Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

222 Biological Control of Insect Pests: Southeast Asian Prospects
Telenomus podisi and Gryon obesum parasitised up to 60% of Nezara eggs
on soybean (Correa and Moscardi 1995).
In southern Brazil, T. basalis is the main parasitoid, attacking between
97.5% and 100% of N. viridula eggs laid on soybean. In 1988, 36.6% of the
egg masses were attacked and 10.3% in 1989, with 21.8% and 6.3% of the
individual eggs being parasitised respectively (Foerster and QueirÏz 1990).
COOK IS
T. basalis was introduced to Mangaia in 1950, but is not known to have
become established (Cumber 1953; Walker and Deitz 1979) and this must be
assumed not to have occurred.
EASTER IS
Control of N. viridula was achieved by the establishment of the tachinid
Ectophasiopsis arcuata from mainland Chile, so that it is now difficult to
find a bug. T. basalis was also introduced but was not recovered (Ripa and
Rojas 1989; Ripa et al. 1992).
FIJI
N. viridula was first recorded in 1939 and Trissolcus basalis was introduced
from Australia in 1941 (Lever 1941). Success was immediate and good
control resulted (OÕConnor 1950). Large populations of N. viridula are
reported to develop sometimes on cowpeas, but the insect is not troublesome
on other legumes (Swaine 1971).
Trichopoda pennipes was introduced from Florida in 1949, but its
establishment is not recorded (OÕConnor 1950).
HAWAII
N. viridula was first recorded in 1961 and the wasps Trissolcus basalis,
Xenoencyrtus hemipterus (= X. niger) and Telenomus sp. (all egg
parasitoids) from Australia were released in 1962. Other importations in
1962 were the tachinid fly, Trichopoda pilipes, which parasities last instar
nymphs and adults, and two egg parasitic wasps Ooencyrtus submetallicus
and O. trinidadensis from the West Indies. In 1963 Trichopoda pennipes
was imported from Florida. Of these parasites, Trissolcus basalis,
Trichopoda pennipes and T. pilipes became established (Davis and Krauss
1964; Davis 1964, 1967; Croix and Thindwa 1967; Clausen 1978). Nezara
populations declined steadily to sub-economic levels, with only sporadic
outbreaks, and the species is generally under effective biological control
(C.J. Davis, pers. comm. 1985). Average parasitisation by Trissolcus basalis
ranged up to about 95% and by Trichopoda pilipes up to 86%. Trichopoda
pupae are occasionally parasitised by the encyrtid Exoristobia philippensis
(Davis 1964).
More recently (1990Ð91) egg rafts of N. viridula placed in weeds at the
border of macadamia nut plantations had significantly higher rates of