Biological invasion is becoming more important disturbance factor to the structure and function of ecosystem as well as to the bio-industry such as apiculture. Since the invasion of the yellow-legged hornet, Vespa velutina nigrithorax Buysson, 1905 into Busan port, the southeastern part of Korea in 2003, gradual spread of the hornet was observed. The rate of spread was estimated as 12.4 Km/yr, which was 5.6 times slower than that from France, 67.3 Km/yr. The diffusion coefficient (D) is still in increasing phase, implying the greater risk of spread. The Korean population was homologous to Zhejiang population of China implying the possible invasion source. It has a great potential to harm the Korean beekeeping industry and the ecosystem through the competition with the similar guild, the other 10 spcies of Vespa in Korea. Among those, smaller sized hornets such as Vespa analis or V. simillima simillam seemed under serious impact. Community structure of Vespa was different before and after the invasion. After V. velutina invasion, the survey on 2010 from Gyeongnam province showed 67% of V. velutina and reduced proportion of the smaller size hornets such as V. analis, V. crabro and V. simillima simillima compared to the bigger sized hornets such as V. mandarinia or V. ducalis. Also because of the nesting urban area, public education and involvement are requested for protection against the hornet’s aggresiveness and also for monitoring the distribution and population expansion. Further research and public network would mitigate the potential risks.

Toxic Mastoparan B(MP-B) which is purified from the venom of the hornet Vespa basalis is a cationic amphiphilic tetradecapeptide. MP-B and its Ala-substituted analogues were synthesized by solid phase method and the toxic peptide-membrane interactions were examined by circular dichroism(CD) spectra, fluorescence spectra, and leakage abilities in phospholipid membranes. In the presence of phospholipid vesicles, synthetic MP-B and its analogues formed amphiphilic α-helical structures, but in the buffer solution, those exhibited random coil conformation as measured by CD. Fluorescence spectra of MP-13 and its analogues which indicated the binding affinity of peptide on phospholipid vesicles showed that the replacement of Lys at position 2 and 11 with Ala caused a remarkable effect in the blue shift and that at position 2, in the leakage ability of the peptide.