Trichilia americana, ON, ON

García-Gómez, A., Figueroa-Brito, R., García Serrano, L. A. & Jiménez-Pérez, A., 2018, Trichilia (Meliaceae) plants: an important source of biomolecules with insecticidal properties, Florida Entomologist 101 (3), pp. 470-470 : 470-

EFFECT OF THE EXTRACTS OF TRICHILIA AMERICANA ON COPITARSIA DECOLORA SURVIVAL

Copitarsia decolora larvae fed on a diet supplemented with hexane extracts of T. americana displayed significantly reduced mean survival times (Log-Rank Test = 48.33; df = 4; P <0.001; Table 1 ; Fig. 2a ). Larvae fed the 1,500 ppm treatment had a significantly shorter mean survival time than the others, and all of them died as larvae. Larvae on the 100, 500, and 1,000 ppm treatments had similar survival times, but they were significantly shorter than the diet-only control treatment. Larval mortality was over 70% in all treatments except at 100, where larval mortality was 40%, and very few casualties were observed at the pupal stage. The cumulative mortality for the control diet treatment was 8%.

Larvae fed the 1,500 ppm ethyl acetate-extract treatment had the shortest mean survival time (Log-Rank Test = 42.61; df = 4; P <0.001; Table 1; Fig. 2b). All treatments had significantly shorter mean survival times than the control diet treatment. Larval mortality increased as concentration increased. No larvae from the 500, 1,000, and 1,500 ppm treatments reached the adult stage, and at 100 ppm, cumulative mortality was 76%.

Mean larval survival times were similar in all the concentrations of acetone extract (Log-Rank Test = 6.26; df = 4; P <0.18; Table 1) and mean survival time for larvae fed acetone extract was the same as the control diet treatment. The highest cumulative mortality was obtained in the 1,500 ppm treatment.

Mean survival times of C. decolora larvae were similar across all the concentrations of methanol extract (Log-Rank Test = 9.35; df = 4; P <0.053) and aqueous extract (Log-Rank Test = 7.93; df = 4; P <0.094). This varied from 26.1 ± 2.4 d for methanol extract at 1,500 ppm, to 30.5 ± 1.9 d at 100 ppm treatment. The highest level of mortality was 44% at 1,500 ppm and the shortest was 36% at 100 ppm. The highest cumulative mortality was 52% in the 1,500 ppm treatment. Mean larval survival time of the aqueous extracts ranged from 26.3 ± 2.7 d in the 1,500 ppm treatment to 31.9 ± 1.4 d in the 100 ppm treatment. The highest mortality was 40% in the 1,500 ppm treatment and the lowest mortality was 36% in the 100 ppm treatment. The highest level of cumulative mortality was 48% in the 1,500 ppm treatment.

Figures

Fig. 2. Survival curves of Copitarsia decolora larvae fed on an artificial diet supplemented with extracts of Trichilia americana bark at 100, 500, 1,000, and 1,500 ppm: (a) hexane, (b) ethyl acetate.