Abstract:
The experiment was conducted at Entomology laboratory of Sher-e-Bangla Agricultural
University with the following treatments to understand the efficacy of different insecticidal
combination with wetting agents against nymph and adult of devastating mango mealybug.
The treatments consist of T
1
= Nitro 505 EC + Petroleum oil, T
= Nitro 505 EC + Ethyl
alcohol, T
3
= Nitro 505 EC + Detergent, T
4
2
= Capture 75 WG + Petroleum oil, T
= Capture
75 WG + Ethyl alcohol, T
6
= Capture 75 WG + Detergent, T
= Imitaf 20 SL + Petroleum
oil, T
8
= Imitaf 20 SL + Ethyl alcohol, T
9
7
= Imitaf 20 SL + Detergent. The study examined
the mortality rate of mealybugs by treating those combinations. Treatment T
consistently
showed the highest nymphal mortality rates across different application times, significantly
outperforming other treatments. Conversely, T
exhibited the lowest control of first instar
nymphs, with notably fewer nymphs controlled after 48 hours compared to other treatments.
T
3
and T
9
6
also showed significant results in nymphal mortality, gradually increasing over
time. While T
initially showed high nymphal mortality, it revealed statistically similar
results to T
1
, T
2
5
, T
4
, T
7
, and T
8
. T
performed the poorest, with the lowest control of second
instar nymphs after 48 hours, while T
9
3
and T
also demonstrated lower efficacy. Regarding
adult mealybugs, mortality rates were lower compared to nymphs, attributed to the
development of a protective waxy layer. Treatment T
6
showed the highest control of adult
mealybugs, followed by T
2
5
, with statistically significant differences observed. T
exhibited
the lowest control, significantly different from T
. Despite slight increases over time, all
treatments resulted in significantly lower numbers of adult mealybugs compared to the initial
12-hour application period. Overall, the study highlights the differential efficacy of
treatments in controlling mealybug nymphs and adults, with T
5
showing consistent
effectiveness against nymphs and T
being most effective against adult mealybugs.
5
8
8
5
6
