Cotton is one of the major commercial crops cultivated in India. One constraint limiting the potential yield in cotton is due to the bollworm complex, among which pink bollworm (PBW), Pectinophora gossypiella (Saunders), is major. To reduce this impact of PBW, farmers have opted for chemical insecticides to manage the pest. Indiscriminate use of these insecticides has led to the problem of resistance. Hence continuous monitoring is a must to keep check on the changing status and trends in the resistance. In order to conduct laboratory studies, a uniform population of sufficient size, producing the insect in high numbers and throughout the year, is required. Hence, a semi-synthetic diet will greatly help in maintaining such populations in the laboratory. The protocol followed for the rearing has resulted in increased larval and pupal weights which depict the suitability of the semi-synthetic diet as well as the efficiency of the rearing technique. This study on the biology of PBW has revealed that the rearing protocol on semi-synthetic diet is ideal, and this has enables us to obtain maximum recovery (less mortality) in a short period of time under laboratory conditions.