Susceptibility of Rhodnius prolixus (Hemiptera: Reduviidae) to the action of Triflumuron

Abstract

The effect of the insecticide Triflumuron (TFM) (lnsect growth regulator) (Staricide 480 S.C.) on 5lh instar nymphs of Rhodnius prolixus under laboratory conditions was evaluated. The insect colonies were maintained in an acclimatized camera (WTBbinder 78532 Tuttlingen Germany) with temperature of 26.5ºC and relative humidity (RH) of 80%, under darker conditions. They were fed with mouse blood (Mus musculus) from 2 at 3 hours. in the Mycology Laboratory at the Biology Institute, University of Antioquia, Medellín, Colombia. The treatment consisted of direct contact of the TFM on an insect with doses such as 0.0125, 0.025 and 0.05 µ.g/µ.l. 60 insects were used as control, they were treated with distilled water. In relation to mortality there were significant differences among the five treatments included the control (X² = 48.64, P < 0.0001). The 0.0125 µ.g/µ.l. dose caused the greatest percentage of mortality (96.5%). The LT50 for the doses 0.0125, 0.025, and 0.05 µ.g/µ.l was 10, 13, and 21 days. respectively. Equally, significant differences were found, in time at the molting stage at doses of 0.0125, 0.025 and 0.05 µ.g/µ.l and the control (X² = 69.24, P < 0.0001). The dose 0.05 µ.g/µ.l.presented the greatest number of insects with morphological alterations 15 ( 18. 75%). The results of this study showed that the insecticide TFM could be considered as an alternatíve for the control of R. prolixus.