Population dynamics of the citrus leaf miner <i>Phyllocnistis citrella</i> (Lepidoptera: Gracillaridae) on four citrus crops in the Surman region, Libya

The present study aimed to investigate the population abundance of the citrus leaf miner (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillaridae), and determine the number of mines/leaflets on the studied host plants in the Surman region. Four citrus species were selected as host plants, and 100 infected leaves were collected from each host plant. Samples were kept in plastic bags and transferred for examination in the laboratory. The results showed that P. citrella larvae recorded four peaks of abundance on lemon occurred on the 21st of July, the 18th of August, the 17th of November, and the 1st of December, and five peaks of abundance on Washington navel occurred on the 14th of July, the 25th of August, 8th of September, 22nd of September and 6th of October respectively, while recorded five peaks of abundance on Tarocco, occurred on the 30th of June, the 21st of July, the 1st of September, the 15th of September, and the 10th of November. Moreover four peaks of abundance recorded on Hasna occurred on the 14th of July, the 11th of August, the 25th of August, and the 1st of September, and P. citrella prepupa recorded four peaks of abundance on citrus lemon that occurred on the 7th of July, the 25th of August, the 27th of October, and the 1st of December, and three peaks of abundance on Washington’s navel occurred on the 7th of July, 14th of July, and 20th of October and recorded three peaks of abundance on Tarocco occurred on the 30th of June, the 7th of July, and the 20th of October, while recorded on Hasna three peaks of abundance occurred on the 7th of July, the 11th of September, and the 20th of October. While P. citrella Pupa recorded five peaks of abundance on citrus lemon occurred on the 16th of June, 30th of June, 10th of January, 17th of January, and 8th of March, and recorded five peaks of abundance on Washington's navel occurred on the 22nd of May, 9th of June, 16th of June, 30th of June and 7th of July and recorded four peaks of abundance on Tarocco occurred on the 9th of June, the 30th of June, the 20th of October, and the 27th of October while recorded three peaks of abundance on Hasna occurred on the 30th of June, the 7th of July, and the 20th of October respectively, further, recorded an increase in the number of mines in autumn and summer in all host plants in the study, while decreasing the number of mines during the winter for both Abusora, Washington Navel, and Tarocco. and at the beginning of spring in lemon and the late autumn for Hasna blood orange.