, all ripe fruit should be removed from the field or plants should be treated with insecticide regularly, with the interval depending upon the material used. Unmarketable fruit should be destroyed or removed from the site.

Burrack adds that research from the West Coast shows many common insecticides are effective in combating SWD. She is currently preparing a document listing – by crop – the registered materials that are effective against SWD.

“Growers who have confirmed SWD should contact their county cooperative extension agent or myself for management recommendations,” she says. “It is especially important to rotate insecticides used to treat SWD to minimize the likelihood of resistance development.”

Explore further: Australian mosquito appears in California

More information: Burrack maintains a blog with useful information on SWD and other small fruit crops. It’s on the Web here.

add to favorites email to friend print save as pdf

Related Stories

Fruit fly pest identified in wine grapes

Oct 15, 2009

A newly recognized pest in Oregon continues to concern fruit growers and researchers with the recent discovery of a Spotted Wing Drosophila fly in a sample of Willamette Valley wine grapes.

Picky-eater Flies Losing Smell Genes

Apr 02, 2007

A UC Davis researcher is hot on the scent of some lost fruit fly genes. According to population biology graduate student Carolyn McBride, the specialist fruit fly Drosophila sechellia is losing genes for smell and taste receptors ...

Fruit fly hearts similar to human hearts

Feb 27, 2007

U.S. scientists say Drosophila fruit fly research may lead to new treatments for heart disease, the leading cause of death in industrialized nations.

Recommended for you

Global wild tiger population to be counted by 2016

19 hours ago

Thirteen countries with wild tiger populations agreed Tuesday to take part in a global count to establish how many of the critically endangered animals are left and improve policies to protect them.

Scientists discover tropical tree microbiome in Panama

Sep 15, 2014

Human skin and gut microbes influence processes from digestion to disease resistance. Despite the fact that tropical forests are the most biodiverse terrestrial ecosystems on the planet, more is known about ...

How are hybridized species affecting wildlife?

Sep 15, 2014

Researchers who transplanted combinations of wild, domesticated, and domesticated-wild hybridized populations of a fish species to new environments found that within 5 to 11 generations, selection could remove ...

User comments : 0