title: Survival and immune response of the Chagas vector Meccus pallidipennis (Hemiptera: Reduviidae) against two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea.
abstract: BACKGROUND
  Chagas disease is a key health problem in Latin America and is caused and transmitted by Trypanosoma cruzi and triatomine bugs, respectively. Control of triatomines has largely relied on the use pyrethroids, which has proved to be ineffective in the long term. Alternatively, the use of entomopathogenic fungi has been implemented to control triatomine bugs. These fungi are highly efficient as they induce a reduction in immune response on insects. Meccus pallidipennis is the main triatomine vector of Chagas disease in Mexico. In this work we investigated the effects of two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea, on M. pallidipennis nymphs in terms of insect survival and immune response.
  
  
  METHODS
  We had an infected and a control group for each fungal species and assessed: a) insect survival during 30 days; and, b) phenoloxidase (PO) and prophenoloxidase (proPO; two key traits in insect immune response) at 24, 48, 96 and 144 h. For survival we used Kaplan-Meier survival analysis while for immune response we used factorial, repeated-measures ANOVA for each fungal species.
  
  
  RESULTS
  Animals treated with M. anisopliae died sooner than animals treated with I. fumosorosea. Infected animals showed lower PO and proPO values than sham individuals, with a clear decrease in these parameters at 24 h with no further changes after this time.
  
  
  CONCLUSIONS
  Our study widens the possibility of entomopathogenic fungi being used for triatomine control. The negative effect on PO and proPO seems mediated by a down-regulation of the triatomine immune response.
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico.
authors.forename: A Laura
authors.initials: AL
authors.lastname: Flores-Villegas
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico.
authors.forename: Margarita
authors.initials: M
authors.lastname: Cabrera-Bravo
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico.
authors.forename: Conchita
authors.initials: C
authors.lastname: Toriello
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico.
authors.forename: Martha I
authors.initials: MI
authors.lastname: Bucio-Torres
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico. pazmar@unam.mx.
authors.forename: Paz María
authors.initials: PM
authors.lastname: Salazar-Schettino
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico. acordoba@iecologia.unam.mx.
authors.forename: Alex
authors.identifier: http://orcid.org/0000-0002-5978-1660
authors.initials: A
authors.lastname: Córdoba-Aguilar
mesh_terms: D000818:Animals; D003140:Communicable Disease Control / Q000379:methods; D006999:Hypocreales / Q000472:pathogenicity*; D007303:Insect Vectors; D052981:Metarhizium / Q000472:pathogenicity*; D008800:Mexico; D009758:Nymph / Q000276:immunology / Q000382:microbiology; D010572:Pest Control, Biological / Q000379:methods; D016019:Survival Analysis; D014225:Triatominae / Q000276:immunology* / Q000382:microbiology*
keywords: Chagas disease; Entomopathogenic fungi; Meccus pallidipennis; Phenoloxidase; Prophenoloxidase; Survival