Vol. 11, Special Issue 8 (2022)

Author(s):
Kumbhani MB and Shinde CU

Abstract:
An investigation of the population of Niger aphid, Uroleucon compositae (Theobald) revealed that the aphid population commenced from the 4th week after sowing (WAS) i.e., the fourth week of December (51^st SMW) with 0.08 aphids per leaf. The population of aphids increased slowly and reached its peak level (42.59 aphids/leaf) at 11^th WAS. It disappeared during the 10^th SMW (the Second week of March). The activity of the ladybird beetle, C. sexmaculata and green lacewing, Chrysoperla sp. showed a significantly positive correlation with the aphid population. Among the abiotic factors, minimum temperature had a significantly positive correlation with aphid during the study period, while minimum and average temperature showed a significantly negative correlation. The population of the ladybird beetle, C. sexmaculata was started in the 5th WAS (52^nd SMW) with an initial population of 0.02 adults per plant and the highest population was recorded at the 11^th WAS (0.26 adult/plant). It disappeared in the first week of March (10^th SMW). The predator, C. sexmaculata had a significantly negative correlation with maximum temperature, minimum temperature and average temperature. The population of green lacewing was recorded as 0.02 adults per plant at 6^th WAS (1^st SMW) and consciously increased till (0.14 adult/plant) 11^th WAS (6^th SMW). There was a rapid decline in the predator population and it disappeared in the fourth week of February (9^th SMW). Further, Chrysoperla sp. had a significantly negative correlation between maximum temperature and average temperature.