| Orius sauteri, (Hemiptera: Anthocoridae) is a common polyphagous predator on vegetables, fruit trees and crops in China. Although a lot of researchs on its rearing techniques in laboratory have been carried out in China, still no proven rearing technology is available, which makes it difficult to be used as biocontrol agent in a large scale now. Aimed to reveal effects of preys to O. sauteri, the nymph developmental period, survival, adult longevity and fecundity of O. sauteri fed on fruit fly nymph (Drosophila melanogaster), western flower thrip (Frankliniella occidentalis) and soybean aphid (Aphis craccivora) was compared, and the effect of two different preys (soybean aphid and western flower thrip) on predation of O. sauteri was studied. The effect of high temperature shock on the survival rate and fecundity of O. sauteri.was also researched.1 Evaluation of three diets of O. sauteriNymphal developmental period, survival, adult longevity and fecundity of O. sauteri fed on fruit fly nymph (D. melanogaster), western flower thrip (Frankliniella occidentalis) and soybean aphid (Aphis craccivora) were compared under condition of 25°C and 16L:8D. There were no significant differences in nymph survival rate fed on the three diets (89.50%, 88.17% and 82.56%, respectively). Nymph stage and adult longevity fed on D. melanogaster nymph (12.36 days and 18.50 days) and F.ccidentalis (12.19 days and 18.01 days) were significantly longer than those fed on A. craccivora (11.11 days and 15.23 days). The fecundities fed on D. melanogaster nymph (89.58 eggs/female) and F. occidentalis (95.96 eggs/female) were also significantly higher than those fed on A. craccivora (59.07eggs/female). The results indicated that D. melanogaster nymph have similar function as O. sauteri's preference diet with western flower thrip and appears to be a suitable diet for mass rearing of O. sauteri .2 Effect of prey breeding experience on predation of O. sauteriThe predation and prey preference of O. sauteri adults, which were fed on A. craccivora and F. occidentalis respectively, were studied. Results showed that the predation rates of O. sauteri fed on either A. craccivora or F. occidentalis for three generations all increased with of the prey density. The pradation rates for A. craccivora and F. occidentalis of O. sauteri fed with F. occidentalis for three generations were 16.20 and 20.60 at 30 preys per petri dish, respectively. Meanwhile the predation rates for A. craccivora and F. occidentalis of O. sauteri fed with A.craccivora for three generations were 19.20 and 16.20 at 30 preys per petri dish, respectively. The result indicated that O. sauteri had a preference to the diets fed on for a long-term, which surpported us to rear O. sauteri by changing its diets to control some sepcifical pests.3 Effects of high temperature shocks on survival and fecundity of O. sauteriThe survival rate, pre-oviposition period, fecundity and longevity of O. sauteri adults were studied at 39°C, 41°C and43°C for 1h. The experimental results showed that the survival rates of O.sauteri adults decreased from 94.44% to 68.89% at the temperature from 39°C to 41°C. Pre-oviposition period of O.sauteri female increased with the high temperature shock. The Pre-oviposition period at 25°C was 2.56d, and got to 4.11d at 41°C for 1h. Number of eggs per O.sauteri female decreased significantly from 60.44 eggs at 25°C to 24.10 eggs at 39°C for 1h, and 13.78 eggs at 41°C for 1h. The life time of O. sauteri adults decreased with the high temperature shock. The life time of female adult was 15.33 d at 25°C, and 8.11d at 43°C for 1h.The results indicated that the high temperature exposure even for a short time had the adverse impacts on fecundity of O. sauteri.
|
PDF Full Text Request