Effect of Beauveria bassiana and Metarhizium anisopliae on different stages of Phlebotomus papatasi (Diptera: Psychodidae)

The sand fly, Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae), is the main vector of Leishmania major Yakimoff and Schokhor, 1914, the causative agent of zoonotic cutaneous leishmaniasis North Africa, the Middle East, and North Sinai. The purpose of this study was to determine the effect of fungi on P. papatasi larvae, pupae, and adults using light microscopic analysis, scanning electron microscope (SEM), and histopathological studies. Specifically, larvae, pupae, and adult P. papatasi were infected with the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. Scanning electron microscope and histopathological methods were used to investigate the destructive impact of the fungi on the external and internal structures of P. papatasi. The results revealed propagation of the conidia on the cuticles of all P. papatasi life stages, including on the compound eyes, leg setae, thorax, wings, and abdomen of the adults. Histological sections of the control and treated larvae, pupae, and adults showed many alterations and malformations in the body and tissues of all life stages after 72 h. These results demonstrated that B. bassiana was more effective than M. anisopliae as a biological control of phlebotomine sand flies. Further studies to determine the best methods for delivery and application in the diverse ecological settings of the various leishmaniasis vectors are recommended.