Activity of fungi was tested by spraying conidial suspensions
at six different concentrations between 106 and 3 × 108 conidia/ml
onto nymphs with a Potter spray tower (Burkard, Hertfordshire,
UK) corresponding to concentrations between 2.33 × 103 and
7 × 105 colony forming units (CFU)/cm2 treated surface. For each
repetition control insects were treated with water only. Nymphs
were aseptically dried for 30 min at 75% RH and 25 ◦C, placed on filter
paper in plastic Petri dishes (90 × 15 mm) and then incubated in
a chamber (33 × 37 × 22 cm) at 25 ◦C, >98% RH and 12 h photophase.
Humidity inside the test chamber was regulated with a saturated
solution of K2SO4 (Winston and Bates, 1960). The mortality was
monitored for 20 days. Dead triatomines were transferred to filter
paper in a Petri dish (90 × 15 mm), incubated in a moist chamber at
25 ◦C and 12 h photophase, and fungal development on the cadavers
was evaluated daily for 10 days.