Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

312 Biological Control of Insect Pests: Southeast Asian Prospects
development took 23 to 27 days and adults survived 4 to 9 days at 28 ± 2¡C
(Krishnamoorthy and Mani 1989a). In 1991 in Karnataka, C. peregrinus was
more abundant than Leptomastix dactylopii on P. citri on lemon and acid
lime and was responsible for the decline of mealybug populations (Mani
1994).
C. peregrinus has been introduced into California (Flanders 1951), Italy
(Bartlett 1978) and Bermuda (Bennett and Hughes 1959).
Cryptolaemus montrouzieri Col.: Coccinellidae
This general predator of mealybugs, which also feeds on some other scales
(Eriococcus sp., Pulvinaria spp.) and aphids, is native to eastern Australia. It
is the most widely distributed of all natural enemies of mealybugs, a count in
1978, covering the past 80 years, listing more than 40 countries, geographic
areas or islands into which it has been imported. In many instances it was
introduced against mealybugs other than P. citri and sometimes against
coccids such as Pulvinaria spp., which produce egg masses similar to those
of mealybugs (Bartlett 1978).
Both larvae and adults feed voraciously on all mealybug stages, for
example a larva is recorded as consuming an average of 3331 host eggs
(Oncuer & Bayhan 1982) and females need to consume at least 8 P. citri for
normal egg production (Reddy et al. 1991). C. montrouzieri does not
distinguish between unparasitised P. citri and mealybugs parasitised by
Leptomastix dactylopii (Prakasan and Bhat 1985). Adults mate 1 or 2 days
after emergence and, 5 to 6 days later, females begin ovipositing in or near
host egg masses. About 100 eggs are deposited in 1 month. These hatch in 4
to 8 days, and wax-covered larvae develop in 12 to 20 days, so that the life
cycle can be completed in slightly less than a month (27.7 days at
25.5¡ ± 1¡C: Oncuer and Bayhan 1982), although there are usually only 4
generations a year. Development stops below 10¡C and freezing
temperatures are lethal. Pupae, and occasionally adults, are capable of
hibernating. Hot dry climates are tolerated, but high humidities are said to be
detrimental. C. montrouzieri thrives when host density is high and, under
these conditions, is capable of providing spectacular control. However its
searching ability and natural spread is poor, so it often dies out locally when
hosts become scarce (Bodenheimer 1928; Cole 1933; Mineo 1967).
Methods have been developed for the production of mealybugs and
C. montrouzieri that permit the production and release of large numbers of
the predators at low cost (Branigan 1916, Smith and Armitage 1920, 1931;
Fisher 1963; Chacko et al. 1978; Oncuer and Koldas 1981).