Officials detail plan to control strawberry guava on Big Isle
HILO » The Big Island can use a Brazilian bug to control invasive strawberry-guava trees and also protect the tree's fruit for home use, state and federal officials told residents at a meeting Thursday night at the University of Hawaii at Hilo.
The aphidlike bug, with the scientific name Tectococcus, spreads slowly and will probably take decades to reach all parts of the native forest that strawberry guava has invaded, said U.S. Forestry Service researcher Tracy Johnson.
Meanwhile, anyone who wants to keep the bug away from strawberry guavas around their home can use agricultural oil sprays, which include organic sprays, he said.
The meeting, moderated by state Rep. Clifton Tsuji, was called to provide more information because some residents see Tectococcus as threatening the non-native fruit, which is considered a culturally important food source.
Besides use by home growers, the fruit is used casually by hunters and others when hiking through forests. The fruit is not used commercially to make "strawberry guava" drinks, which are a mix of strawberries and the large yellow "common" guava.
Tectococcus is a highly specialized insect and cannot live on common guavas or related plants, Johnson said.
Female Tectococcus insects form a "gall" or blister on the leaves of strawberry guava plants and live inside the gall the rest of their lives, Johnson said. When their eggs hatch, the tiny babies crawl out and move to other parts of the leaf.
Wind can blow them to other guava plants, but that is successful only in thickets inside native forests. The babies would have a hard time reaching more widely separated guavas around people's homes, Johnson said.
Infected trees are weakened but do not die. Therefore, they do not create a fire hazard or a space in forests for other invasive plants to move into, Johnson said.
While some people worry about the loss of a food source, strawberry guavas are actually blocking the development of commercial fruit orchards because the guavas harbor fruit flies which attack commercial crops, said retired federal researcher Julie Denslow.
Due to public concern over the project, additional public comment will be taken at a later date.