Studies On The Microencapsulated Artificial Diet Prescription And Application Of Orius Sauteri (Hemiptera: Anthocoridae)

The flower bug Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important predatory natural enemy with a broad die menu. As a independent biological control agent, O. sauteri was imported to the major regions of agricultural production.The present experiments focused on the key section in massive reproduction of O. sauteri, artificial diets. And we introduced the microencapsulation technique into the procedure of artificial diet production. A series experiments to investigate the optimal compositions of microencapsulation of artificial diet were undertook in the laboratory. We relied on the results of optimal microencapsulated artificial diet to confirm the optimal prescription of artificial diet compositions which were targeted on the different biological and physiological characteristics. Rearing by this series artificial diet microcapsules, we compared the differences among these microcapsules in respiration, locomotors abilities. Consequently, we also compared the predatory capacity of O. sauteri which fed by this series artificial diet with different Megoura japonica density and to fit the formula of Holling II model.Based on the original artificial diet prescription, present experiments promoted the artificial diet model by microencapsulation technology. We confirmed the influences of sodium alginate, chitosan and the ratio of core material to wall-forming material to yield ratio, embedding ratio, moist ratio and sensory evaluation level of artificial diet microcapsules by orthogonal experiments. The results indicated that the the influential order of ingredients to yield ratio successively was ratio of core material to wall-forming material > sodium alginate > chitosan; the optimum proportion was sodium alginate 1.0%, chitosan 0.6% and ratio of core material to wall-forming material was 1:3. And the influential order of ingredients to embedding ratio successively was chitosan > sodium alginate > ratio of core material to wall-forming material; so the optimum proportion was sodium alginate 1.0%, chitosan 0.8% and ratio of core material to wall-forming material was 1:1. Furthermore, the sodium alginate influenced the moist ratio mostly and chitosan in second place. When the proportions were sodium alginate 2.0%, chitosan 0.6% and ratio of core material to wall-forming material was 1:2, the moist ratio of artificial diet microcapsule was highest. We observed similar tendency in sensory evaluation and the related most optimum prescription was sodium alginate 2.0%, chitosan 0.6% and ratio of core material to wall-forming material was 1:3. By the comparison of development status between the O. sauteri fed on the artificial diet microcapsule with most optimum prescription and CK (fed on T. cinnabarinus), we only observed significant differences in 1st and 2nd instar development duration. And O. sauteri female adult showed significant shorter life span in artificial diet treatment than CK group. Whereas, there wasn't significant difference of emergence ratio between two treatments. O. sauteri showed significant lower in oviposition duration. fecundity and viable ratio by feeding on artificial diet microcapsules although we did not observed any differences in pre-oviposition entirely. As intensive analysis of artificial diet effects, the respiratory quotient of O. sauteri fed on artificial diet was lower than CK significantly. We observed converse tendency in comparison of average creeping speed and the results indicated there was a slenderd correlation between creeping speed variation and locomotor duration.We confirmed the optimal prescription of artificial diet based on the previous results with microencapsulation technique. The composition of artificial diet included: Vitellus (A), Tussah pupa (B), Sucrose (C), Honey (D), Farina of rape (E), Sinkaline (F). We confirmed the optimal formula which was consisted with above materials with orthogonal experiments. The results showed the artificial diets treatments influenced the development and reproductive ability significantly. After analyzed by ANOVA and rang analysis, the order of effects of compositions to development duration of total nymph stage was: tussah pupa > vitellus > sinkaline > sucrose > honey > rape farina, the experiment group with the ingredients composited as vitellus 30 g, tussah pupa 40 g, sucrose 10g, honey 15 g, sinkaline 20 g and without any rape farina was the most optimum combination; the order of effects of compositions to survival ration was: honey > sucrose > rape farina > sinkaline > tussah pupae > vitellus, We also confirmed the optimum combination of ingredients was the vitellus 30 g, tussah pupa 50 g, sucrose 10 g, honey 15 g, sinkaline 10 g and rape farina 10 g; the order of effects of compositions to oviposition duration was: honey > sucrose > rape farina > vitellus > sinkaline > tussah pupa, the optimum combination experimental group was recorded as tussah pupa 50 g, sucrose 10 g, honey 15 g, rape farina 10 g and without any vitellus or sinkaline 1; the order of effects of compositions to fecundity was: vitellus > honey > rape farina > tussah pupa > sucrose > sinkaline, the optimum combination experimental group was recorded as vitellus 40 g, tussah pupa 50 g, sucrose 10 g, honey 5 g, rape farina 10 g and without any sinkaline; the order of effects of compositions to viable ratio was similar to fecundity except the proportion of honey and sinkaline were 10 g and 10 g respectively. We also compared the respiration and locomotor ability of female adults which were fed by this series artificial diet microcapsules. The results indicated that all of respiratory quotient, metabolic ratio and average creeping speed were influenced by artificial diet treatments dignificantly.We used the female adults which were fed by the different artificial diet microcapsules just as previous part to observed the predatory capacity of O. sauteri to M. japonica in different prey densities. We fitted the results to Holling II model formula and calculated the search effect index with the parameters which were generated by the formulas. The results showed that different artificial diet microcapsules effected the prey consumed amount significantly in different prey densities. Similarly, we also observed the significant differences of prey consumed amount among all artificial diet microcapsules in same prey density. All artificial diet treatments showed significantly higher than CK group. The predatory variations of all artificial diet treatments were fitted in Holling II model. The a'was highest in MS group and the duration of dealing was highest in CK. We found the highest theoretical prey consumed amount in MF treatment as 47.6。The search effect index was increased with prey densities linearly. And we found the most variance in MS treatment and the smallest in CK.