Bioecological Study Of The Citrus Leafminer: Phyllocnistis Citrella Stainton (Lepidoptera: Gracillariidae) In Western Algeria

Abstract

Phyllocnistis citrella one the most important citrus pests in its native area of South east Asia. In Algeria, the first reports were noted in 1994 in citrus orchards. Since, the citrus leaf miner has spread to citrus growing areas causing considerable damage. It’s strictly endophytic lifestyle makes control difficult. A study of the biological cycle of this pest was studied in the ambient conditions of the laboratory, this revealed different life spans for the different stages: eggs, larva and pupa, the lifespan were respectively: 5 ± 4,3 d, 12± 4.5 d and 18± 9.5 d. The period of the cycle varies according to the climatic conditions. In our case, the biological cycle of this pest is 12 ± 5.2 d at a temperature of 30oC ± 1oC. The activity of P. citrella adults was observed right from the first sap flush with insignificant contamination rates and only on orange trees. This confirms that the spring shoots are spared from phytophagous attacks. Contaminations started on rebel shoots, with relatively low levels of infestation. But the latter constituted a base for the activities of the adults on the second flush of sap, the contamination rate of which reached 99% The inventory revealed the constant presence of three species of parasitoids dependent on P.citrella in the Mostaganem region: Cirrospilus pictus, Pnigalio pectinicornis and Semielacher petiolatus. Our results show that the parasitism rate goes from 70% to 69% after a few weeks and this proves that the method used is a very effective method.