Ants killing hibiscus flowers

Ants are some of the most common pests in a majority of households, however most people ignore the ants. It is not advisable to ignore the ants attacking a hibiscus plant as all the flowers are rapidly dying after the ant attack. The ant attacking the hibiscus plants are larger than the common ants in India. These ants are covering the tips of the hibiscus stems with a white substance which cannot be easily identified.
Earlier the hibiscus plant was bearing flowers daily, there are almost no flowers.
The occasional flower that will bloom on the plant will be very small, in contrast to the large flowers which were blossoming when the plant was first purchased.