Effects Of Kitchen Waste,Cu²⁺and Zn²⁺ On The Growth And Development Of Black Soldier Fly And The Migration Of Cu²⁺ And Zn²⁺

As diptera saprophagy resource insects,black soldier fly’larvae can consume a wide range of organic waste,including livestock manure and kitchen waste.For now,there is no feasibility study on taking kitchen waste as traditional breeding feed and investigate the influence on the growth and development of black soldier fly.In addition,with the intensive development of livestock breeding industry,some trace element such as Cu2+,Zn2+,are usually added in the poultry feed of livestock to promote the growth of animals.However,most of the heavy metals were excreted with livestock and poultry manure,which increased the security risks of applying those manure in agriculture.Meanwhile,there were few domestic studies about the translocation regularity of Cu2+and Zn2+during the process of the transforming of black soldier fly to livestock and poultry manure,as well as the influence from Cu2+and Zn2+to the growth and development of black soldier fly.This thesis aims at the above problems,and the results are as follows:1 Effects of the kitchen waste on the growth and development of black soldier flyUsing the kitchen waste as a colony feed and compare it with artificial diet to feed black soldier fly with four generations continuously,and study on the 15 parameters related to the growth and development of the black soldier fly.The results showed that the adult and the life cycle period of the black soldier fly fed with kitchen waste were respectively less than 1-3 days and 2-4 days from the artificial diet group.And there was no significant difference among the duration of larval,adult and life cycle of the fourth generation of the black soldier fly larvae fed with both kitchen waste and artificial diet.The pupae and the life cycle period of the two groups of the second generation were 2-3days longer and 7-9 days than the other three generations.The total number of clutches produced by adult black soldier fly fed with kitchen waste was 1.56 times higher than the artificial diet group.Meanwhile,the hatching rate difference between the eggs of the two groups was not significant,which were both between 84%and 88%.During the process of transforming kitchen waste,the length and weight of individual 5th instar larvae and the weight of individual larvae were significantly higher than those in the artificial diet group,and the same trend was showed among the pupae,and the length,width and weight of total and single pupae of kitchen waste group were also significantly higher than those belong to the artificial diet group.To the forth generation of black soldier fly,the eclosion rate of the two groups was both higher than 92%,and the difference was not significant.At the same time,during the feeding of black soldier fly with kitchen waste,the feed usage rate and conversion rate were both significantly higher than the artificial diet group.Those results indicate that the black soldier fly fed with kitchen waste grew normally,and even better than those in the artificial diet group in some qualities,so kitchen waste can replace the artificial feed in large-scale population propagation of the black soldier fly.2 Effects of different concentrations of Cu²⁺and Zn²⁺in artificial diet on the growth and development of black soldier fly larvaeIn this experiment,we fed black soldier fly larvae with artificial diet of different concentration of Cu²⁺or Zn²⁺to observe the effects from different concentration of Cu²⁺and Zn²⁺to the growth and development of black soldier fly larvae.The results showed that the black soldier fly can accept wider range of the concentration of Zn²⁺than that of Cu²⁺.In addition,the heavy metals could promote the growth and development of the larvae when the concentration of Cu²⁺and Zn²⁺was low,and when the concentration of Cu²⁺was at 160 mg/kg or the concentration of Zn²⁺was at 420 mg/kg,this enhancement was mostly obvious.However,Cu²⁺and Zn²⁺concentration was higher than that,there came the inhibitory effect on the growth and development of larvae.When the concentration of Cu²⁺was above 400 mg/kg or the concentration of Zn²⁺was above 700mg/kg,they had an obvious inhibition on the growth of black soldier fly larvae.When the concentration of Cu²⁺was above 4000 mg/kg or the concentration of Zn²⁺was above12700 mg/kg,the fresh weight of individual larva was decreased significantly or could not reach to 50%pupa,which influenced the reproduction of black soldier fly.When the concentration of Cu²⁺reached to 18225 mg/kg,or the concentration of Zn²⁺reached to20000 mg/kg,the black soldier fly larvae could hardly grow up,and could not reach the adult stage either.3 Study on the migration of Cu²⁺and Zn²⁺by black soldier fly larvaeWe studied on the transferring regularity of Cu²⁺and Zn²⁺after the transforming to three kinds of manure by black soldier fly.The result shows that most of the Cu²⁺and Zn²⁺in the raw manure were mainly transferred to the residue,and only less than 13%of Zn²⁺or 9%of Cu²⁺was absorbed into the body by the black soldier fly,while only less than 0.1%of Cu²⁺or Zn²⁺were transferred from raw manure to insect lipid.At the same time,when observing the transferring regularity of Cu²⁺and Zn²⁺in artificial diet,we found over 78.1%of Cu²⁺or Zn²⁺in the raw material were transferred to the corresponding residue,while only less than 10%of the Cu²⁺or 16%of the Zn²⁺in the raw material was absorbed by the larvae.And less than 0.1%of Cu²⁺and Zn²⁺in the raw materials were transferred to the insect lipid.However,the concentration of Zn²⁺in the skimmed insect powder was the highest and close to twice as much as that in the raw material,which was different from the transferring regularity of Cu²⁺and Zn²⁺in manure groups,it may be related to the bio-available form of heavy metals in manure and artificial diet.It is presumed that the bio-available form of heavy metals was higher in artificial diet added with Zn²⁺than that in manure,it helped Zn²⁺more easily absorbed by the black soldier fly easily,which led to the Zn²⁺concentration was higher in insect body after convert artificial diet was added with Zn²⁺.During the transferring of the black soldier fly to manure or artificial diet,the bio-accumulation factors Zn²⁺were all more than 1 and greater than that of Cu²⁺.The concentration of Zn²⁺in the larvae bodies were higher than that in raw material,and the black soldier fly larvae could accumulate Zn²⁺by transforming pig manure,chicken manure,and dairy manure,Cu²⁺can be accumulated by the transforming of black soldier fly to dairy manure,but was not accumulated obviously by transforming pig manure and chicken manure.After the transforming of black soldier fly to artificial diet added with Cu²⁺and Zn²⁺,Zn²⁺was accumulated,but Cu²⁺was not accumulated obviously.