Study On Natural Stripe, Distribution And Parasitical Characteristics Of Varroa Destructor In China

Varroa destructor, one of the ectoparasitic mites that belong to Acari Varroidae Varroa, highly-specializedly parasitizes on adult honey bee and larva and feeds on haemolymph of it's host. It has spreaded almost all over the world. Almost 100% colonies of Apis mellifera were infected by Varroa destructor. The colonies could be destroyed in 1-2 years without Varroa destructor controled. Varroa destructor has been the most harmful pest of beekeeping in the world.To control the mite effectively, its taxonomic status, geography distribution and biological characteristics should be clarified first. Based on the previous research work, we further investigated the natural species composing, distribution and difference on parasitical characteristics of Varroa destructor in China. Results are as follows.Sequences and AFLP analysis have been done on 16 Varroa destructor samples from Apis cerana colonies in 10 provinces of China. The mites from south-east of China Fujian,Jiangxi, Zhejiang,Hunan and Anhui provinces belong to Korea genotype of V.destructor. The mites from Hainan province belong to Korea genotype of V.destructor too.The mites from Guizhou province belong to China 1 genotype of V.destructor. The mites from Sichuan and Gansu provinces belong to China 2 genotype of V.destructor. The mites from Guangxi province belong to an new genotype that is found for the first time.if Sequences and AFLP analysis have been done on 16 Varroa destructor samples from Apis mellifera colonies in 8 provinces of China. The most of samples from Apis mellifera belong to Korea genotype of V.destructor. Among 3 Varroa destructor samples from Jiangxi province, one was found to be a China 2 genotype of V.destructor and the other 2 mites in same hive were Korea genotype. China 2 genotype which was not found on Apis mellifera before is a special species that parasitizs on Apis cerana.. The similar new genotype mite was also found in Apis cerana in Guangxi province. Among 4 mites in the same hive, one mite was new China 2 genetype, two mites belonging to China 1 geontype. The result showed that Apis mellifera could take Varroa mites from Apis cerana.if Combined with previous work, the distribution of Varroa destructor genotypes from Apis mellifera and Apis cerana was mapped using the software of geographic analysis. Based on geographic environment and history event, we can explain why V.destructor was firstly found on Apis mellifera in Zhejiang province and the Korea genotype of V.destructor traceable in Zhejiang or Anhui province could be predicted. We found that China 2 genotype has a strong adaptability and is easily to spread. So it may have potential danger to beekeeping. if The sequences of 4 V.destructor samples mtDNA 16SrRNA gene fragment were compared. The result showed that the sequences were identical with only a little different from the data of GenBank. We speculate that this gene has a slower speed of evolution than that of CO1 gene. Thus, it could be used to identify the organism between generic,but not to identify the organism between species and genotype.We compared the concentration of free amino acid and microelement in haemolymph of larvae (Apis cerana and Apis mellifera ;drone and worker bee) that just capped. The results showed that the concentration of free amino acid in haemolymph of Apis cerana worker larva was higher than that in the other 3 type larva which is contrary to the host attraction of V.destructor. The concentration of mineral element about reproduction in haemolymph of Apis cerana drone larva was higher than that in the other 3 type larva, which is related to the host attraction of V.destructor. It is speculated that the diversity of the component in haemolymph had a correlation to the tolerance in A. cerana to Varroa destructor.