The study included diagnosing and recording an insect Tanaecia pelea. On Artemisia plants in Nineveh Governorate, which was attacking Artemisia plants in Nineveh Governorate for the year 2022, and the results showed the presence of the insect in nurseries in Nineveh Governorate from the date of 3/1/2022, in numbers that ranged from 1 larva on 3/1/2022, and its numbers increased on 5/20. In 2022, there were 60 larvae compared to the number of adults, which ranged from 4 to 25 adults, depending on the temperature and relative humidity. This was confirmed by the correlation values between temperature and relative humidity, as the values for larvae reached 0.70 for temperature and relative humidity -0.78, for adults 0.79 and -0.65, respectively. In addition to studying the diagnosis of the insect based on molecular characteristics, the results were shown when using polymerase chain technologyPCR in diagnosing the insect on Artemisia plants in Nineveh Governorate, as the match rate reached 99%, according to the tree branch of that insect.