Answer:
Protein
Step-by-step explanation:
Proteins are made up of polypeptide chains of amino acids.Therefore protein is the compound which supplies Nitrogen.
Basically a Amino acid of protein is made up of two basic functional groups;
The Amine group of NH2 and the COOH- groups,.
Other substituents to the central carbon are the hydrogen atom and the R-group which determines the nature of amino acids. It is the Nitrogen atom in the Amine group that is absorbed by these carnivorous insects for supply of needed Nitrogen in proteins.