Calotropis gigantea, commonly known as milkweed or swallow-worth, was a common wasteland weed and belongs to family Asclepiadaceae. It is commonly known as the Milkweed or Ak (Hindi) or Akon (Assamese). Being native to India, it grows wild up to 900 m throughout the country on a variety of soils and in different climates, sometimes where nothing else grows. Traditionally it was used to treat common diseases such as fever, leaves and flowers are to treat many diseases and abnormalities in humans. The damage causing insect is Corynodes peregrinus 34.41%. It is also observed that the host plant infested by the insects in the young leaf (25%), fruits (18.75%), flowers (6.25%), mature leaf (12.5%), basal stem (12.5%), middle stem (12.5%), Apical shoot (6.25%) and tender leaf (6.25%). The population density is evaluated and it is found that the highest population density is done by of Corynodes peregrinus in the month of July in all the survey zones of Guwahati.