The effects of tomato fruit extracts on Habrobracon hebetor Say (Hym.: Braconidae)
Paper ID : 1196-3IICE (R2)
Authors:
Manizheh ------ Jamshidi *1, Samira ------ Delgavan2, Mohammad ------- Jafarlou3
1Depends. Enthomology
2Post graduated
3researcher
Abstract:
Due to limited application of chemical pesticides on vegetable,s a great effort is directed toward use of biological and cultural control strategies. Studies have revealed that some plant extracts may hinder the activity of insects in their natural habitat. It was shown recently that tomato fruit extract rendered antimicrobial and pesticides properties in the presence of phenolic compounds occurring throughout the plant. That is why the amount of the pest damages to tomato fruit is considerably lower compared to that on leaves. Such finding of insecticidal performance of fruit extracts has made tomato an attractive system against vegetables pest. On the other hand, this property may play as a double edge knife as there are very efficient natural enemies active on tomato pests, simultaneously. Therefore, a study was conducted to evaluate the effect of acetone and methanol tomato fruit extracts on the ectoparasitoid wasp, Habrobracon hebetor Say, as an important biological control agent of the tomato fruit worm, Helicoverpa armigera (Hub) at 26 ± 1°C, 60 ± 5 % RH and 16:8 h (L: D). The results showed that the toxicity of methanol extract to B. hebetor was significantly higher compared with that of acetone extract. The value of gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (r) and mean generation time (T) in acetone and methanol extracts were 22.32 and 45.04 offspring, 10.18 and 14.46 offspring, 0.15 and 0.16 day-1 and 15.40, 16.33 days, respectively. In conclusion, our results detected that tomato fruit extracts could affect H. hebetor life parameters significantly. Further investigations are required to find out the long term effects of plant extracts on natural enemies whether tolerating or a fitness trade off evolved.
Keywords:
Tomato fruit extract, Habrobracon hebetor, Life table, Biological control.
Status : Paper Accepted (Poster Presentation)