In Vespa velutina, although no parasites or parasitoids have been found as natural enemies, strepsipteran parasites were first discovered in 11 workers in Andong in 2020. Identification using the DNA barcode method along with the morphological characters, identified them as Xenos moutoni and X. oxyodontes. These were all males (except for one parasite whose appearance was not identified), and consisted of four larvae and seven pupae. This is the first recorded strepsipteran parasites in Korea, Japan, and Europe, invaded by V. velutina. A Strepsipteran parasite is prevalent in Vespa species, but reports on the host is lacking in Korea. Although it was not possible to determine the exact infection rate of the strepsipteran parasites in this study, it seems that the parasite of V. velutina has already progressed in the southern region due to the geographical characteristics of Andong, located in the central region of Korea. In particular, stylopized workers do not work in the nest, which negatively affects nest development, and reproductive individuals (male and new queen) do not mate, which negatively affects the formation of new colonies in the following year. Nevertheless, the control effect is likely to be minor due to the high reproductive rate and compensatory effect of social wasps.

외래종 등검은말벌은 양봉농가에 막대한 경제적 피해를 입히는 대표적인 양봉 해충으로 알려져 있다. 본 연구 에서는 경북 의성 및 안동 일대에서 양봉장 주변 2km 지점 내에 발생하는 등검은말벌의 벌집 밀도에 대해 조사하 였다. 조사기간은 2023년 12월 1-20일까지 조사되었으며 육안, 망원경 및 드론을 통해 가능한 한 모든 지점을 조사하였다. 이번 조사에서 발견된 총 등검은말벌 벌집 수는 133개로 조사되었다. 그 중 의성에 위치한 5곳의 양봉장에서는 총 67개로 평균 13.4개, 안동에 위치한 5곳의 양봉장에서는 총 66개로 평균 13.2개로 나타나 두 지역이 거의 유사한 경향을 나타내었다. 10개의 양봉장 중 안동 안기동 일대 양봉장에서 최대 26개의 등검은말벌 벌집이 발견되었으며 의성 단촌 일대 양봉장에서는 4개만이 발견되어 큰 격차를 보였다. 양봉장에 피해는 주는 등검은말벌의 출현 비율은 주변 벌집 밀도에 영향을 직접적으로 받고 있기 때문에 정확한 밀도 및 거리 등을 토대로 적절한 방제 전략이 필요할 것으로 보인다.

2003년 국내에 침입한 외래종 등검은말벌(Vespa velutina nigrithorax)은 현재 남한 전체에 확산된 상태이며 이들로 인한 사회 경제적 피해는 지속적으로 증가하고 있다. 따라서 이들을 방제하기 위한 다양한 방법이 시도되 고 있으나 그 효과는 대부분 미미한 상황이다. 그러나 최근 생물학적 방제에 대한 관심이 집중되는 상황에서 외래종 등검은말벌에 대한 새로운 포식자 2종이 발견되어 이를 보고하고자 한다. 2023년 8월 11일 전북 무주군 적상면 일대에서 오소리 배설물 조사 중 배설물 속에 다량의 말벌 사체가 발견되었고 분석 결과 10여개체의 등검 은말벌로 나타났다. 이는 일반적으로 땅벌류를 주로 포식하는 오소리가 대형 말벌류를 포식하는 첫 기록이다. 또한 2023년 12월 10일 안동 일대에서 등검은말벌 벌집 조사를 하던 중 벌집에 10여 마리의 직박구리가 벌집 외피를 깨고 내부에 있는 애벌레와 성충들을 포식하는 장면이 관찰되면서 벌매에 이어 새로운 조류 포식자를 기록한다.

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.