Flight muscle dimorphism and heterogeneity in flight initiation of field-collected Triatoma infestans (Hemiptera: Reduviidae).

GUREVITZ JM; KITRON U; GURTLER RE

JOURNAL OF MEDICAL ENTOMOLOGY

Entomological Society of America

Año: 2007 vol. 44 p. 186 - 191

0022-2585

Recent experiments demonstrated that most Þeld-collected Triatoma infestans (Klug) (Hemiptera: Reduviidae) adults from northern Argentina either never initiated ßight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-tolength ratio (W/L), or chance. We examined whether bugs that never initiated ßight possessed developed ßight muscles, and whether ßight muscle mass relative to total body mass (FMR) was related to the probability of ßight initiation. Approximately half of the adults that never initiated ßight had no ßight muscles. The absence of ßight muscles was 2.4 times more frequent in males than females. Females had signiÞcantly larger ßight muscle mass than males. For both sexes, the frequency of bugs with no ßight muscles was spatially heterogeneous among individual collection sites. A logistic regression model of ßight initiation that included bothFMRandW/Lprovided a better Þt than models including either one of these predictors. FMR is a novel predictor of ßight initiation in Triatominae, with a stronger effect than W/L. The higher frequency of females initiating ßight in our experiments may be explained by females having ßight muscles more frequently than males, and having FMR and W/L values more suitable for ßying. These Þndings demonstrate that individuals and natural populations of T. infestans can differ dramatically with regard to ßight initiation. (Hemiptera: Reduviidae) adults from northern Argentina either never initiated ßight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-tolength ratio (W/L), or chance. We examined whether bugs that never initiated ßight possessed developed ßight muscles, and whether ßight muscle mass relative to total body mass (FMR) was related to the probability of ßight initiation. Approximately half of the adults that never initiated ßight had no ßight muscles. The absence of ßight muscles was 2.4 times more frequent in males than females. Females had signiÞcantly larger ßight muscle mass than males. For both sexes, the frequency of bugs with no ßight muscles was spatially heterogeneous among individual collection sites. A logistic regression model of ßight initiation that included bothFMRandW/Lprovided a better Þt than models including either one of these predictors. FMR is a novel predictor of ßight initiation in Triatominae, with a stronger effect than W/L. The higher frequency of females initiating ßight in our experiments may be explained by females having ßight muscles more frequently than males, and having FMR and W/L values more suitable for ßying. These Þndings demonstrate that individuals and natural populations of T. infestans can differ dramatically with regard to ßight initiation. Triatoma infestans (Klug) (Hemiptera: Reduviidae) adults from northern Argentina either never initiated ßight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-tolength ratio (W/L), or chance. We examined whether bugs that never initiated ßight possessed developed ßight muscles, and whether ßight muscle mass relative to total body mass (FMR) was related to the probability of ßight initiation. Approximately half of the adults that never initiated ßight had no ßight muscles. The absence of ßight muscles was 2.4 times more frequent in males than females. Females had signiÞcantly larger ßight muscle mass than males. For both sexes, the frequency of bugs with no ßight muscles was spatially heterogeneous among individual collection sites. A logistic regression model of ßight initiation that included bothFMRandW/Lprovided a better Þt than models including either one of these predictors. FMR is a novel predictor of ßight initiation in Triatominae, with a stronger effect than W/L. The higher frequency of females initiating ßight in our experiments may be explained by females having ßight muscles more frequently than males, and having FMR and W/L values more suitable for ßying. These Þndings demonstrate that individuals and natural populations of T. infestans can differ dramatically with regard to ßight initiation.T. infestans can differ dramatically with regard to ßight initiation.