Insect release proposed to control exotic strawberry guava

May 22, 2008

U.S. Forest Service scientists with the Institute of Pacific Islands Forestry have submitted a proposal to release a Brazilian insect to control the spread of strawberry guava, a South American tree that has invaded and degraded native Hawaiían ecosystems since it was introduced in 1825 as a garden plant.

The scientists are working in collaboration with the Hawaií Department of Land and Natural Resources, and Hawaií Department of Agriculture, agencies responsible for issuing permits authorizing release of the insect on Hawaiían Islands. Initial release of the insect is proposed for this summer in the Ola’a Forest Reserve on the Big Island.

Land managers are particularly concerned about the plant because it has potential to invade nearly half the state’s land area, forming dense thickets that crowd endangered native species and impede access to residential property. Past control methods have been limited to removal by hand, herbicides and bulldozers.

Strawberry guava also affects Hawaiían cultural practitioners who can no longer collect native plants once found in abundance in forests. In addition, it hosts non-native fruit flies that have cost the state billions of dollars in lost agricultural revenue.

Institute of Pacific Islands Forestry scientists were tasked with finding a biocontrol agent for strawberry guava to protect remaining native ecosystems, improve control of fruit flies and reduce dependence on chemical herbicides. Biocontrol agents in Hawaií have been used for more than a century, including for control of prickly pear cactus, lantana, banana poka and ivy gourd.

Non-native plants became invasive in Hawaií because they escaped the animals, insects and diseases that naturally kept them in check so the scientists traveled to Brazil where insects evolved to prey specifically on the tree.

Field research yielded the insect Tectococcus ovatus, or the Brazilian scale, which hatches nymphs that settle on strawberry guava leaves, inducing the plant to build a bubble-like gall to enclose it. The plant’s vigor is reduced and it stops producing fruit, decreasing its spread over a period of years. The insect does not kill the plant outright.

Observations in Brazil that began in 1993 and testing at the Hawaií Volcanoes National Park Quarantine Facility the past six years have shown the insect is highly host-specific and will only attack strawberry guava, not common guava or other members of the plant’s family in Hawaií.

Source: US Forest Service

Explore further: Pact with devil? California farmers use oil firms' water

Related Stories

SemanticPaint system labels environment quickly online

29 minutes ago

Ten researchers from University of Oxford, Microsoft Research Cambridge, Stanford, and Nankai University have presented a new approach to 3D scene understanding with a system which they dubbed SemanticPaint. ...

Old World monkey had tiny, complex brain

29 minutes ago

The brain hidden inside the oldest known Old World monkey skull has been visualized for the first time. The creature's tiny but remarkably wrinkled brain supports the idea that brain complexity can evolve ...

Recommended for you

Gimmicks and technology: California learns to save water

Jul 03, 2015

Billboards and TV commercials, living room visits, guess-your-water-use booths, and awards for water stinginess—a wealthy swath of Orange County that once had one of the worst records for water conservation ...

Cities, regions call for 'robust' world climate pact

Jul 03, 2015

Thousands of cities, provinces and states from around the world urged national governments on Thursday to deliver a "robust, binding, equitable and universal" planet-saving climate pact in December.

Will climate change put mussels off the menu?

Jul 03, 2015

Climate change models predict that sea temperatures will rise significantly, including in the tropics. In these areas, rainfall is also predicted to increase, reducing the salt concentration of the surface ...

As nations dither, cities pick up climate slack

Jul 02, 2015

Their national governments hamstrung by domestic politics, stretched budgets and diplomatic inertia, many cities and provinces have taken a leading role—driven by necessity—in efforts to arrest galloping ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Egnite
not rated yet May 23, 2008
This sounds a little too easy a solution. I wonder what consequences there will be?
Star_Gazer
not rated yet Jun 04, 2008
plants will mutate, mobilize and develop thirst for human blood.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.