Beauveria bassiana(Hypocreales: Cordycipitaceae) Reduces the Survival Time of Lutzomyia longipalpis(Diptera: Psychodidae), the Main Vector of the Visceral Leishmaniasis Agent in the Americas

Visceral leishmaniasis caused by Leishmania infantum(Kinetoplastida: Trypanosomatidae) is a major neglected tropical disease and Brazil is the responsible for most cases reported in the Americas. In this region, L. infantumis primarily transmitted by Lutzomyia longipalpisand Migonemyia migonei(França) (Diptera: Psychodidae) is considered a permissive vector. We evaluated the susceptibility of Lu. longipalpisand Mg. migoneito Beauveria bassianaand to Eucalyptus globulus(Myrtales: Myrtaceae) essential oil. A spore suspension of B. bassianawas prepared and sand flies divided into five groups: test 1 (107spores/ml of B. bassianawith E. globulusessential oil at 4 mg/ml), test 2 (107spores/ml of B. bassiana), test 3 (E. globulusessential oil at 4 mg/ml), positive control (cypermethrin 0.1%), and negative control (sterile distilled water). Scanning electron microscopy (SEM) was performed on specimens from each group. A 50% reduction was recorded in the survival time of Lu. longipalpisin test 1 and 2, where hyphal adhesion and cuticle damage were observed by SEM. No significant differences in the survival time of Mg. migoneiwere found, probable due to the high mortality rate observed in the negative control group, which may be a result of the greater sensitivity of this species to laboratory conditions. The results obtained herein suggest that B. bassianamay be a potential biological control agent against Lu. longipalpis, the main vector of L. infantumin the Americas.