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

Abstract

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 21^st of July, the 18^th of August, the 17^th of November, and the 1^st of December, and five peaks of abundance on Washington navel occurred on the 14^th of July, the 25^th of August, 8^th of September, 22^nd of September and 6^th of October respectively, while recorded five peaks of abundance on Tarocco, occurred on the 30^th of June, the 21^st of July, the 1^st of September, the 15^th of September, and the 10^th of November. Moreover four peaks of abundance recorded on Hasna occurred on the 14^th of July, the 11^th of August, the 25^th of August, and the 1^st of September, and P. citrella prepupa recorded four peaks of abundance on citrus lemon that occurred on the 7^th of July, the 25^th of August, the 27^th of October, and the 1^st of December, and three peaks of abundance on Washington’s navel occurred on the 7^th of July, 14^th of July, and 20^th of October and recorded three peaks of abundance on Tarocco occurred on the 30^th of June, the 7^th of July, and the 20^th of October, while recorded on Hasna three peaks of abundance occurred on the 7^th of July, the 11^th of September, and the 20^th of October. While P. citrella Pupa recorded five peaks of abundance on citrus lemon occurred on the 16^th of June, 30^th of June, 10^th of January, 17^th of January, and 8^th of March, and recorded five peaks of abundance on Washington's navel occurred on the 22^nd of May, 9^th of June, 16^th of June, 30^th of June and 7^th of July and recorded four peaks of abundance on Tarocco occurred on the 9^th of June, the 30^th of June, the 20^th of October, and the 27^th of October while recorded three peaks of abundance on Hasna occurred on the 30^th of June, the 7^th of July, and the 20^th 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.