LAUSR

Abstract This study evaluated the flight propensity of 6 isofemale lines of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) using a flight test developed as a quality control measure for mass reared Trichogramma wasps. The same isofemale lines were used in earlier work to determine fecundity in the laboratory and performance in the field. We used 5 isofemale lines from a Mediterranean climate, collected in Irvine, California, USA, and 1 isoline from a humid subtropical climate, collected in Piracicaba, São Paulo, Brazil. The flight propensity was assessed with a short-range flight test of the different isofemale lines at 2 different relative humidity levels, 80% and 30%. Relative humidity (RH) affected only the isofemale line from Piracicaba, and about 30% fewer insects flew in high RH conditions compared with low RH conditions. Relative humidity conditions did not affect the California isofemale lines, which showed a flight propensity above 75% in both RH conditions. These results showed that for some lines, environmental conditions at the release sites might adversely affect the flight propensity. However, just the flight test method was not sensitive enough to discriminate the lines with different field performances.