Field Studies on Supper Parasitism of the Larval Pupal Endoparasitiod Opius pallipes on the Tomato Leaf Miner Liriomyza bryoniae and the Serpentine Leaf Miner Liriomyza trifolii in Libya

Abstract

Objectives: The present study aimed to investigate Super parasitism behavior of the larval pupal endoparasitoid O. pallipes  in the field on two leaf mining insect hosts L. trifolii and L. bryoniae in Alojelat region during the winter growing season 2016/2017 using Broad bean (Vecia faba), as a host plant. Methods: Broad bean (Vecia faba), was targeted as a host plant because it has a heavy infestation by the two leaf mining insects combined with a good population of O. pallipes. 100 parasitized larvae were collected. Larvae were checked and the number of the parasitoid immature stages were counted. Solitary parasitized and supper parasitized larvae were counted for the two insect hosts. Results: Super parasitism caused by O. pallipes  females on L. trifolii recorded high numbers during December and April and  reached its peak on December 31th  recording (36 superparasitized larvae/100 parasitized ones), while the host population recorded (136 L. trifolii larvae/100 leaflets) at the same time. Super parasitism decreased to its lowest number on March 4th  recording (6 super parasitized larvae/100 parasitized ones) where the host population recorded  (251 larvae/ 100 leaflets) at the same time. While, super parasitism caused by O. pallipes females on L. bryoniae recorded high numbers during December and April and reached its peak at December 17th recording (27 super parasitized larvae/100 parasitized ones), while the host population was (73 larvae/100 leaflets), The lowest number of super parasitism was observed on  March 11th (4.0 super parasitized larvae/100 parasitized ones) when  the host population was (142 larvae/100 leaflets) at the same time. Conclusion: O. pallipes females reached  its highest numbers at the low population levels of the insect host on either L. trifolii or L. bryoniae with low preference towards L. trifolii so, super parasitism by O. pallipes  recorded slightly high numbers on L. trifolii larvae compared with L. bryoniae.