The Impact Of Copper,Cadmium,Lead And Selenium On Individual And The Whole Colony Health Of Apis Mellifera L.(Hymenoptera:Apidae)

The honey bee Apis mellifera L.?Hymenoptera:Apidae?is one of the most important pollinators around the world,which plays an essential role in plant pollination and crop production.Threatening the development and whole colony health of A.mellifera,heavy metal pollution becomes more and more severe due to industrial production and human activities.Besides,the colony collapse disorder?CCD?around the world has arisen people's attention on protecting A.mellifera colony in the background of environmental pollution.Thus,to study the impact of common heavy metals on the development,reproduction and the whole colony health of A.mellifera,as well as the biotrasnfer from plants to honey bees and the accumulation,and then to provide baseline data of threats caused by heavy metals from the environment to A.mellifera,and in the mean time to explore the theoretical basis on A.mellifera colony protection,we studied the impacts from several aspects,1)A.mellifera larvae and foragers individual level,2)whole colony level and 3)the interactions between radish Raphanus sativus L.and A.mellifera.Four tests were carried out to study the negative impacts of common heavy metals copper?Cu?,cadmium?Cd?and lead?Pb?,and metalloid material selenium?Se?on A.mellifera in-depth.1)The biology impacts of Cd,Cu or Pb on A.mellifera larvae and foragers;2)The impact on A.mellifera larvae and foragers when Cd and Cu co-occur;3)The influence of Cd,Cu,Pb and Se on A.mellifera whole colony health;4)The bioaccumulation of Cd,Cu and Pb in plants and the biotransfer to A.mellifera.To be specific,we conducted the chronic toxicity assay on larvae and acute toxicity assay on foragers to test the heavy metal effects.Oven digestion and inductively coupled plasma emission spectrometry?ICP-OES?were carried out for testing metal accumulation in A.mellifera and R.sativus flowers.We found that Cd,Cu and Pb showed negative effects on A.mellifera growth and development.Cd,Cu and Pb can accumulate in R.sativus flowers and transfer to pollinators by food chain.Cd,Cu,Pb and Se were not conducive to the sustainable development of A.mellifera colony.Also,Cd and Cu showed synergistic effects on A.mellifera when they co-occurred in the ratio of 1 to 1,indicating more serious influences on honey bee.Specifically,the LC_50s of Cd,Cu and Pb on foragers were 78 mg/L,72 mg/L and 345 mg/L,respectively.And for larvae,the LC_50s were 0.275 mg/L,6.970 mg/L and 1.120 mg/L,respectively.The mixture of Cd and Cu had a LC₅₀ of 1.575 mg/L for larvae and it was 72.3mg/L for foragers.Individual treatment groups of Cd,Cu or Pb as well as Cd and Cu hybrid reduced the relative growth index,prolonged development period,increased mortality of foragers and larvae,and decreased foragers appetite on 50%sucrose.Honey bee foragers and larvae accumulated significant amount of Cd,Cu and Pb in a dose dependent manner.The sucrose response threshold of foragers decreased,indicating that the heavy metal stress brought down foragers'choice ability on food.In addition,for the whole colony health,the number of dead pupae increased,the activity of foragers and wax production in Cu treatment groups decreased,and the queen,workers inside the hive,alive foragers,dead foragers,pupae as well as honey accumulated significant amount of metals in Cd,Cu,Pb and Se treatment groups.The plant reproductive growth strategy changed,the mean number of radish flowers decreased,the metal accumulation in radish flowers increased and A.mellifera accumulated more heavy metals in their bodies from Cd,Cu and Pb treatment groups compared to control groups.However,there was no significant difference for the bee visitation rate.In brief,our research systematically studied the influence of common heavy metals found in the environment on the individual,the whole colony and the passive accumulation of metals by foraging on metal contaminated nectariferous plants to A.mellifera.This research provided baseline data for the impacts of heavy metals,Cd,Cu and Pb,and metalloid material Se,on A.mellifera from the perspective of quantitative ecology and toxicology.At the same time,we established the research pattern studing the impact of heavy metals on resource insects.This research not only provided theoretical support for colony protection,but also benefited the sustainable development of honey bee colonies.