Bionomics of safflower aphid (Uroleucon compositae Theobald) on safflower crop

Abstract

An investigation into the life cycle of the safflower aphid, Uroleucon compositae Theobald, was carried out in a laboratory setting at the Department of Entomology, College of Agriculture, Raipur, Chhattisgarh, during the rabi season 2023-24. The aphid had progressed through four nymphal stages, starting with the first stage, which was elongated, wingless, transparent, and pale brownish or reddish in colour, changing to dark brown as it developed. The second instar nymph resembled the first instar in appearance, though slightly swollen, whereas the third instar featured round, reddish-black compound eyes that were significantly larger than those of the second instar. The fourth instar had a general appearance similar to that of the third. The nymphs measured 1.03 to 2.33 mm in length and 0.55 to 1.27 mm in width, lasting for a total of 7 to 12 days. This adult U. compositae insect had a shiny black body that was spindle-shaped to elongated and pyriform, measuring 2.41 to 2.75 mm in length and 1.11 to 1.27 mm in width, survived for 5 to 13 days, and produced 11 to 57 nymphs over its lifespan, with a generation period of 12 to 25 days.