In this study, Ni-Y2O3 powder was prepared by alloying recomposition oxidation sintering (AROS), solution combustion synthesis (SCS), and conventional mechanical alloying (MA). The microstructure and mechanical properties of the alloys were investigated by spark plasma sintering (SPS). Among the Ni-Y2O3 powders synthesized by the three methods, the AROS powder had approximately 5 nm of Y2O3 crystals uniformly distributed within the Ni particles, whereas the SCS powder contained a mixture of Ni and Y2O3 nanoparticles, and the MA powder formed small Y2O3 crystals on the surface of large Ni particles by milling the mixture of Ni and Y2O3. The average grain size of Y2O3 in the sintered alloys was approximately 15 nm, with the AROS sinter having the smallest, followed by the SCS sinter at 18 nm, and the MA sinter at 22 nm. The yield strength (YS) of the SCS- and MA-sintered alloys were 1511 and 1688 MPa, respectively, which are lower than the YS value of 1697 MPa for the AROS-sintered alloys. The AROS alloy exhibited improved strength compared to the alloys fabricated by SCS and conventional MA methods, primarily because of the increased strengthening from the finer Y2O3 particles and Ni grains.

Apolygus is one of speciose genus in subfamily Mirinae, including more than 80 species worldwide. Most of Apolygus species are phytophagous, and some species are regard as severe crop pest. For that, precise diagnosis and classification for this genus is crucial. In this work, we provide checklist of Korean Apolygus species with a new species and new distributional records. Diagnostic characters of the new species are discussed with the illustrations of adult male, female specimen and genitalic structures. A key to the Korean Apolygus is also presented.

Miridae show remarkable diversity (>11,700 spp.), accounting for a quarter of all Heteroptera. However, their phylogeny and evolutional history is still remain unclear. In this work, we provide new suggestions for the phylogeny of Miridae using a larger dataset than previous studies. In addition, we suggest an alternative evolutionary history based on newly calibrated divergence dates for Miridae and its subordinate groups, and present probable factors of the family’s success in terms of species diversity. The entire dataset comprises 16 outgroups and 188 ingroup taxa including all seven known subfamilies and 37 out of 45 known tribes. Each species is aligned as 3,577 bp with six molecular loci (COI, 16S rRNA, 18S rRNA, 28S rRNA D3 region, H2A, and H3A).

Cylapine plant bug, Bothriomiris gotohi Yasunaga, 2000 and Peritropis advena Kerzhner, 1972 is reported from Korean peninsula for the first time. Morphological diagnosis for the genus is provided with dorsal habitus, female and male genital structure of Korean Cylapinae species. Also, keys to genera and to species of Korean Cylapinae provided for proper identification.

The orthotyline plant bug genus Ulmica is reported from Korean peninsula for the first time with one new species, Ulmica sp. sp. nov. Morphological diagnosis, the dorsal habitus and genitalia of both sexes are figured for new species. A key to the world Ulmica species is also provided to aid in their identification.

Mirinae is the most diverse subfamily within the family Miridae (Hemiptera: Heteroptera), and includes more than 4,000 species. In Korea, mirids were first recorded from Jeju Island in the mid-1960s. Since that study, numerous plant bug species from the Korean peninsula have been newly recognized and described. Previously, 101 species of Mirini were recorded from Korean peninsula. In this study, we provide an additional information of Mirini in Korea with a description of new species and new records.

In this paper, two species of Mirine plant bug, Pinalitopsis rhodopotnia Yasunaga, Schwartz and Cherot, 2002 andYamatolygus pilosus (Yasunaga, 1992) are newly recorded from Korean peninsula. The dorsal habitus and genital structureof each species were provided. Also, figure of allied species, Pinalitus nigriceps Kerzhner, 1988 and P. rubeolus (Kulik,1965) are also documented to aid in the identifications of allied species.

In this paper, two species of Mirine plant bug, Polymerus amurensis Kerzhner, 1988 and Rhabdomiris striatellus Fabricus, 1794 are newly recorded from Korean peninsula. The dorsal habitus and genital structure of each species were provided. Also, figure of related species, P. pekinensis Horvath, 1901 and R. pulcherrimus Lindberg, 1934 were also documented to aid in the identifications of newly recorded species respectively.

Genus Phytocoris Fallén, 1814 is the largest genus among Heteroptera, around 700 species are described worldwide. In this presentation, the genus Phytocoris from Korean Peninsula is reviewed for the first time with eight species, includes one new record, P. minakatai and one new species, P. goryeonus sp. nov. For further comprehension of this genus, figures of dorsal habitus, genitalia and diagnosis of each Phytocoris species are provided.