Honeybee winter failure and mortality are a big issue in korea, especially from 2021 to 2023. Traditionally, honeybee winter failure has been estimated as Approximately 10-20%. However, for last 2 years, we had more than 35% of winter failure which impacted not only beekeeping sectors but also agriculture and the whole society as well. Primary factor was ascribed as honeybee mite resistance development to conventional acaricudes. Coinhabitance of tropilaelaps mite in honeybee complicated the mite problem. Further threat of vespa hornets especially in fall season would exerbate the wintering condition. More important is that the more frequent abnormal weather condition in fall and winter season could affected the winter bee production and maintenance of honeybee overwintering physiology. On these situation, we also observed some diseases were associated to the death of bees.

Honeybee winter failure and mortality are a big issue in korea, especially from 2021 to 2023. Traditionally, honeybee winter failure has been estimated as Approximately 10-20%. However, for last 2 years, we had more than 35% of winter failure which impacted not only beekeeping sectors but also agriculture and the whole society as well. Primary factor was ascribed as honeybee mite resistance development to conventional acaricudes. Coinhabitance of tropilaelaps mite in honeybee complicated the mite problem. Further threat of vespa hornets especially in fall season would exerbate the wintering condition. More important is that the more frequent abnormal weather condition in fall and winter season could affected the winter bee production and maintenance of honeybee overwintering physiology. On these situation, we also observed some diseases were associated to the death of bees.

Modeling is one approach to better understanding the complex interaction in the abstracted and simplified forms. Here I present the interaction of honeybee, Apis mellifera and ectoparasitic mites of Varroa destructor and Tropilaelaps mercedesae. In the beginning, I provide the basic mechanism of ectoparasitic mite’s life cycle in association with the host insect life. Population behavior was analyzed as a single analytical population growth model. Then, since the carrying capacity of mite’s breeding resources are changing, I incorporated the damage function of mite to honeybee population. Incorporating the damage function into the honeybee-varroa interaction model provided more realistic behavior of both species. Simulation study showed that possible beneficial impact of hive-splitting on mite control. Also, varying the chemical spray timing and efficacies, the model simulation revealed that early spring acaricide treatment was essential for protection of honeybee from the varroa mites. At the last, this model has been expanded to include the other parasitic mite of Tropilaelaps mercedesae. For this, two species competition model was considered as well as incorporation of the host population behavior being added. Further discussion and call for collaboration were presented.

Varroa destructor and Tropilaelaps mercedesae mites are ectoparasitic to honey bee having similar life cycle and damage symptoms. Both invade into the last instar larval cell and reproduce during capped brood period of honey bee development. Female adult mites escape from the comb cell on the back of the emerging adult bee (phoretic period) and invade another cell for reproduction. Objective of this study was to study the effect of competitive interaction on each parasitic mite species population. We assessed population monitoring of host and parasitic mites. Honey bee population was monitored by approximating sealed brood and adult bees based on the coverage of the combs. Parasitic mites were monitored by detection technique like sugar shake, stick board, and sealed brood. This monitoring continued at weekly interval during 2008, 2014, and 2015. Additionally Invasion distribution of each species was checked. We calculated carrying capacity, population growth rate, and competition parameter from population monitoring data. Single parasitic mite, Varroa occurred and infestation increased continuously throughout the year in 2008. Co-occurrence of Varroa and Tropilaelaps in honey bee colonies was studied in 2014 and 2015. Carrying capacity was higher in single parasite infesting honeybee than parasites in co-occurrence. While using sugar method, carrying capacity of Varroa alone was found higher than in its co-occurrence with Tropilaelaps. Population growth rate of Varroa when tested alone was higher than its co-occurrence with Tropilaelaps in sugar method. Population growth rate of Varroa and Tropilaepas was higher in sticky method than sugar methods when they were tested in co-occurrence. Population growth rate is higher in Tropilaelaps (0.09) than Varroa (0.05) when both are tested in co-occurrence. We calculated competition parameter of Varroa and Tropilaelaps which was 1.9 and 0.53, respectively. Negative effect on regulation of carrying capacity and population growth rate is due to interspecies competition. Varroa population was higher than Tropilaelaps because there was high intraspecies competition among Tropilaelaps. Single Varroa or its co-occurrence with Tropilaelaps both can destroy honeybee colonies.

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.

Modeling the complex system often provide better understanding of the behavior of the system given that parameters for the modeling are appropriate. The honeybee mite, Varroa destructor Anderson and Trueman, is one of the most serious pests of honeybees in Korea. Even with vast amount of ecological information of this parasite and its host, Apis mellifera, in the world, limited information is available in Korean environment. This paper provides some basic framework of the varroa mite population dynamics modified from published works in western world to adapt to Korean beekeeping environment. Overall population growth rate was in agreement to those previous published. However the detail behavior was quite different mainly because of splitting honeybee colony during the summer season. Although this framework provide reasonable, logical theoretical linkage to varroa mite population growth, implementation of the results provided from this model is not appreciated mainly because this paper is intended to show the basic framework, not the simulated results. Thus, further incorporation of realistic parameters from honey bee and its parasites in Korean environment would provide better insight of the population behavior and management options. Also, research gaps which need to be filled are further discussed.