| Nutritional indices of Tribolium castaneum (Herbst) (Col.: Tenebrionidae) affected by ethanolic extract from Euphorbia helioscopia |
| Paper ID : 1044-3IICE (R1) |
| Authors: |
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Roya Taghizadeh * Shahid Bakeri High Education Center of Miandoab, Urmia University, Urmia, Iran |
| Abstract: |
| The genus Euphorbia is the largest genus in the Euphorbiaceae family. All contain latex and have a medicinal importance. Ethanolic extract from aerial parts of Euphorbia helioscopia L. was evaluated for nutritional indices of the stored product insect, T. castaneum (Herbst). Relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI) were measured. Experiments were done in the dark condition, at 27±1°C and 60±5 % R.H. Several concentrations of extract (0.25, 0.5, 0.75, 1.0, 1.5 and 2.0%) with control were used evenly on the flour discs. After 72 h, nutritional indices of adults were calculated. One-way analysis of variance for comparing between different extract concentrations with Duncan's multiple range tests (P<0.05) were used to determine differences between means. Also correlations between measured factors were calculated. Results showed that nutritional indices were significantly affected as extract concentrations increased (P<0.05). The values of RGR, RCR and ECI were reduced significantly with increasing E. helioscopia extract concentration. It was shown that E. helioscopia extract had a strong effect on feeding behavior and growth of this pest. At concentration 0.5%, the RGR index is reduced about 50% (0.27 mg/mg/day) compared to the control (0.53 mg/mg/day). The treatment at higher concentration (2%) of E. helioscopia caused 91% (0.04 mg/mg/day) reduction of relative growth rate in adults. Although at concentration 2%, FDI was 69.78% but ECI was decreased compared to the control by 25.73%. These results showed that the ethanolic extract, in addition to the feeding deterrence, affect considerably in post-ingestive toxicity. There was significant positive correlations (P<0.05, r2>0.9) between RGR and RCR or ECI, also there was significant negative correlation between RGR and FDI. Generally, total mean values of RGR, RCR, ECI and FDI of this extract were 0.26 mg/mg/day, 0.56 mg/mg/day, 46.40% and 43.37%, respectively. Our findings suggests that using ethanolic extract from E. helioscopia could be significant method for reducing population of this pest. |
| Keywords: |
| Euphorbia helioscopia, Tribolium castaneum, stored product insect, feeding deterrence, extract |
| Status : Paper Accepted (Poster Presentation) |
