Oct 24

November 2013 Pest of the Month

Source: J. Jeffrey. Strawberry guava forms dense thickets that overwhelm and choke out native species.

Biological Control Release of Tectococcus ovatus, a Gall-forming Scale Insect to Aid in the Control of Strawberry Guava (Psidium cattleianum) in Hawaii. 

Strawberry guava was introduced to yards and gardens of Hawai‘i in 1825. Since then, it has spread into moist and wet forests statewide. Strawberry guava is killing and replacing native forests by forming dense, single-species thickets.

Biocontrol insect to control the spread of strawberry guava.
The biocontrol selected and tested for release is a scale insect. The newly-hatched nymphs crawl to young strawberry guava leaves, forming “galls”, and they reduce plant vigor by diverting resources normally used for plant growth and reproduction. Strawberry guava is the only plant in Hawai‘i that this insect is able to feed and make galls on.

Source: USDA Forest Service. Note leaf galls on strawberry guava (below) and lack of galls on common guava (above)

Decreased plant vigor will slow the spread of this plant, which will allow koa, ‘ōhi‘a and other native forest plants to survive and better compete for space, sunlight, and water.  Decreased plant vigor will also decrease the number of seeds produced. This will allow land managers to achieve better

For full length article click on link – November 2013 Pest- Strawberry Guava Biocontrol

Source: “Biological Control Release of Tectococcus ovatus, a Gall-forming Scale Insect to Aid in the Control of Strawberry Guava (Psidium cattleianum)”.  Prepared by DLNR, CGAPS, and Forestry and Wildlife Hawaii.
Biocontrol of Strawberry Guava by its Natural Control Agent for Preservation of Native Forests in the Hawaiian Islands State of Hawai‘i” June 2010, Prepared by Robert B. Rechtman, Ph.D., Frances Kinslow (USDA Forest Service), and Ron Terry, Ph.D.(Geometrician Associates)

For more information check out this video: http://www.youtube.com/watch?v=j-EdRCUEYRs