| The predatory stink bug,Eocanthecona furcellata(Wolff)(Heteroptera:Pentatomidae),an important predatory insect,has a wide application prospect in the biological control of agricultural pests.However,the feasibility of predatory stink bug as a kind of important biological agents for controlling pests in the field is mainly depend on its mass rearing.In order to explore the relationship between the nutrient composition of the insect diets and the growth and reproduction of E.furcellata,the influence of two kinds of insect diets on the growth and reproduction of E.furcellata were studied by continuously feeding stink bugs 3 generations with larvae of Tenebrio molitor(L.)and Spodoptera frugiperda(J.E.Smith).The nutrient composition of two kinds of insect diets was analyzed.The concentration of vitellogenin in the female adults of E.furcellata which were fed with T.molitor and S.frugiperda was analyzed by the enzyme-linked immunosorbent assay.This study is to provide theoretical basis for the subsequent research on the composition and proportion of the artificial diets.The main research results are as follows:1.The total developmental duration of the first,second and third generation nymph of E.furcellata which were fed with T.molitor were 19.94,22.85,19.75 days and that of E.furcellata fed with S.frugiperda were 17.18,17.77,19.12 days,respectively.The total developmental duration of nymphs fed with S.frugiperda was shorter than which fed with T.molitor.The result of two kinds of treatment was significantly different.The survival rate of the first,second and third generation nymph of E.furcellata fed with T.molitor were69.05%,27.05%,52.74% and that of E.furcellata fed with S.frugiperda were 67.71%,69.25%,39.05%,respectively.The result of two treatments was similar and no significant difference.The pre-oviposition period of the first,second and third generation of female adults which fed with T.molitor were 19.11,18.00 and 18.38 days,respectively.The reproduction of female adults was 16.06,15.61 and 51.80,respectively.The net proliferation rate was 3.69,1.33 and 13.00,respectively.The pre-oviposition period of the first,second and third generation of female adults of E.furcellata which fed with S.frugiperda were 17.21,8.31 and 9.38 days,the reproduction was 215.22,226.83 and 201,net proliferation rate was 30.40,30.37 and 16.47,respectively.The pre-oviposition periods of E.furcellata fed with S.frugiperda was shorter than which fed with T.molitor.The oviposition amount of the E.furcellata fed with S.frugiperda was larger and significantly different from which fed with T.molitor.The net proliferation rate of the E.furcellata fed with S.frugiperda was higher than which fed with T.molitor.There was no significant difference in egg developmental duration and hatching rate of the offspring of E.furcellata fed with T.molitor and S.frugiperda.2.The nutritional composition,amino acid content and fatty acid content of the larvae of T.molitor and S.frugiperda were determined and compared by the national standard methods.The results showed that the content of crude protein was 49.75% and 38.86%,the content of crude fat was 31.21% and 20.45%,the content of glucose was 4.46μmol/g and1.97μmol/g,and the content of trehalose was 7.60 mg/g and 6.87 mg/g.The content of moisture was 4.49% and 4.47%,and the content of ash was 3.61% and 3.56%.The content of crude protein,crude fat,glucose and trehalose of T.molitor were higher,but the contents of moisture and ash were similar in the two insect diets.The total amino acids(TAA)and essential amino acids(EAA)of T.molitor were 142.87mg/g and 64.88mg/g,the EAA/TAA value was 45.41%.The total amino acids(TAA)and essential amino acids(EAA)of the S.f rugiperda were 115.42mg/g and 75.61mg/g,the EAA/TAA value was 65.51%,indicating that the amino acid ratio of T.molitor and S.frugiperda were reasonable.The content of methionine in S.frugiperda was 57.29 mg/g,which was significantly higher than that in T.molitor.Nearly 90% of fatty acids in T.molitor were C16-C18 fatty acids,of which unsaturated fatty acids were dominant,oleic acid accounts for about 50% and linoleic acid accounts about 25%.The fatty acid content of C16-C18 in S.frugiperda was similar to that of T.molitor,but the content of oleic acid and linoleic acid were opposite,and the content of saturated fatty acid was generally higher than that of T.molitor.3.The content of vitellogenin in the hemolymph of the first and third generation female adults of E.furcellata were determined.The results showed that the vitellogenin concentrations of E.furcellata fed with T.molitor were 220.3324 and 212.9721 μg/m L,fed with S.frugiperda were 188.2148 and 154.7590 μg/m L.The concentration of vitellogenin in haemolymph of female adults of E.furcellata fed with T.molitor was significantly higher than which fed with S.frugiperda.In conclusion,the growth duration of successive generations of E.furcellata fed with S.frugiperda is significantly shortened,and the egg production is significantly increased,and the net proliferation rate is also much higher than which fed with T.molitor.The contents of methionine and fatty acid,which are beneficial for the growth,development and reproduction of predator,are higher than those of T.molitor.The comparison of vitellogenin concentrations between the two insect diets showed that feeding on S.frugiperda could promote the transformation of vitellogenin in the female adults,which was beneficial to the reproduction of E.furcellata.The results showed that S.frugiperda was an attractive and suitable diet for E.furcellata,which could be used as a reference for the formulation of artificial diet. |
PDF Full Text Request