Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

302 Biological Control of Insect Pests: Southeast Asian Prospects
GREECE
INDIA
set. Mass rearing and release of Leptomastix dactylopii, which requires the
use of fewer mealybugs for laboratory rearing than the coccinellid
C. montruzieri and is cheaper, is preferred to that of the coccinellid if only
one natural enemy is to be used. However, it is preferable to employ both,
with C. moutrouzieri destroying high populations of females and eggs and
L. dactylopii parasitising nymphs, even if populations are scattered (Panis
1977, 1979).
Cryptolaemus montrouzieri was liberated against P. citri on potted orange
trees in a glasshouse at 25 to 30¡C and 55 to 70% RH and the results compared
with the release of Nephus (= Scymnus) reunioni or the application of
insecticide. C. montrouzieri significantly reduced mealybug populations
and was as effective as treatment with methidathion (Hamid and Michelakis
1994).
Leptomastix dactylopii was introduced in 1983 to Bangalore and rapidly
became established on P. citri on mandarins and coffee, causing up to 100%
parasitisation (Nagarkatti et al. 1992). Seven years later in 1991, P. citri was
being attacked on lemon and lime by L. dactylopii and the more abundant
indigenous Coccidoxenoides peregrinus, which was causing 10 to 30%
parasitisation. C. peregrinus attacks preferentially the early and Leptomastix
dactylopii the later instars (Krishnamoorthy and Mani 1989a; Mani 1994).
In 1984 L. dactylopii was released in a lime orchard in Karnataka. Prior to
release, infestation by P. citri ranged from 38 to 65%, but establishment of
the parasitoid led to excellent control within 4 months and no insecticides
were required in following seasons. The parasitoid was shown to have
migrated about 0.5 km in a 2-year period and a mean of 2.3 adult parasitoids
were recovered from each infested fruit in an orange orchard
(Krishnamoorthy 1990). Parasitisation of P. citri and other mealybugs on
coffee ranged, in different years, between 19 and 45% (Reddy et al. 1988)
and 0 and 85% (Reddy et al. 1992). Although L. dactylopii greatly reduced
the population of P. citri, augmentative releases were required for
continuing control in a coffee plantation (Reddy and Bhat 1993).
Native predators of P. citri on coffee include the lycaenid, Spalgis epius,
the coccinellid, Pullus pallidicollis, and the cecidomyiid Triommata
coccidivora (Prakasan 1987). On citrus the chrysopids Mallada boninensis,
Odontochrysa (= Chrysopa) lacciperda, Mallada basalis and Chrysoperla
carnea were found (Krishnamoorthy and Mani 1989b); and on guava
Odontochrysa lacciperda, Spalgis epius and Cryptolaemus montrouzieri
(Mani and Krishnamoorthy 1990).