Biology Reference
In-Depth Information
10.2.2
Passiflora tarminiana-Septoria passiflorae
Passiflora tarminiana
Coppens & V. E. Barney (banana passion flower, banana poka
vine;
Passifloraceae
), native to the Andes, is an aggressive invasive tropical vine in
Hawaii. It is invasive in disturbed areas and its effects include loss of biodiversity,
smothering of trees, and the encouragement of other invasive species such as feral
pigs that feed on the fruit (ISSG Database 2005). By 1983, more than 50,000 ha of
wet and mesic forests in Hawaii had become infested with
P. tarminiana
, costing the
Division of Forestry and Wildlife $90,000 annually to control this weed in just one
area, the Hilo Forest Reserve (Trujillo 2005). In 1991,
Septoria passiflorae
Syd. was
isolated from infected Hawaiian banana poka seedlings grown in Colombia.
Subsequent to the pathogen's importation to Hawaii, host-range tests, completed in
1994, confirmed its specificity to banana poka vine (Trujillo et al. 1994).
Septoria
passiflorae
was approved as a biocontrol agent for banana poka vine in 1995. Field
inoculations done in 1996-1997 using spore suspensions resulted in significant con-
trol of banana poka vines in the islands of Hawaii, Maui, and Kauai (Trujillo 2005).
In the Hilo Forest Reserve, Hawaii, biomass was reduced between 40 and 60%
annually after the first inoculations, and 4 years later, a 95% biomass reduction was
observed (Trujillo 2005). The introduction of
S. passiflorae
has resulted in the pres-
ervation of some endangered species and regeneration of the indigenous
Acacia koa
forest (the source of the most valuable timber species in Hawaii) while saving mil-
lions of dollars in weed-control cost and forest revitalization programs in Kauai,
Maui, and Hawaii (Trujillo 2005).
10.2.3 Ageratina riparia-Entyloma ageratinae
Ageratina riparia
(Regel) R. M. King & H. Rob. (mist flower, Hamakua “Pa-makani,”
Asteraceae
), a low-growing perennial with clusters of tiny white flowers, was acci-
dentally introduced into Hawaii in 1925. By 1972, mist flower infestations had
spread over 100,000 ha of range- and forestlands on the Hawaiian Islands (Morin et
al. 1997; Trujillo 1985). The foliar smut fungus,
Entyloma ageratinae
Barreto and
Evans was introduced to Hawaii from Jamaica in 1975 to control this aggressive
weed. Initially misnamed as a
Cercosporella
sp., the pathogen was renamed
E.
ageratinae
sp. nov. Barreto and Evans (Barreto and Evans 1988), based on physio-
logical host reactions rather than on morphological differences [Trujillo (2005)
calls the fungus
E. compositarum
f. sp.
ageratinae
]. After extensive host-range
studies confirmed that the pathogen was specific to mist flower, field inoculations
were made at infested sites throughout the Hawaiian Islands (Trujillo 2005).
Complete control of the plant was achieved in less than 7 months in wet areas and
within 3-8 years in dry areas. Biological control of mist flower has been an out-
standing success in Hawaii with extensive rehabilitation of the Hawaiian range-
lands (Trujillo 2005).
