Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

154 Biological Control of Insect Pests: Southeast Asian Prospects
species of ants are almost invariably in attendance on the mealybugs, namely
Solenopsis geminata and Pheidole megacephala (Serrano 1934). Three
predators from Hawaii were established in 1931 (Cleodiplosis koebelei:
Cecidomyiidae, Scymnus margipallens and Hyperaspis silvestri: both
Coccinellidae), but there is no information on their effectiveness (Clausen
1978).
PUERTO RICO
D. brevipes is the most serious pest of pineapples, attacking the roots, leaves
and fruits of all varieties grown. Anagyrus ananatis was imported in 1936
from Brazil and both A. ananatis and Hambletonia pseudococcina in 1937
from Hawaii where they had been introduced from Brazil and Venezuela
respectively. Both were released in 1937 and 1938. Only half grown or older
hosts were attacked by H. pseudococcina, the life cycle from oviposition to
adult emergence taking 24 to 30 days. In one instance, 3 parasitoids emerged
from the same host. Frequent recoveries were made from the field.
Development from egg to adult took 19 to 21 days for A. ananatis and the sex
ratio was 1:1 (Bartlett 1939). Recoveries of this species were reported later
(Bartlett 1943). The larvae of a tineid moth, a pyralid moth and of a
cecidomyiid fly were found living in the waxy secretions around large
groups of mealybugs and were thought to be predators. Three species of ants,
including Solenopsis geminata were frequently observed carrying young
mealybugs around. There do not appear to be any recent reports of the
effectiveness of the introduced parasitoids (Plank and Smith 1940).
SOUTH AFRICA
Larvae of the moth Drosica abjectella were observed preying on D. brevipes
on pineapple in the Transvaal. The number of moth larvae and pupae per
pineapple plant varied from 1 to 15 and these occurred in the leaf axils. Large
nymphs and fully-fed mealybug females were preferred and moth larvae
each consumed an average of 6.5 hosts in the laboratory. In winter,
development of fourth instar D. abjectella took 15 to 26 days, the prepupal
period 1 to 3 days and the pupal stage 35 to 45 days. The adults lived for 3 to
6 days (BŸttiker 1957).
SRI LANKA
Both a bisexual and a parthenogenetic strain of D. brevipes are present. The
former, which causes green spotting of pineapple leaves, occurs in the west
and the latter in the Bibile area (Carter 1956).
TAIWAN
D. brevipes is widely distributed on pineapple up to about 750 m and also
occurs on banana (Chiu and Cheng 1957). It appears that D. neobrevipes is
also present. Natural enemies include the cecidomyiid predator
Schizobremia formosana and also coccinellids, but these are less effective