Due to their environmental and economical consequences, invasive species have become a major concern worldwide. Among them, the yellow-legged hornet, Vespa velutina, is a keen hunter of domestic honeybees. They use olfactory cues from the prey to assess food information. In this study, we investigated the attraction behavior of V. velutina to honeybee pheromone under outdoor conditions. Nine honeybee pheromones were tested and compared in order to find the best attractant. When testing specific compounds, the honeybee queen pheromone, homovanillyl alcohol, proved highly attractive.

We sequenced the complete mitochondrial genome (mitogenome) of Vespa velutina nigrithorax and V. ducalis (Hymenoptera: Vespidae). The genomes were 16,475-bp and 15,779-bp long and contained typical sets of genes. The V. velutina and V. ducalis A+T-rich region was 132-bp long and 166-bp long and was the shortest of all sequenced Vespoidea genomes. Start and stop codons in several Vespa species—including V. velutina and V. ducalis—were diversified, despite these species belonging to the same genus. In comparison with the ancestral mitogenomes, Vespa mitogenomes showed substantial gene rearrangement; however, we detected no gene rearrangement among Vespa species. We conducted phylogenetic reconstruction based on concatenated sequences of 13 PCGs and two rRNAs in available species of Vespoidea—22 species in six subfamilies in two families (Vespidae and Formicidae). The Bayesian inference and maximum likelihood (ML) methods revealed that each family formed strong monophyletic groups.

Vespa velutina nigrithorax prey on various insect and especially hunts domestic honeybees, such as the European honeybee, Apis melifera. For that reason, V. velutina predation has a direct economic impact on apiculture. In particular V. velutina queens are able to establish of new colonies, so they are suitable for V. velutina management. This study was conducted to investigate the attractant of V. velutina Queen. Four traps were tested and combined attractant such as honeybee comb extraction, honeybee extraction, pollen, rice wine and sugar syrup for attraction efficacy. We was able to observe V. velutina Queen in late April to May. And Honeybee extraction, rice wine and sugar syrup baits (5 : 3 : 2) was the best combination for trapping queen on spring.

The highabundance and impact on honeybees of the Asian hornet Vespa velutina var. nigrithorax have caused great concern among European public authorities and beekeepers. The species was reported for the first time in France in 2005 and spread out across 66 European districts (ca. 360 000 km 2 ) within 7 years (INPN, 2012; Rome et al., 2013). Its arrival was reported in 2010 in Northern Spain, in 2011 in Portugal and Belgium and in 2013 in Italy. Its wider expansion in Europe is soon to be expected. We discuss here the advances of the collaborative research project initiated in 2008 in France. 1. The potential invasion risk of the species was assessed using modeling tools of climatic suitability (Villemant et al., 2011, Barbet-Massin et al., 2013). Interestingly, the potential distribution of V. v. nigrithorax matches the current distribution of another invasive social wasp, the German yellow jacket, Vespula germanica (Beggs et al., 2011). 2. Apartfrom reported damages on hives, little is known on the biology of V. velutina throughout its native Asian range. In the invaded range, the impact of V. v. nigrithorax on the diversity and biomass of the invertebrate fauna is under study. Preliminary results reported a diversified diet varying among seasons and habitat types. 3. The genetic variability between individuals of V. v. nigrithorax from France and Asia was assessed in order to describe the history of its invasion. The analysis has evidenced a low variability among the invasive population, which indicates a single introduction of one or more queens. The sampling of specimens in France and in the area of origin has been extended to confirm this hypothesis and the most probable area of origin (Arca, 2012). Given the potential economic and biological impact of V. v. nigrithorax, a better understanding of its invasion dynamics is necessary to predict regions at risk, hence to help with planning dedicated control measures, a prerequisite for replacing the reactive nature of current solutions with a proactive, predictive approach.

Invasive hornet Vespa velutina nigrithorax, which was found at Yeongdo, Busan for the first time in 2003, has been spreading to whole area of Gyeongnam and even to some southern parts of Gyeongbuk for last ten years, causing lots of damage. Urban area of Busan already showed dominant distribution of V. v. nigrithorax marking more than 90% of emergence rate by its spread, while in forest area, its rate had not been so high due to its competition with native Vespa species. However, recently dominance of this species was detected continuously in some forests in Busan. Thus, this study conducted a survey of emergence rate of V. v. nigrithorax at Mt. Bongraesan, Yeongdo-gu, Busan where it was discovered for the first time and also conducted observation of its behaviors related with competition for prey in order to understand its ecological niche relation with native Vespa species. Consequently, 4,560 individuals were collected in total out of main five species of Vespa at Mt. Bongraesan. Of these, V. mandarinia made up 8.7% with 397, V. crabro flavofasciata 21.2% with 965, V. analis parallela 23% with 1,048, V. simillima simillima 0.6% with 27, while V. v. nigrithorax made up 46.6% with 2,123, demonstrating the aspect of the most dominant emergence of V. v. nigrithorax. On the other hand, ecological niche due to competition for prey between V. v. nigrithorax and native Vespa species was revealed in the order of V. mandarinia >> V. crabro flavofasciata > V. analis parallela ≥ V. v. nigrithorax, telling ecological niche of V. v. nigrithorax was relatively low compared to native Vespa species, despite its dominant emergence. This background may explain why in forest area, V. v. nigrithorax had a limited spread and dominance compared to urban area of less competition among Vespa species. On the other hand, V. v. nigrithorax seems to have advantage in catching small insects due to developed agility with its smaller size than other Vespa species, and its rapid spread and adaptation in the local environment may be mainly attributable to its far more number of individuals than native Vespa species and consequent high reproductive rates and diversity of nesting site.

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.