PRELIMINARY SURVEY OF THE GREEN LACEWINGS (NEUROPTERA: CHRYSOPIDAE) IN CITRUS ORCHARDS IN NORTHERN EAST OF TUNISIA (CAP BON)

Aphids are one of the key pests affecting citrus in Tunisia. Nowadays, their control is mostly chemical. However, because of the need for a more sustainable citrus industry, other biologically-based control methods are under study. One of them involves the biological control by means of natural enemies. As a first step, increased knowledge on the actual diversity of natural enemies in this citrus system is needed. Because lacewings (Neuroptera: Chysopidae) are one of the most important group natural enemies of aphids, a survey of lacewings occurring in citrus orchards in NE Tunisia (Cap Bon) was conducted. Three organic and four conventional citrus orchards were compared during two consecutive years (2010, 2011). Adults were collected with a vacuum aspirator; whereas pre-imaginal instars were collected from aphid infested shoots. Six green lacewing species were identified: Chrysoperla lucasina, C. carnea, C. affinis, Dichochrysa flavifrons, Dichochrysa prasina and Chrysopa formosa. Chrysoperla lucasina was the dominant species (53%) in all orchards. Adults of the complex C. carnea were recorded from February to December and showed two peaks in May-June and in September.