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: Tourists evacuated amid Iceland volcano concerns

add to favorites email to friend print save as pdf

Related Stories

Jurassic Welsh mammals were picky eaters, study finds

22 minutes ago

For most people, mere mention of the word Jurassic conjures up images of huge dinosaurs chomping their way through lush vegetation – and each other. However, mammals and their immediate ancestors were also ...

Myo armband and smartglasses set for deskless workplace

1 hour ago

Thalmic Labs, Canada-based makers of the Myo armband, has announced the integration of Myo with smartglasses, with the partnership help of a number of companies pairing the Myo with their products. The gesture-control ...

Recommended for you

NASA image: Signs of deforestation in Brazil

19 hours ago

Multiple fires are visible in in this image of the Para and Mato Grosso states of Brazil. Many of these were most likely intentionally set in order to deforest the land. Deforestation is the removal of a ...

Sunblock poses potential hazard to sea life

20 hours ago

The sweet and salty aroma of sunscreen and seawater signals a relaxing trip to the shore. But scientists are now reporting that the idyllic beach vacation comes with an environmental hitch. When certain sunblock ...

Is falling recycling rate due to 'green fatigue'?

21 hours ago

It's been suggested that a recent fall in recycling rates is due to green fatigue, caused by the confusing number of recycling bins presented to householders for different materials. Recycling rates woul ...

Study to inform Maryland decision on "fracking"

23 hours ago

The Maryland Department of Environment and Department of Health and Mental Hygiene released on August 18, 2014, a report by the University of Maryland School of Public Health, which assesses the potential ...

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.