Bt Research 2015, Vol.6 No.2 1-10
ISSN 1925-1939
3
Figure 1 Habit of
Aceria guerreronis
(mandari) infested
coconut palm with tender nuts showing different stages of
infestation. A:
A. guerreronis
infested coconut palm; B: young
button (7 weeks old) showing characteristic V-shaped
(triangular) creamy white patch upon infestation; C: 9 weeks
old button with multiple V-shaped patches, and D: severely
infested button (11 weeks old) shows longitudinal cracks.
Bioassay
Before subjecting to bioassay, for acclimatization,
many consecutive generations of the mites were made
in the laboratory,
i.e.
in the artificial feeding set up
(Fig. 2). The feed used for bioassay was depicted in
Figure 4. The standardized mites (a mixed population
with specific counts for adult mites) were used for the
bioassay. A population of about 20 mature mites with
all successive generations was transferred per cm
2
on
the buttons. Each culture set-up for bioassay was
monitored up to 10 days,
i.e
., until the end of their
normal life. It was seen that only mites in the control
set-up were passed through all succeeding stages for
Figure 2 Young coconut button and glass rings used for
culturing
A. guerreronis.
A: a 30 days old button with perianth
region exposed; B: glass rings used for the culture of mites; C:
glass rings attached to the button and sealed with parafilm, and
D: culture set- up (with 4 buttons) in a tray.
Figure 3 Life cycle of
A. gurreronis
. A. female mite with eggs;
B. protonymph (larva); C. nymph (second install larva); D.
young mites; and E. mature mites.
next generation. About 23% of the mature mites
survived after 24 h treatment with 1.25 μg/cm
2
crude
Btk
-toxin (potato flour supplemented), with no
