Seasonal incidence of aphid, Dactynotus carthami and coccinellids in correlation to weather conditions.
The investigations on seasonal incidence of safflower aphid, Dactynotus carthami along with coccinellids (predators) were carried out during the year 1975–76. The safflower aphid began appearing on leaf whorls in the first week of December. Its infestation increased touchiag peak between middle January to middle February. Population started declining there-after and ceased completely by the end of March. Population of aphids was observed to reach to its maximum when the temperature was 17° C and relative humidity ranged from 66 to 67 percent, which seem to be the optimum weather conditions for its growth and multiplication. With the fall in temperature and rise in humidity the population of aphids increased to a high level and with rise in temperature and fall in relative humidity the population of aphids showed a sharp decline. Thus. the rise in aphids population seems to be negatively correlated with the temperature and positivuly with humidity.