The invasive alien species (IAS) Vespa bicolor is the first reported hornet that has established in Taiwan and is concerning as they prey on honeybee Apis mellifera, which leads to colony losses and public concerns. Thus, the aim of this study was to assess the current status of V. bicolor abundance, dispersal, and impact and to trace the origins of Taiwan’s V. bicolor population. Our studies took place in five areas in northern to central Taiwan. We used mtDNA in the phylogenetic analyses. Field survey and ecological niche modeling (ENM) were used to understand the origins and current range of the invasive species. Two main subgroups of V. bicolor in the phylogenetic tree were found, and a clade with short branch lengths in Southeastern China and Taiwan formed a subgroup, which shows that the Taiwan population may have invaded from a single event. Evidence shows that V. bicolor is not a severe pest to honeybees in the study area; however, using ENM, we predict the rapid dispersion of this species to the cooler and hilly mountain areas of Taiwan. The management of V. bicolor should also involve considering it a local pest to reduce loss by beekeepers and public fear in Taiwan. Our findings highlight how the government, beekeepers, and researchers alike should be aware of the implications of V. bicolor’s rapid range expansion in Taiwan, or in other countries.

The invasion of Apis florea in Taiwan was first recorded in 2017. The deformed wing virus (DWV) has been identified as a common bee virus in apiculture around the world. Ectoparasitic mites are the main DWV vector for horizontal transmission. However, there are few studies about the ectoparasitic mite of Euvarroa sinhai, which has been found in A. florea. In this study, the prevalence of DWV among four hosts, including A. florea, Apis mellifera, E. sinhai, and Varroa destructor, was determined. The results showed that a high DWV-A prevalence rate in A. florea, ranging from 69.2% to 94.4%, was detected. Additionally, the genome of DWV isolates was sequenced and subjected to phylogenetic analysis based on the complete polyprotein sequence. Furthermore, isolates from A. florea and E. sinhai both formed a monophyletic group for the DWV-A lineage, and the sequence identity was 88% between the isolates and DWV-A reference strains. As noted above, two isolates could be the novel DWV strain. It cannot be excluded that novel DWV strains could pose an indirect threat to sympatric species, such as A. mellifera and Apis cerana.

The Adoxophyes tea tortrix (Lepidoptera: Tortricidae) is a group of leaf rollers that cause enormous economic losses on tea and apple crops. In East Asia, taxonomic ambiguity of the Adoxophyes orana complex (AOC), which consists of A. orana, A. dubia, A. honmai, and A. paraorana, has persisted for decades because of vague diagnostic characters. In this study, differences in the AOC were examined to improve species identification, determine genetic variations, and develop control strategies. Analyses revealed that A. orana comprised 2 lineages, a widely distributed Palearctic lineage and an East Asian lineage that was nested with other Asian species. Genetic divergence of >3% is proposed to confirm the AOC species that would benefit subsequent taxonomic revision. The monophyletic Taiwanese A. sp. with 2.8–4% from other AOC species appeared to suggest it as an independent taxon, and low interspecific divergence between A. honmai and A. dubia of 0.3% indicated possibility of recent divergence or intraspecific variations. Our result further suggested that the Z9-14:Ac ratio of semiochemicals could be a reference for the reblending of pheromone attractants in Taiwanese tea plantations. Moreover, the AOC species appeared to have a tendency of specific geographic distributions, with A. dubia and A. honmai in Japan and China, A. paraorana in Korea, and A. sp. in Taiwan. Maintaining the unique genetic composition of Adoxophyes species in each geographic region and preventing the possible invasions into those AOC-free countries through the transportation of host plants are essential in managing the AOC in East Asia.

We investigated the usurpation behavior of the hornet Vespa basalis Smith in nests of V. velutina Lepeletier. We collected 47 nests of the two species in Taiwan in their establishment and growth stages. Of these, 29 were mixed-species nests, and in at least 16 V. velutina was replaced by V. basalis. While most nests were initiated by V. velutina, V. basalis coexisted with it during the establishment stage, leading to intense conflict between the two. The multiplex PCR method gave evidence of the usurper’s eggs and larvae in the mixed-species nest. Over time, the number of adults and brood in usurped V. velutina nests decreased, while those of V. basalis increased, demonstrating behavior in V. basalis akin to facultative social parasitism. This study provides further evidence of nest usurpation in the genus Vespa, along with description of complex interactions among these hornets, their natural enemies, prey, and humans in Taiwan.

Lasioglossum albescens (Smith, 1853) is recorded from Taiwan for the first time. The specimens were collected in the Kinmen Islands, several kilometers east of Xiamen, in Fujian, China. This species is distinguished from the other Taiwanese Lasioglossum (Ctenonomia) species by a combination of male clypeus black, mesoscutum with relatively sparse punctures between parapsidal and median lines in both sexes, and first metasomal tergum without distinct punctures and with distinct tessellation over entire surface in both sexes.

Species-specific primers were designed from reference sequences of Nephotettix cincticeps (Uhler), Nephotettix malayanus Ishihara et Kawase, Nephotettix nigropictus (Stål), and Nephotettix virescens (Distant) (Hemiptera: Cicadellidae) and applied in multiplex polymerase chain reaction (PCR) for the molecular identification. The assay yielded distinct amplicons of 263 bp for N. malayanus, 320 bp for N. virescens, 401 bp for N. cincticeps, and 502 bp for N. nigropictus, enabling clear resolution by agarose gel electrophoresis. This method provides a reliable and efficient approach for field surveys and population monitoring of rice green leafhoppers, and is expected to greatly reduce misidentification while providing robust support for pest management decision-making.